JPH08283718A - Polymerizable liquid crystal composition and production of optically anisotropic material - Google Patents

Abstract

PURPOSE: To obtain a polymerizable liquid crystal composition showing a smectic liquid crystal phase and easily giving an optically anisotropic material having optically biaxial properties, etc., by using a monofunctional acrylate compound having a liquid crystal skeleton having a plurality of six-membered rings. CONSTITUTION: A cyclic alcohol, a phenol or an aromatic hydroxy compound each having a liquid crystal skeleton having at least two six-membered rings as a partial structure is esterified with (meth)acrylic acid to produce a monofunctional (meth)acrylate compound. The polymerizable liquid crystal composition showing a smectic liquid crystal phase is mainly made of this (meth)acrylic compound. A desirable example of the monofunctional (meth) acrylate compound is a compound of formula I (wherein X is H or methyl; six-membered rings A, B and C are each a group of formula II or III or the like; n is 0 or 1; Y<1> and Y<2> are each a single bond, -CH2 CH2 -, -CH2 O- or the like; Y<3> is a single bond, -COO- or -OCO-; and R is H, a halogen, cyano or the like).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel polymerizable liquid crystal composition used as an optical, display and recording material, an optical compensator for a liquid crystal display and a polarizing prism material, and an optical anisotropic material obtained by polymerizing the composition. The present invention relates to a body and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, a polymer film having a controlled alignment structure of internal molecules has been demanded as a compensating plate in order to satisfy both improvement of display quality and weight saving of a liquid crystal display device. As a technique for responding to this, a method using a liquid crystalline polymer (Japanese Patent Application Laid-Open No. 3-28822, Japanese Patent Application Laid-Open No. 4-28422)
-3022, JP-A-4-55813, JP-A-5-27235, JP-A-5-61039) and a method using a bifunctional liquid crystalline acrylate compound or composition (JP-A-3-14029). ) Are known, but these techniques have problems in the uniformity of the orientation structure of molecules inside the film and the heat resistance of the film.

In order to solve this problem, the present inventors have
The polymerizable liquid crystal composition having liquid crystallinity at room temperature and a polymer film (optical anisotropic body) having a controlled internal alignment structure obtained by photopolymerization of the composition were previously proposed. However, the optically anisotropic bodies of the examples of the invention are those obtained by photopolymerizing a polymerizable liquid crystal composition in a nematic liquid crystal state, although there is no problem in the uniformity of the alignment structure of the molecules inside and the heat resistance. Therefore, it does not have the optical biaxiality necessary for obtaining an optical anisotropic body having a good viewing angle characteristic or a layered structure of a liquid crystal molecular skeleton inside.

[0004]

DISCLOSURE OF THE INVENTION Problems to be solved by the present invention include optical biaxiality and a liquid crystal molecular skeleton inside when producing an optically anisotropic substance by polymerization of a polymerizable liquid crystal composition. Another object of the present invention is to provide a polymerizable liquid crystal composition capable of introducing the above layered structure.

Another object of the present invention is to provide a method for producing an optically anisotropic substance obtained by photopolymerizing the same, and to provide an optically anisotropic substance excellent in the uniformity of the orientation structure of internal molecules and heat resistance.

[0006]

In order to solve the above-mentioned problems, the inventors of the present invention have conducted intensive studies focusing on the polymerizable liquid crystal composition, and as a result, have provided the present invention.

That is, the present invention is a monofunctional acrylate compound or monofunctional methacrylate which is an acrylic acid or methacrylic acid ester of a cyclic alcohol, phenol or aromatic hydroxy compound having a liquid crystalline skeleton having at least two 6-membered rings as a partial structure. Provided is a polymerizable liquid crystal composition containing a compound and exhibiting a smectic liquid crystal phase.

There is also provided a method for producing an optically anisotropic substance, which comprises photopolymerizing the polymerizable liquid crystal composition exhibiting a smectic liquid crystal phase of the present invention, and an optically anisotropic substance obtained by this production method. .

