JPH0781142B2 - Liquid crystal composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a chiral smectic liquid crystal composition containing two or more kinds of liquid crystal substances.

[Prior Art] Liquid crystal display devices are widely used for various digital displays such as personal computers, calculators and watches.

Conventionally, as a liquid crystal material used in these liquid crystal display devices, a nematic low molecular weight liquid crystal compound, which has a low electric field response speed and a low pixel density, has been replaced with a strong bistability and a high electric field response. Dielectric low molecular weight liquid crystal compounds have been proposed (JP-A-56-107216, US Pat. No. 4,367,924, etc.).

However, the conventionally proposed ferroelectric low-molecular liquid crystal compound must be used with a cell thickness smaller than the spiral pitch of the ferroelectric low-molecular liquid crystal compound, that is, several microns in order to exert its performance. In addition, there is a tendency for compounding defects to occur.

Therefore, there is a drawback that it is difficult to make a large screen.

As a method for solving this problem, a ferroelectric polymer liquid crystal having good orientation and film forming property has been developed (Japanese Patent Laid-Open No. 63-99204).
JP-A-63-264629, etc.). However,
The ferroelectric polymer liquid crystal can obtain a good alignment film and exhibits an electric field response speed equivalent to that of the low molecular weight nematic liquid crystal, but has a drawback that the electric field response speed is slower than that of the low molecular weight ferroelectric liquid crystal.

Therefore, conventionally, in order to maintain a good orientation and improve the electric field response speed, the helical pitch is twisted in opposite directions, and the optically active polymer liquid crystal compound having asymmetric carbon and A chiral smectic liquid crystal composition containing a molecular liquid crystal compound has been proposed (JP-A Sho
63-289090 publication).

However, in this liquid crystal composition, the helical pitch length of the low-molecular liquid crystal is adjusted by the optically active polymer liquid crystal compound having asymmetric carbon, and it is difficult to obtain a uniform one because the dispersibility is different. There is a drawback of.

[Problems to be Solved by the Invention] Under the circumstances, the present invention has a high response speed,
The purpose of the present invention is to provide a liquid crystal composition which is excellent in film-forming property and orientation and can be formed into a large screen, and which can be easily adjusted.

[Means for Solving the Problems] As a result of intensive studies to achieve the above-mentioned object, the inventors of the present invention have found that a low-molecular liquid crystal is added to a side chain type liquid crystal oligomer having an asymmetric carbon of 2 to 4 mer. It was found that the object can be achieved by mixing a compound or a side chain type high molecular weight liquid crystal compound, and the present invention has been completed based on this finding.

That is, the first invention of the present application is to provide a chiral smectic liquid crystal composition containing a side chain type liquid crystal oligomer having an asymmetric carbon of 2 to 4 and a low molecular weight liquid crystal compound. The second invention provides a chiral smectic liquid crystal composition comprising a side chain type liquid crystal oligomer having a dimeric to tetrameric asymmetric carbon and a side chain type polymer liquid crystal compound.

Hereinafter, the first invention and the second invention of the present application will be described in detail.

2 used in the first and second inventions of the present application
Examples of the liquid crystal oligomer having a tetrameric asymmetric carbon include a ferroelectric liquid crystal oligomer and a cholesteric liquid crystal oligomer. Ferroelectric liquid crystal oligomers include, for example, acrylate main chain liquid crystal oligomers, methacrylate main chain liquid crystal oligomers, chloroacrylate main chain liquid crystal oligomers, oxirane nest chain liquid crystal oligomers, siloxane main chain liquid crystal oligomers, and ester main liquid crystal oligomers. A chain liquid crystal oligomer and the like are included.

Examples of the repeating unit of the acrylate main chain liquid crystal oligomer include, for example, And so on.

Examples of the repeating unit of the methacrylate main chain liquid crystal oligomer include, for example, And so on.

Examples of the repeating chloroacrylate main chain liquid crystal oligomer include, for example, And so on.

Examples of the repeating unit of the oxirane main chain liquid crystal oligomer include, for example, And so on.