The polymerizable liquid crystal composition of the present invention will be described in more detail below. The acrylate or methacrylate (hereinafter referred to as the polymerizable compound according to the invention) contained in the polymerizable liquid crystal composition of the invention is described in detail in the general formula (I).

[0010]

[Chemical 11]

(In the formula, X represents a hydrogen atom or a methyl group, and the 6-membered rings A, B and C are each independently,

[0012]

[Chemical 12]

And n is an integer of 0 or 1,
m represents an integer of 1 to 4, Y ¹ and Y ² are each independently a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —O.
_{CH 2 -, - COO -,} - OCO -, - C≡C -, - C
H = CH -, - CF = CF -, - (CH 2) 4 -, - CH
_{2 CH 2 CH 2 O -,} - OCH 2 CH 2 CH 2 -, - CH 2 =
CHCH ₂ CH ₂ - or -CH ₂ CH ₂ CH = CH- and represents, Y ³ represents a single bond, -COO -, - OCO- represents,
R is hydrogen atom, halogen atom, cyano group, carbon atom 1
To 20 alkyl groups, alkoxy groups, alkenyl groups or alkenyloxy groups. ).

In the above general formula (I), 6-membered rings A and B
And C are each independently

[0015]

[Chemical 13]

And m is an integer of 1 or 2,
Y ¹ and Y ² each independently represent a single bond or —C≡C—, and R is a halogen atom, a cyano group, or a carbon number of 1 to 1.
It is preferable to represent 20 alkyl, alkoxyl or alkenyl groups.

It is an essential condition that the polymerizable liquid crystal composition of the present invention exhibits a smectic liquid crystal phase. As the smectic liquid crystal phase, various smectic phases classified into a smectic A phase, a smectic C phase and the like are known, but depending on the use of the optically anisotropic substance obtained by photopolymerizing a polymerizable liquid crystal composition. It is preferable to select the type of smectic phase. For example, when optical biaxiality is required, it is preferable to select a smectic liquid crystal phase having a liquid crystal alignment structure in which liquid crystal molecules are inclined at an angle with respect to the layered structure, such as the smectic C phase. preferable. Also uniform 1
In order to easily obtain the axial alignment, it is preferable to select the smectic A liquid crystal phase.

The temperature range in which the polymerizable liquid crystal composition of the present invention develops a smectic liquid crystal phase is preferably 80 ° C. or less in order to prevent unintentional induction of thermal polymerization, and more preferably around room temperature.

The polymerizable liquid crystal composition of the invention is characterized by exhibiting a smectic liquid crystal phase. for that reason,
The phase sequence must have a smectic liquid crystal phase, but those exhibiting a nematic liquid crystal phase at a temperature higher than the upper limit temperature exhibiting the smectic liquid crystal phase are obtained by aligning the polymerizable liquid crystal composition exhibiting the nematic liquid crystal phase. After that, a method of obtaining good alignment of the smectic liquid crystal phase by lowering the temperature can be applied, and therefore it is preferable to use the polymerizable liquid crystal composition having such a phase series. In particular, when a polymerizable liquid crystal composition in which the smectic liquid crystal phase is a smectic A liquid crystal phase and which exhibits a nematic liquid crystal phase at a temperature higher than that of the smectic A liquid crystal phase, uniform uniaxial alignment is easily obtained, which is useful. Is high,
In order to prepare such a composition, at least one ring of the 6-membered rings A, B and C of the above general formula (I) is

[0020]

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And m is an integer of 1 or 2,
Y ¹ , Y ² and Y ³ represent a single bond, and R is a carbon atom of 1
It is preferable to contain a monofunctional (meth) acrylate that represents an alkyl group of ˜20.

Typical examples of the polymerizable compounds according to the present invention and their phase transition temperatures are shown, but the polymerizable compounds usable in the present invention are not limited to these compounds.