As the repeating unit of the siloxane main chain liquid crystal oligomer, for example, And so on.

As the repeating unit of the ester main chain type liquid crystal oligomer, for example, And so on.

In the repeating unit of the above-mentioned ferroelectric liquid crystal oligomer, the side chain skeleton may be replaced with a biphenyl skeleton, a phenylbenzoate skeleton, a biphenylbenzoate skeleton, or a phenyl 4-phenylbenzoate skeleton. The benzene ring of may be replaced by a pyrimidine ring, a pyridine ring, a pyridazine ring, a pyrazine ring, a tetrazine ring, a cyclohexane ring, a dioxane ring, a dioxaborinane ring, or a halogen group such as fluorine or chlorine or a cyano group. Well, 1-methylalkyl group, 2-fluoroalkyl group, 2-chloroalkyl group,
2-chloro-3-methylalkyl group, 2-trifluoromethylalkyl group, 1-alkoxycarbonylethyl group, 2-alkoxy-1-methylethyl group, 2-alkoxypropyl group, 2-chloro-1-methylalkyl group ,
It may be replaced by an optically active group such as a 2-alkoxycarbonyl-1-trifluoromethylpropyl group, and the length of the spacer may be changed in the range of 2 to 30 in the methylene chain length.

The cholesteric liquid crystal oligomer includes, for example, an acrylate liquid crystal oligomer, a methacrylate liquid crystal oligomer, and a siloxane liquid crystal oligomer.

As the repeating unit of the acrylate liquid crystal oligomer, for example, And so on.

Examples of the repeating unit of the methacrylate liquid crystal oligomer include, for example, And so on.

As the repeating unit of the siloxane-based liquid crystal oligomer,
For example And so on.

Incidentally, the repeating unit of the cholesteric liquid crystal oligomer, the skeleton of the side chain, fluorine, a halogen group such as a chlorine group, or a biphenyl skeleton which may have a cyano group, a phenyl benzoate skeleton, a biphenyl benzoate skeleton, It may be replaced with a phenyl 4-phenylbenzoate skeleton, and the benzene ring in these skeletons has a pyrimidine ring, a pyridine ring, a pyridazine ring, a pyrazine ring,
It may be replaced with a tetrazine ring, a cyclohexane ring, a dioxane ring, a dioxaborinane ring, etc., the terminal group may be replaced with a linear or branched alkyl group, a haloalkyl group, a cyano group, etc. That is, the methylene chain length may vary in the range of 1 to 30.

The side chain type liquid crystal oligomer having an asymmetric carbon of 2 to 4 mer has one type or two or more types of repeating units as described above.
~ 4 quantified.

The liquid crystal oligomer having a dimer to tetramer asymmetric carbon can be produced by a known polymerization method.

In the polymerization reaction, in order to reduce the production amount of the polymer liquid crystal compound having a degree of polymerization of 5 or more and obtain a large amount of the liquid crystal oligomer having a degree of polymerization of 2 to 4, the amount of the polymerization initiator used with respect to the monomer is increased, It is effective to add a chain transfer agent and shorten the polymerization time. When the polymerization reaction product contains a high-molecular liquid crystal compound having a degree of polymerization of 5 or more, the 2- to 4-mer liquid crystal oligomer in the polymerization reaction product can be collected by various known methods such as column chromatography. Can be separated by. Among the methods for producing a liquid crystal oligomer having a repeating unit of formula (H) or a derivative thereof, a suitable method will be described below.

As shown in the above reaction formula, first, in a solvent such as benzene, in the presence of an esterification catalyst such as concentrated sulfuric acid or p-toluenesulfonic acid, 4'-hydroxybiphenyl-4-carboxylic acid and (R ) -2-Methylbutanol, (S) -2-methylbutanol, etc. are reacted with an optically active alcohol to produce a hydroxy ester form. At this time, it is preferable to carry out the reaction under reflux of a solvent to distill off the water generated in the reaction out of the system.