[0023]

[Chemical 15]

[0024]

Embedded image

[0025]

[Chemical 17]

(In the above, the cyclohexane ring represents a transcyclohexane ring, and C in the phase transition temperature scheme is used.
Is a crystalline phase, N is a nematic phase, S is a smectic phase, I
Represents an isotropic liquid phase and the numbers represent phase transition temperatures. The polymerizable compound according to the present invention may be used alone or in combination of two or more kinds. When they are used alone, it is necessary that they themselves exhibit a smectic liquid crystal phase. Of course, when two or more compounds are mixed and used,
It is preferable to use a compound which itself exhibits a smectic liquid crystal phase.

Further, a liquid crystal compound having no polymerizable functional group may be added to the polymerizable liquid crystal composition of the present invention in a range such that the total amount in the polymerizable liquid crystal composition does not exceed 10% by weight. Good. As the liquid crystal compound having no polymerizable functional group, a nematic liquid crystal compound, a smectic liquid crystal compound, a cholesteric liquid crystal compound or the like can be used without particular limitation as long as it is recognized as a liquid crystal in this technical field. Smectic liquid crystal compounds are particularly preferred. Also,
As the added amount increases, the mechanical strength of the obtained optical anisotropic body tends to decrease, so that the added amount needs to be adjusted appropriately.

Further, a polymerizable compound which does not exhibit liquid crystallinity can be added. Such compounds may be those generally recognized as polymer-forming monomers or polymer-forming oligomers in this technical field, but acrylate compounds are particularly preferable.

These liquid crystal compounds or polymerizable compounds may be appropriately selected and added in combination, but the addition amount of each component is adjusted so that at least the smectic liquid crystallinity of the resulting polymerizable liquid crystal composition is not lost. It needs to be adjusted.

A photopolymerization initiator or a sensitizer may be added to the polymerizable liquid crystal composition of the present invention for the purpose of improving its polymerization reactivity. Here, examples of the photopolymerization initiator that can be used include known benzoin ethers, benzophenones, acetophenones, benzyl ketals, and the like. The total amount in the polymerizable liquid crystal composition is preferably 10% by weight or less, and particularly preferably 5% by weight or less.

A stabilizer may be added to the polymerizable liquid crystal composition of the present invention in order to improve its storage stability. Examples of the stabilizer that can be used here include known hydroquinone, hydroquinone monoalkyl ethers, and tert-butylcatechol. The amount of the stabilizer added is such that the total amount in the polymerizable liquid crystal composition is 0.
It is preferably not more than 05% by weight.

A dichroic dye may be added to the polymerizable liquid crystal composition of the present invention in order to impart dichroism to the optically anisotropic body. The dichroic dyes that can be used include azo dyes, azoxy dyes, anthraquinone dyes, and perylene dyes, and these dyes can be used alone or in combination. As such a dichroic dye, for example, "LSY
-116 "," LSR-401 "," LSR-40 "
6 "," LSR-426 "," LSB-278 "," L "
SB-350 "(all manufactured by Mitsubishi Chemical Corporation)," SI-20 "
9 "," M-710 "," M-361 "," M-8 "
6 "," M-618 "," SI-252 "," M-77 "
7 "," M-370 "," M-137 "," M-14 "
1 "," M-438 "," M-412 "," M-3 "
4 "," M-430 "," M-406 "," S-30 "
1 ”,“ S-304 ”,“ M-676 ”(above, manufactured by Mitsui Toatsu Co., Ltd.) and the like. The amount of addition of these dichroic dyes depends on the use of the optically anisotropic substance to be produced, but is adjusted so that the total amount in the polymerizable liquid crystal composition is in the range of 0.1 to 10% by weight. Preferably 0.2
The range of 2 wt% is particularly preferred.

Further, a chiral compound is added to the polymerizable liquid crystal composition of the present invention for the purpose of introducing a chiral smectic structure into an optically anisotropic body produced by photopolymerizing the polymerizable liquid crystal composition. Good. The chiral compound that can be used here does not need to exhibit liquid crystallinity by itself, and may or may not have a polymerizable functional group. The direction of the twist can be appropriately selected depending on the purpose of use. Examples of such a chiral compound include cholesterol pelargonate having a cholesteryl group as an optically active group, cholesterol stearate, “CB-15” and “C-15” having a 2-methylbutyl group as an optically active group (above BDH). Company), "S1082" (Merck), "CM-1
9 ”,“ CM-20 ”,“ CM ”(all manufactured by Chisso Corporation),
“S- having a 1-methylheptyl group as an optically active group
811 "(Merck)," CM-21 "," CM-2 "
2 ”(all manufactured by Chisso Corporation). It is preferable that the addition amount of the chiral compound be appropriately adjusted depending on the use of the produced optically anisotropic substance.