Then, the hydroxy ester thus obtained, 1,6-dibromohexane, 1,8-dibromooctane,
1,10-dibromodecane, 1,11-dibromoundecane, 1,
12-dibromododecane, 1,16-dibromohexadecane,
A linear α, ω-dibromoalkane such as 1,20-dibromoicosane and an alkali such as potassium hydroxide, sodium hydroxide, potassium carbonate or sodium carbonate in a suitable solvent such as acetone. At a desired temperature to produce the monobromo compound represented by the above formula (XI).

Next, this monobromo compound and dimethylolacetic acid, dimethylolcarboxylic acid such as 2,2-dimethylolpropionic acid, and 2,2-dimethylolacetic acid are combined with a suitable solvent such as dimethylformamide in a solvent such as tetrahydroxy hydroxide. In the presence of alkali such as methylammonium,
The reaction is carried out at a desired temperature to produce the compound represented by the above formula (XII).

Finally, the compound represented by the general formula (XII) thus obtained, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, decane-1,10-dicarboxylic acid, dodecane Polycondensation of a dicarboxylic acid dichloride such as -1,12-dicarboxylic acid with a dihydrochloride such as pyridine in a suitable solvent such as toluene at a desired temperature. Thus, a liquid crystal oligomer having a repeating unit represented by the general formula (XIII) can be produced.

In the above reaction, 4- (4'-hydroxyphenoxycarbonyl) benzoic acid, 4 '-(4 "-hydroxyphenoxycarbonyl) biphenyl-4-carboxylic acid instead of 4'-hydroxybiphenyl-4-carboxylic acid Alternatively, by using a hydroxycarboxylic acid such as 4- [4 ′-(4 ″ -hydroxyphenyl) phenoxycarbonyl] benzoic acid, a liquid crystal oligomer having a repeating unit represented by the following general formula can be produced.

(2) The skeleton and the optically active group are In the case of, the etherification reaction, esterification reaction, polycondensation reaction and the like in each reaction step can be produced by performing the same operation as in (1) according to the following reaction formula. However, in the etherification reaction of α, ω-dibromoalkane with 4-hydroxybenzoic acid, it is preferable to protect the carboxyl group of 4-hydroxybenzoic acid by previously esterifying it with a benzyl group or the like.

(3) The skeleton and the optically active group In the production method of (2) above, instead of 4-hydroxybenzoic acid, 4'-hydroxybiphenyl-
Other than using 4-carboxylic acid, it can be manufactured by performing the same operation.

(4) The skeleton and the optically active group In the above production method (2), the same operation can be performed except that 4'-hydroxybiphenyl-4-carboxylic acid benzyl ester is used instead of 4-hydroxybenzoic acid benzyl ester.

A method for producing a liquid crystal oligomer having the repeating unit of formula (I) and its derivative will be described below.

As shown in the above reaction formula, diethyl malonate
-Alkylation with dibromoalkane (III). The obtained monobromo ester form is reacted with 4-hydroxybenzoic acid ethyl ester to be etherified to obtain an ester form. This ester form is saponified to form a tricarboxylic acid form. On the other hand, 4'-hydroxybiphenyl-4-carboxylic acid is reacted with an optically active alcohol (IV) to be esterified to obtain a hydroxy form. The tricarboxylic acid body obtained above is selectively esterified with this hydroxy body to obtain the desired dicarboxylic acid body.

The polycondensation reaction of this dicarboxylic acid compound is carried out by first converting the dicarboxylic acid compound into an acid halide with an acid halogenating agent such as thionyl chloride in a solvent such as toluene, and then using the obtained acid halide in the presence of triethylamine or the like, tetrahydrofuran. It is carried out by reacting at a desired temperature in a solvent such as.
A liquid crystal oligomer can be produced by this method.

These side chain type liquid crystal oligomers having a dimer to tetramer asymmetric carbon may be used alone or in combination of two or more.

When two or more side chain type oligomers having 2 to 4 mer asymmetric carbons are mixed and used, it is easy to adjust the pitch length by using the ferroelectric liquid crystal oligomers in which the spiral twist directions are opposite to each other. Can be done.

Examples of the low molecular weight liquid crystal compound used in the first invention of the present application include:
For example, ferroelectric low molecular weight liquid crystal compounds, non-chiral liquid crystal compounds and the like are mentioned.

Examples of the ferroelectric low molecular weight liquid crystal compound include Schiff base type ferroelectric low molecular weight liquid crystal compound, azo and azoxy type ferroelectric low molecular weight liquid crystal compounds, biphenyl and aromatic ester type ferroelectric low molecular weight liquid crystal compounds, halogens. Examples thereof include a ferroelectric low molecular weight liquid crystal compound having a ring substituent such as a cyano group, and a ferroelectric low molecular weight liquid crystal compound having a heterocycle.

Examples of the Schiff base ferroelectric low-molecular liquid crystal compound include compounds (1) to (14) shown below.

Examples of the azo- and azoxy-based ferroelectric low-molecular liquid crystal compounds include (15) and (16) shown below.

As the biphenyl and aromatic ester-based ferroelectric low-molecular liquid crystal compounds, for example, the following compounds (1
7) to (34).

Examples of the ferroelectric low molecular weight liquid crystal compound into which a ring substituent such as a halogen or a cyano group is introduced include the compounds (35) to (37) shown below.

Examples of the ferroelectric low molecular weight liquid crystal compound having a heterocycle include compounds (38) to (41) shown below.

In addition to the above compounds, for example, the following compounds (42) to (46) may be mentioned.

The above compounds are typical compounds of the ferroelectric low molecular weight liquid crystal compound, and the ferroelectric low molecular weight liquid crystal compound of the present invention is not limited to these structural formulas.

Non-chiral liquid crystal compounds include, for example, JP-A-61-2916.
79, JP-A-62-240378, JP-A-62-44548
Examples thereof include the compounds described in JP-A No. Some of the non-chiral liquid crystal compounds described in these publications are as follows.

(R ₁ and R ₂ represent a linear or branched alkyl group having 1 to 12 carbon atoms and may be the same or different.) (R ₁ and R ₂ represent an alkyl group or an alkoxyl group having 5 to 14 carbon atoms and may be the same or different.) The low molecular weight liquid crystal compound may be used alone or in combination of two or more. You may use it.

When two or more low molecular weight liquid crystal compounds are used as a mixture, the pitch length can be easily adjusted by using the ferroelectric liquid crystal compounds whose spiral twist directions are opposite to each other.

In the first invention of the present application, the side chain type liquid crystal oligomer having the 2- to 4-mer asymmetric carbons and the low-molecular liquid crystal compound are mixed, but the side chain liquid crystal having the 2- to 4-mer asymmetric carbons is used. The mixing ratio of the oligomer is usually 10 to 90 mol%, preferably 10 to 40 mol%. Examples of the side chain type polymer liquid crystal compound used in the second invention of the present application include a ferroelectric polymer liquid crystal compound and a cholesteric polymer. Examples thereof include polymer liquid crystal compounds having asymmetric carbon such as polymer liquid crystal compounds, nematic polymer liquid crystal compounds and polymer liquid crystal compounds having no asymmetric carbon such as smectic polymer liquid crystal compounds.

The ferroelectric polymer liquid crystal compound has one or more kinds of repeating units similar to those of the ferroelectric liquid crystal oligomer,
The degree of polymerization is 5 to 2000.

The cholesteric polymer liquid crystal compound means one or two repeating units similar to those of the cholesteric liquid crystal oligomer.
It has one or more species and a degree of polymerization of 5 to 2000.

Examples of nematic polymer liquid crystal compounds include polyacrylate nematic polymer liquid crystal compounds, polymethacrylate nematic polymer liquid crystal compounds, and polysiloxane nematic polymer liquid crystal compounds.

Examples of the repeating unit of the polyacrylate nematic polymer liquid crystal compound include, for example, And so on.

As the repeating unit of the polymethacrylate nematic polymer liquid crystal compound, for example, And so on.