The production method of the present invention will be described in more detail below. The production method of the present invention, the polymerizable liquid crystal composition showing a smectic liquid crystal phase of the present invention, after orienting in a certain direction on the substrate or between the substrates, photopolymerization by irradiation with an energy beam such as an electron beam or ultraviolet rays. Then, the polymer is polymerized to fix the orientation and produce an optically anisotropic body having optical biaxiality and a layered structure inside.

As a means for orienting the polymerizable liquid crystal composition in a certain direction, for example, a substrate whose surface is rubbed with a cloth or a substrate having an orientation film in which SiO ₂ is obliquely vapor-deposited is carried on or between the substrates. A method can be mentioned.

As a method that does not depend on the substrate that has been subjected to the alignment treatment, there can be mentioned, for example, the flow alignment of the polymerizable liquid crystal composition, or the method utilizing an electric field or a magnetic field. These orientation means may be used alone or in combination. Among them, the method of using a substrate whose surface is rubbed with a cloth or the like is particularly preferable because of its simplicity.

The substrate that can be used at this time may be an organic material or an inorganic material. Specific examples of the organic material include, for example, polyethylene terephthalate, polycarbonate, polyimide,
Polymethylmethacrylate, polystyrene, polyethylene, polyvinyl chloride, polytetrafluoroethylene, polychlorotrifluoroethylene, polyarylate, polysulfone, cellulose, polyetheretherketone,
Further, examples of the inorganic material include silicon and glass.

When proper orientation cannot be obtained by rubbing these substrates with a cloth or the like, an organic thin film such as a polyimide thin film or a polyvinyl alcohol thin film is formed on the surface of the substrate according to a known method, and this is cloth or the like. You may rub with. Further, it is particularly preferable to positively use a polyimide thin film that gives a pretilt angle as used in a normal TN or STN cell because the internal structure of the optically anisotropic body can be controlled more precisely. When the orientation state is controlled by an electric field, a substrate having an electrode layer can be used, and in this case, it is preferable to form an organic thin film such as the above-mentioned polyimide thin film on the electrode.

As the method of polymerization, it is desirable to perform photopolymerization by irradiating the above-mentioned substrate with energy rays such as ultraviolet rays or electron beams, because rapid progress of polymerization is desirable. When photopolymerization is carried out with the polymerizable liquid crystal composition sandwiched between two substrates, at least the substrate on the irradiation surface side must be provided with appropriate transparency. The temperature at this time should be a temperature at which the smectic liquid crystal state of the polymerizable liquid crystal composition in the present invention is maintained, but it is preferable to carry out the polymerization as close to room temperature as possible from the viewpoint of avoiding thermal polymerization.

The optical anisotropic body produced by the method of the present invention may be used by peeling it from the substrate, or may be used as it is on the substrate without being peeled.

[0041]

EXAMPLES The present invention will be described more specifically below by showing examples of the present invention. However, the invention is not limited to these examples.

(Example 1) Formula (e)

[0043]

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50 parts by weight of a compound of formula (f)

[0045]

[Chemical 19]

A polymerizable liquid crystal composition (A) comprising 50 parts by weight of the compound of was prepared. This polymerizable liquid crystal composition has a temperature of 51 ° C.
The phase transition from the crystal phase to the smectic phase at 82 ° C., and the phase transition from the smectic phase to the isotropic liquid phase at 82 ° C. A polymerizable liquid crystal composition (B) comprising 1 part by weight of a photopolymerization initiator "IRG-651" (manufactured by Ciba-Geigy) was prepared with respect to 100 parts by weight of the polymerizable liquid crystal composition (A). Next, a polyimide alignment film was formed, and two glass substrates that had been rubbed were made to face each other with an interval of 30 microns so that the surface of the polyimide alignment film faced inward, and the polymerizable liquid crystal composition (B ) Was pinched. The sandwiched polymerizable liquid crystal composition (B) was heated to 90 ° C. to make an isotropic liquid, and then cooled to 60 ° C. At this time, the polymerizable liquid crystal composition (B) was in a smectic liquid crystal state and was uniformly aligned.

Next, the polymerizable liquid crystal composition (B) was UV-rayed.
Using a lamp (UVGL-25, UVP), 50
The polymerizable liquid crystal composition was photopolymerized and cured by irradiation with ultraviolet light having a light amount of 0 mJ / cm ² . The photopolymerizable polymerizable liquid crystal composition sandwiched between the two glass substrates thus obtained was cooled to room temperature, and then the two glass substrates were peeled off to obtain a self-standing optical anisotropic body. . When X-ray analysis was performed on this optically anisotropic substance, a sharp diffraction peak derived from the layered structure of the liquid crystal molecular skeleton, which was characteristic of the smectic liquid crystal phase, was observed. As a result, it was confirmed that the alignment structure of the smectic liquid crystal phase was fixed in the optical anisotropic body, and the optical anisotropic body had a layered structure of the liquid crystal molecular skeleton inside. Moreover, the obtained optical anisotropic body was also excellent in heat resistance. (Example 2) Two glass substrates having a polyimide alignment film formed thereon and subjected to a rubbing treatment were made to face each other with an interval of 50 microns so that the surface of the polyimide alignment film faced the inside.
The polymerizable liquid crystal composition (B) obtained in Example 1 was sandwiched between the substrates. The sandwiched polymerizable liquid crystal composition (B) was heated to 90 ° C. to make an isotropic liquid, and then cooled to 25 ° C. At this time, the polymerizable liquid crystal composition (B) was in a supercooled smectic liquid crystal state and was uniformly aligned.

Next, the polymerizable liquid crystal composition (B) was exposed to UV.
Using a lamp (UVGL-25, UVP), 50
The polymerizable liquid crystal composition was photopolymerized and cured by irradiation with ultraviolet light having a light amount of 0 mJ / cm ² . 2 obtained in this way
After the photopolymerizable polymerizable liquid crystal composition sandwiched between the glass substrates was cooled to room temperature, the two glass substrates were peeled off to obtain a self-standing optical anisotropic body. When X-ray analysis was performed on this optically anisotropic substance, a sharp diffraction peak derived from the layered structure of the liquid crystal molecular skeleton, which was characteristic of the smectic liquid crystal phase, was observed. As a result, it was confirmed that the alignment structure of the smectic liquid crystal phase was fixed in the optical anisotropic body, and the optical anisotropic body had a layered structure of the liquid crystal molecular skeleton inside. Moreover, the obtained optical anisotropic body was also excellent in heat resistance.

(Embodiment 3) Formula (c)

[0050]

Embedded image

67 parts by weight of the compound of formula (r)

[0052]

[Chemical 21]

67 parts by weight of the compound of formula (s)

[0054]

[Chemical formula 22]