Examples of the repeating unit of the polysiloxane-based nematic polymer liquid crystal compound include, for example, And so on.

Further, the repeating unit of the nematic polymer liquid crystal compound is a biphenyl skeleton that may have a halogen group such as a fluorine or chlorine group, a phenylbenzoate skeleton, a biphenylbenzoate skeleton, or a phenyl-4-phenylbenzoate skeleton. The benzene ring in the skeleton that may be replaced with a pyrimidine ring, a pyridine ring, a pyridazine ring, a pyrazine ring, a tetrazine ring, a cyclohexane ring, a dioxane ring,
It may be replaced with a dioxaborinane ring or the like, the terminal group may be replaced with a linear or branched alkyl group and a haloalkyl group, a cyano group or the like, and the length of the spacer is in the range of methylene chain length 1 to 30. You may change with.

Examples of the smectic polymer liquid crystal compound include polyacrylate-based smectic polymer liquid crystal compounds, polymethacrylate-based smectic polymer liquid crystal compounds, polyoxirane-based smectic polymer liquid crystal compounds, polysiloxane-based smectic polymer liquid crystal compounds, polyester-based smectic Examples thereof include high molecular weight liquid crystal compounds.

Examples of the repeating unit of the polyacrylate smectic polymer liquid crystal compound include, for example, And so on.

As the repeating unit of the polymethacrylate smectic polymer liquid crystal compound, for example, And so on.

Examples of the repeating unit of the polyoxirane-based smectic polymer liquid crystal compound include, for example, And so on.

Examples of the repeating unit of the polysiloxane-based smectic polymer liquid crystal compound include: And so on.

Examples of the repeating unit of the polyester smectic polymer liquid crystal compound include, for example, And so on.

The skeleton of the mesogen portion of the repeating unit of the above smectic polymer liquid crystal compound may be replaced with a biphenyl skeleton, a phenylbenzoate skeleton, a biphenylbenzoate skeleton, a phenyl-4-phenylbenzoate skeleton, or the like. The benzene ring therein may be replaced with a pyrimidine ring, a pyridine ring, a pyridazine ring, a pyrazine ring, a tetrazine ring, a cyclohexane ring, a dioxane ring, a dioxaborinane ring, a halogen group such as a fluorine or chlorine group, or a cyano group. May have a terminal group may be replaced with a linear or branched alkyl group and a haloalkyl group, a cyano group, and the like,
Further, the length of the spacer may be changed within the range of methylene chain length 1 to 30. Other JP-A-63-99204, 63
There are also mentioned those in which the optically active group in the repeating unit of the ferroelectric polymer liquid crystal described in JP-A-264629 is replaced with an inactive group. These repeating units may be contained in the polymer, and two or more kinds of repeating units may be contained.

The degree of polymerization of the polymer liquid crystal compound containing no asymmetric carbon is usually in the range of 5 to 2000.

These high molecular weight liquid crystal compounds may be used alone,
You may mix and use 2 or more types.

In the second invention of the present application, the side chain type liquid crystal oligomer having the asymmetric carbon of the dimer to the tetramer is mixed with the polymer liquid crystal compound, but the liquid crystal oligomer having the asymmetric carbon of the dimer to the tetramer is mixed. The proportion is usually 5 to 95% by weight, preferably 10 to
90% by weight.

It should be noted that the chiral smectic liquid crystal compositions of the first invention and the second invention of the present application may contain other substances such as a polymer, an adhesive and a plasticizer, if necessary.

EXAMPLES Next, the first invention of the present application and the second invention of the present application will be specifically described with reference to examples, but the invention is not limited to these examples.

In the examples, the response speed to electric field, the contrast ratio, and the spiral pitch were measured by the following measuring methods.

(1) Electric field response speed A liquid crystal was sandwiched between two ITO glass substrates and a shearing method was used to prepare an alignment cell having a thickness of 2 μm. Furthermore, an electric field of ± 20 MV / m was applied under crossed Nicols, and the time required for the change in light transmittance at that time to reach 0% to 90% was measured.

(2) Contrast ratio A horizontally aligned cell having a thickness of 1 to 4 μm was prepared and measured by the ratio of transmitted light intensity when the sign of the applied electric field was reversed under crossed Nicols.

(3) Helical pitch A horizontal alignment cell having a thickness of 100 μm was prepared, and the stripe pattern interval was measured with a polarization microscope.

Example 1 A is a trimer obtained by separating the polymer obtained by the production method described in JP-A-63-161005 by column chromatography.

A liquid crystal composition having an Sm ^* C phase was obtained by mixing the above A and B. When the response time was examined, it was almost the same as the response time of the low molecular weight liquid crystal compound alone when the composition of the low molecular weight liquid crystal compound was 70 mol% or more.

Phase transition of (A) + (B) (A: B molar ratio 3: 7) Examples 2-11 A: A and A are trimers obtained by separating the polymer obtained by the production method described in JP-A-63-99204 by column chromatography.

In the combinations shown in Table 1, it was confirmed that the compositions in which the side chain type liquid crystal oligomer listed in A was added to the low molecular weight liquid crystal compound listed in B in an amount of 20 mol% all had an SmC ^* phase.

Encapsulate these compositions in a glass substrate with ITO with a cell gap of 100μ that has been rubbed and then isotropic (80 ℃)
To an SmC ^* phase (25 ° C) and observed the alignment state with a polarizing microscope. As a result, a better monodomain was obtained and the normal direction of the layer surface was rubbed compared to the case of using the low molecular weight liquid crystal compound alone. It was in line with the direction. It was also confirmed that the spontaneous polarization value (PS) was hardly reduced as compared with the case of using the low molecular weight liquid crystal compound alone.

Example 12 The mixed liquid crystal compositions shown in Examples 2 to 11 were formed into a film having a thickness of 15 μm from the molten state (100 ° C.), and the surface speed was 2
Two PET films (100 μm) sandwiched between two roller pairs of m / min and 3 m / min, uniaxially stretched, and slowly cooled from SmA phase (80 ° C) at 5 ° C / min. It was confirmed by observation with a polarizing microscope that a good oriented film was obtained.

Example 13 When the side chain type liquid crystal oligomer A is 20% by weight or more in the above mixed system,
A liquid crystal composition having an SmC ^* phase was obtained.

The response speed, the contrast ratio, and the spiral pitch in the mixing of the weight ratio of A: B = 2: 8 are shown below.

A is a dimer obtained by separating the polymer obtained by the production method described in JP-A-63-99204 by column chromatography.

B was produced by the production method described in Polymer Commun. 1986. Volume 27, page 190.

Example 14 A liquid crystal composition having an SmC ^* phase with 20% by weight or more of A in the above mixed system was obtained.

The response speed, the contrast ratio, and the spiral pitch in the mixing of the weight ratio of A: B = 5: 5 are shown below.

A and B are Mol.Cryst.Liq.Cryst.1986. Vol.137,
It was produced by the production method described on page 349, Makromol. Chem. 1978, Volume 179, page 2541.

Example 15 A composition having an SmC ^* phase with 20% by weight or more of A in the above mixed system was obtained.

The response speed, the contrast ratio, and the spiral pitch in the mixing of the weight ratio of A: B = 5: 5 are shown below.

A and B are Mol.Cryst.Liq.Cryst.1986. Vol.137,
It was produced by the production method described on page 349, Polymer Commun. 1986. Volume 27, page 190.

Example 16 A composition having an SmC ^* phase with 20% by weight or more of A in the above mixed system was obtained.

The response speed, the contrast ratio, and the spiral pitch in the mixing of the weight ratio of A: B = 5: 5 are shown below.

A was manufactured by the manufacturing method described in JP-A-63-264629.

Example 17 A composition having an SmC ^* phase with 20% by weight or more of A in the above mixed system was obtained.

The response speed, the contrast ratio, and the spiral pitch in the mixing of the weight ratio of A: B = 5: 5 are shown below.

A was manufactured by the following method.