67 parts by weight of a polymerizable liquid crystal composition (C) was prepared. When this polymerizable liquid crystal composition (C) is heated to an isotropic liquid phase and then cooled, the phase changes from an isotropic liquid phase to a nematic phase at 97 ° C, and a phase change from a nematic phase to a smectic A phase at 45 ° C. did. From this, it is clear that this polymerizable liquid crystal composition exhibits a nematic phase at a temperature higher than that of the smectic A phase. A polymerizable liquid crystal composition (D) comprising 1 part by weight of a photopolymerization initiator "IRG-651" (manufactured by Ciba-Geigy) was prepared with respect to 200 parts by weight of the polymerizable liquid crystal composition (C). Next, a polyimide alignment film is formed, and two glass substrates that have been rubbed are made to face each other with an interval of 50 μm so that the surface of the polyimide alignment film faces inward to form an anti-parallel cell. The polymerizable liquid crystal composition (D) was sandwiched. The sandwiched polymerizable liquid crystal composition (D) is heated to 100 ° C. to be an isotropic liquid, and then 6
Cooled to 0 ° C. At this time, when the anti-parallel cell was observed with a polarizing microscope, the polymerizable liquid crystal composition (D) was in a nematic liquid crystal state and was uniformly uniaxially aligned. Then 40
When the antiparallel cell was observed with a polarizing microscope after cooling to 0 ° C., the polymerizable liquid crystal composition was in a smectic A liquid crystal state, and uniform uniaxial alignment was maintained. When the anti-parallel cell was observed with a polarizing microscope after cooling to room temperature, it was confirmed that the polymerizable liquid crystal composition was in a smectic A liquid crystal state, and uniform uniaxial alignment was maintained even at room temperature. In this state, a UV lamp (UVGL-25, manufactured by UVP) was used to irradiate the anti-parallel cell with ultraviolet light having a light amount of 500 mJ / cm ² to photopolymerize and cure the polymerizable liquid crystal composition. The photopolymerization product of the polymerizable liquid crystal composition sandwiched between the two glass substrates thus obtained was kept at 100 ° C. for 5 minutes, then immersed in water and rapidly cooled to remove the photopolymerization product from the photopolymerization product. The two glass substrates were peeled off. Observation of the photopolymerization product of the polymerizable liquid crystal composition separated from the glass substrate with a polarization microscope showed that a uniform uniaxial orientation state of the smectic A liquid crystal phase was fixed in the photopolymerization product, and thus an optically anisotropic substance was obtained. It was confirmed that was manufactured. In addition, the obtained optical anisotropic body was also excellent in heat resistance.

Example 4 Two glass substrates on which SiO ₂ was obliquely vapor-deposited so as to give a pretilt angle of 45 degrees,
An anti-parallel cell was prepared by facing the vapor-deposited surface so as to face each other at an interval of 100 microns, and the polymerizable liquid crystal composition (D) obtained in Example 3 was placed in the anti-parallel cell.
Was pinched. This sandwiched polymerizable liquid crystal composition (D)
Was heated to 100 ° C. to make an isotropic liquid, and then cooled to 60 ° C. At this time, when the anti-parallel cell was observed with a polarizing microscope, the polymerizable liquid crystal composition (D) was in a nematic liquid crystal state and was uniformly uniaxially aligned. Next, after cooling to 40 ° C., observation of the anti-parallel cell with a polarizing microscope revealed that the polymerizable liquid crystal composition was in a smectic A liquid crystal state, and uniform uniaxial alignment was maintained. When the anti-parallel cell was observed with a polarizing microscope after cooling to room temperature, it was confirmed that the polymerizable liquid crystal composition was in a smectic A liquid crystal state, and uniform uniaxial alignment was maintained even at room temperature. In this state, a UV lamp (UVGL-25, manufactured by UVP) was used to irradiate the anti-parallel cell with ultraviolet light having a light amount of 500 mJ / cm ² to photopolymerize and cure the polymerizable liquid crystal composition. The photopolymerization product of the polymerizable liquid crystal composition sandwiched between the two glass substrates thus obtained was kept at 100 ° C. for 5 minutes. After cooling to room temperature, the photopolymerization product of the polymerizable liquid crystal composition was observed with a polarization microscope. As a result, the uniform uniaxial alignment state of the smectic A liquid crystal phase was fixed in the photopolymerization product, and the optically anisotropic substance was observed. It was confirmed that was manufactured. In addition, the obtained optical anisotropic body was also excellent in heat resistance. This optically anisotropic body functioned as a polarization separation element. That is, when light is incident perpendicularly to the plane of the optical anisotropic body, the light emitted from the optical anisotropic body is separated into two polarizations orthogonal to each other, and one polarization is separated from the other polarization. It can be confirmed by observing with a microscope that the light is emitted from a position shifted by about 5 microns.