Liquid crystal unit: 4 '-(9-decenyloxy) biphenyl-4-carboxylic acid 2-methylbutyl ester Synthesis of 10-chloro-1-decene 5.0 g and sodium iodide 12 g
Was dissolved in 50 ml of methyl ethyl kettle and stirred at 80 ° C. for 11 hours. After the reaction, it was washed with water, the organic phase was dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure. Thereto, 6.5 g of 4'-hydroxybiphenyl-4-carboxylic acid 2-methylbutyl ester, 3.3 g of potassium carbonate and 50 ml of methyl ethyl ketone as a solvent were added, and the reaction was carried out at 80 ° C for 28 hours.
After the reaction, the inorganic substances were removed by washing with water. After drying over magnesium sulfate, the solvent was distilled off under reduced pressure. The obtained crude product was recrystallized from ethanol and purified to obtain the above-mentioned 4 '.
7.9 g of-(9-decenyloxy) biphenyl-4-carboxylic acid 2-methylbutyl ester was obtained. (Yield 81%).

5.4 g of 4 '-(9-decenyloxy) biphenyl-4-carboxylic acid 2-methylbutyl ester obtained in the synthesis of liquid crystal polymer and 0.69 g of polymethylhydrosiloxane were dissolved in 20 ml of toluene. 3 mg of chloroplatinic acid hexahydrate was added as a catalyst, and the reaction was carried out at 80 ° C. for 30 hours in an argon atmosphere to obtain 2.0 g of the desired liquid crystal polymer. The obtained polymer was separated by column chromatography.

B was produced by the production method described in Polymer Bulletin. 1986. Volume 16, page 521.

Example 18 A composition having an SmC ^* phase with 20% by weight or more of A in the above mixed system was obtained.

The response speed, the contrast ratio, and the spiral pitch in the mixing of the weight ratio of A: B = 5: 5 are shown below.

A was manufactured by the following method.

Synthesis of 4'-hydroxybiphenyl-4-carboxylic acid 2-methylbutyl ester 4'-hydroxybiphenyl-4 in 150 ml of benzene
-Carboxylic acid 93 mmol (20 g), (S)-(-)-2-methylbutanol 467 mmol (41 g) and concentrated sulfuric acid 2 ml were added, and this was refluxed for 24 hours using a Dean-Stark tube to carry out the esterification reaction. went. After completion of the reaction, the reaction solution was concentrated, and the obtained product was recrystallized with a toluene-hexane mixed solvent to obtain a hydroxy ester compound. The melting point of this hydroxyester compound was 116.2 to 117.8 ° C, and the yield was 98%. The structural formula of this product is shown below.

Synthesis of 4 '-[4 "-(12-bromododecyloxy) benzoyloxy] biphenyl-4-carboxylic acid 2-methylbutyl ester 50 mmol (19.3 g) of the carboxylic acid derivative represented by was stirred in 30 ml of toluene and 10 ml of thionyl chloride at 80 ° C. for 2 hours.
Next, excess thionyl chloride and toluene were distilled off under reduced pressure to obtain an acid chloride. 55 mmol (15.6 g) of the hydroxy ester compound obtained in 1. and 60 mmo of triethylamine
A solution of 1 (6.1 g) in THF (200 ml) was stirred, the acid chloride solution (THF) obtained above was added dropwise, and the mixture was stirred for 8 hours. After the reaction, extract with ether, wash with diluted HCI water, dry, and concentrate, then purify by column chromatography to obtain the desired product. Was obtained with a yield of 73%. ▲ [α] of this thing
²³ _D ▼ was + 2.33 ° (CHCI ₃ ).

Synthesis of 4 ′-[4 ″-{12- (2,2-dimethylolpropionyloxy) dodecyloxy} benzoyloxy] biphenyl-4-carboxylic acid 2-methylbutyl ester 2,2-dimethylolpropionic acid 18.1 mmol (2.4 g) and tetramethylammonium hydroxide (pentahydrate) 20.0 mmol
(3.6 g) was stirred in 150 ml of DMF for 2 hours. Next, 18.0 mmol (11.7 g) of the monobromo compound obtained in was added, and the mixture was stirred for 6 hours. After the reaction, extract with ether, dry and concentrate,
Purify by column chromatography to obtain the target formula The ester compound represented by was obtained in a yield of 78%. This thing ▲
The [α] ²³ _D ▼ was + 2.10 ° (CHCI ₃ ).