Example 5 A polyimide alignment film is formed,
Two glass substrates that were not subjected to rubbing treatment were made to face each other with an interval of 50 microns so that the surface of the polyimide alignment film faced inside, and a cell was prepared.
The polymerizable liquid crystal composition (D) obtained in the above was sandwiched. By heating the sandwiched polymerizable liquid crystal composition (D) to 100 ° C.,
After making it an isotropic liquid, this cell was left to stand in a magnetic field of 10 kG. At this time, the angle between the plane of the glass substrate and the magnetic field was set to 45 degrees. After cooling the cell, which has been left standing in a magnetic field, to room temperature, a UV lamp (UVP, UV
Using GL-25), the polymerizable liquid crystal composition was photopolymerized and cured by irradiating it with ultraviolet light having a light amount of 500 mJ / cm ² . The photopolymerization product of the polymerizable liquid crystal composition sandwiched between the two glass substrates thus obtained was kept at 100 ° C. for 5 minutes, then immersed in water and rapidly cooled to remove the photopolymerization product from the photopolymerization product. The two glass substrates were peeled off. Observation of the photopolymerization product of the polymerizable liquid crystal composition separated from the glass substrate with a polarization microscope showed that a uniform uniaxial orientation state of the smectic A liquid crystal phase was fixed in the photopolymerization product, and thus an optically anisotropic substance was obtained. It was confirmed that was manufactured. In addition, the obtained optical anisotropic body was also excellent in heat resistance. This optically anisotropic body functioned as a polarization separation element. That is, when light is incident perpendicularly to the plane of the optical anisotropic body, the light emitted from the optical anisotropic body is separated into two polarizations orthogonal to each other, and one polarization is separated from the other polarization. It was confirmed by microscopic observation that the light was emitted from a position displaced by about 2 microns.

[0058]

INDUSTRIAL APPLICABILITY The polymerizable liquid crystal composition of the present invention makes it easy to introduce optical biaxiality and to introduce a layered structure of a liquid crystal molecular skeleton therein when producing an optically anisotropic substance. is there. The obtained optically anisotropic substance is excellent in the uniformity of the orientation structure of the molecules inside and the heat resistance.

Therefore, the polymerizable liquid crystal composition of the present invention is very useful as a material for an optical compensation plate of a liquid crystal display element, a polarizing prism, and a novel optical element.

Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location // C08F 20/18 MLY C08F 20/18 MLY

Claims (17)