Polycondensation reaction Next, the ester compound obtained as the ester compound 1.7mmo
Using l (1.20 g), a polycondensation reaction was performed using 1.7 mmol (0.29 g) of glutaric acid dichloride as the carboxylic acid dichloride, A polymer having a repeating unit represented by The obtained polymer was separated by column chromatography.

B was produced by the production method described in Makromol. Chem. Rapid. Commun. 1987. Vol. 8, page 59.

Example 19 8 parts by weight of a side chain type ferroelectric liquid crystal oligomer (A) having a polyacrylate main chain and 2 parts by weight of a ferroelectric polymer liquid crystal (B) having a polyoxirane main chain were mixed, 15% by weight of ferroelectric liquid crystal composition dissolved in dichloromethane
Solution. PES substrate with ITO electrode (thickness 125 μm, width 1
The above solution was applied to a roll having a length of 5 cm and a length of 50 m) by using a microgravure coater, and after evaporation of the solvent, a film having a thickness of about 3 μm was obtained. Laminate the same type of PES substrate as the opposite substrate,
Bending orientation treatment as shown in FIG. 1 was performed. Orientation treatment: roll diameter φ80mm, line speed v = 3m / min, first roll temperature
The conditions were 110 ° C., second roll temperature 90 ° C., third roll temperature 85 ° C., and fourth roll temperature 20 ° C.

After the above-mentioned orientation treatment, it was left at room temperature for about 1 hour, and after the epoxy resin was almost cured, it was cut to obtain a cell of 15 cm × 30 cm. When the contrast at room temperature was measured under crossed Nicols, a good alignment state of 29 was obtained by applying ± 5 V, and the display was maintained for 24 hours or more even when the electric field was cut off.

In this way, continuous production of a long product (coating → laninate → alignment treatment → cutting) is possible, and a good alignment state can be easily obtained.

When the mechanical strength of the liquid crystal cell was examined, it was 10 kg / cm ² for vertical pressure and a radius of curvature of 3 c for bending deformation at room temperature.
The contrast and bistability did not change with the deformation up to m.

[Effects of the Invention] As described above, according to the configurations of the first invention and the second invention of the present application, the response speed to an electric field is high, the film forming property,
A chiral smectic liquid crystal composition having excellent orientation can be obtained. In particular, the first invention of the present application has a high response speed to an electric field, and the second invention of the present application has a large mechanical strength.

The chiral smectic liquid crystal composition of the first invention and the second invention of the present application is used for a display device such as a clock and a calculator, an electronic optical shutter, an electronic optical diaphragm, an optical communication optical path changeover switch, an optical modulator, a liquid crystal printer head, a memory, a focus. It can be used in the field of optoelectronics such as various electro-optical devices such as variable distance lenses.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an alignment treatment step in the example. Reference numerals in the drawing are 1: first roll, 2: second roll, 3: third roll, 4: fourth roll, 5: take-up roll.

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Claims (4)

[Claims] 1. A chiral smectic liquid crystal composition comprising a side chain type liquid crystal oligomer having a dimeric to tetrameric carbon and a low molecular weight liquid crystal compound. 2. The chiral smectic liquid crystal composition according to claim 1, wherein the side chain type liquid crystal oligomer having a dimeric tetramer to a tetramer is a ferroelectric liquid crystal. 3. A chiral smectic liquid crystal composition comprising a side chain type liquid crystal oligomer having a dimer to tetramer asymmetric carbon atom and a side chain type polymer liquid crystal compound. 4. The chiral smectic liquid crystal composition according to claim 3, wherein the side chain type liquid crystal oligomer having a dimer to tetramer asymmetric carbon atom is a ferroelectric liquid crystal.