[Claims] 1. A monofunctional (meth) acrylate compound which is a (meth) acrylic acid ester of a cyclic alcohol, a phenol or an aromatic hydroxy compound having a liquid crystalline skeleton having at least two 6-membered rings as a partial structure, A polymerizable liquid crystal composition having a smectic liquid crystal phase. 2. The polymerizable liquid crystal composition according to claim 1, wherein the smectic liquid crystal phase is a smectic A liquid crystal phase. 3. Smectic A in order from low temperature side to high temperature side
The polymerizable liquid crystal composition according to claim 2, which exhibits a phase sequence of phase-nematic phase-isotropic liquid phase. 4. Smectic A in order from the low temperature side to the high temperature side
The polymerizable liquid crystal composition according to claim 3, further comprising a monofunctional (meth) acrylate exhibiting a phase sequence of phase-nematic phase-isotropic liquid phase. 5. The polymerizable liquid crystal composition according to claim 3, which exhibits a smectic A liquid crystal phase at room temperature. 6. A monofunctional (meth) acrylate compound,
General formula (I) (In the formula, X represents a hydrogen atom or a methyl group, and the 6-membered rings A, B and C are independently, , N is an integer of 0 or 1, and m is 1 to 4
In which Y ¹ and Y ² are each independently a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —C.
OO-, -OCO-, -C≡C-, -CH = CH-,-
CF = CF -, - (CH 2) 4 -, - CH 2 CH 2 CH 2 O
_{-, - OCH 2 CH 2 CH} 2 -, - CH 2 = CHCH 2 CH 2
- or -CH ₂ CH ₂ CH = CH- and represents, Y ³ represents a single bond, -COO -, - OCO- represents, R represents a hydrogen atom,
It represents a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxy group, an alkenyl group or an alkenyloxy group. The polymerizable liquid crystal composition according to claim 1, which is a compound represented by the formula (1). 7. A monofunctional (meth) acrylate compound,
General formula (I): (In the formula, X represents a hydrogen atom or a methyl group, and the 6-membered rings A, B and C are independently, , N is an integer of 0 or 1, and m is 1 to 4
In which Y ¹ and Y ² are each independently a single bond, —CH ₂ CH ₂ —, —CH ₂ O—, —OCH ₂ —, —C.
OO-, -OCO-, -C≡C-, -CH = CH-,-
CF = CF -, - (CH 2) 4 -, - CH 2 CH 2 CH 2 O
_{-, - OCH 2 CH 2 CH} 2 -, - CH 2 = CHCH 2 CH 2
- or -CH ₂ CH ₂ CH = CH- and represents, Y ³ represents a single bond, -COO -, - OCO- represents, R represents a hydrogen atom,
It represents a halogen atom, a cyano group, an alkyl group having 1 to 20 carbon atoms, an alkoxy group, an alkenyl group or an alkenyloxy group. 6. The polymerizable liquid crystal composition according to claim 2, which is a compound represented by the formula: 8. In the general formula (I), the 6-membered rings A, B and C are each independently And m represents an integer of 1 or 2, Y ¹ and Y ² each independently represent a single bond or —C≡C—, and R represents a halogen atom, a cyano group, or an alkyl group having 1 to 20 carbon atoms. The polymerizable liquid crystal composition according to claim 6, which is a group, an alkoxyl group or an alkenyl group. 9. In the general formula (I), at least one ring of the 6-membered rings A, B and C is Wherein m represents an integer of 1 or 2, Y ¹ , Y ² and Y ³ represent a single bond, and R represents an alkyl group having 1 to 20 carbon atoms. Polymerizable liquid crystal composition. 10. A compound represented by the general formula (II): 8. In the formula, X ¹ represents a hydrogen atom or a methyl group, and R ¹ represents an alkyl group having 1 to 18 carbon atoms. 9. The polymerizable liquid crystal composition according to item 9. 11. A compound represented by the general formula (II): (In the formula, X ¹ represents a hydrogen atom or a methyl group, R ¹ represents an alkyl group having 1 to 18 carbon atoms) and the general formula (III): Wherein X ² represents a hydrogen atom or a methyl group, R ² represents an alkyl group or an alkoxy group having 1 to 18 carbon atoms, and a monofunctional (meth) acrylate is contained. Item 10. The polymerizable liquid crystal composition according to item 7 or 9. 12. A compound represented by the general formula (IV): (In the formula, X ³ represents a hydrogen atom or a methyl group, X ⁴ represents a hydrogen atom or a fluorine atom, and R ³ represents 1 to 1 carbon atoms.
Represents 18 alkyl groups. 12. The polymerizable liquid crystal composition according to claim 7, 9, 10 or 11, which comprises the monofunctional acrylate or monofunctional methacrylate compound of 4). 13. A polymerizable liquid crystal composition exhibiting a smectic liquid crystal phase, which further comprises a chiral compound in addition to the monofunctional (meth) acrylate according to claim 1, 6 or 8. 14. Photopolymerization by irradiating the polymerizable liquid crystal composition according to claim 1, 6, 8 or 13 with ultraviolet rays or electron beams in a state where the polymerizable liquid crystal composition is aligned in a smectic liquid crystal phase. And a method for producing an optically anisotropic body. 15. An optical anisotropic body obtained by the manufacturing method according to claim 13. 16. Claims 2, 3, 4, 5, 7, 9, 1
An optical anisotropic body characterized in that the polymerizable liquid crystal composition according to 0, 11, or 12 is irradiated with ultraviolet rays or electron beams to the polymerizable liquid crystal composition for photopolymerization in a state in which the polymerizable liquid crystal composition is aligned in a smectic A liquid crystal phase. Manufacturing method. 17. An optical anisotropic body obtained by the manufacturing method according to claim 16.