CN111918951A

CN111918951A - Liquid crystal composition, monomer/liquid crystal mixture, polymer/liquid crystal composite material, liquid crystal element and chiral compound

Info

Publication number: CN111918951A
Application number: CN201980021391.6A
Authority: CN
Inventors: 佐郷弘毅; 山本真一; 藤田浩章
Original assignee: JNC Corp; JNC Petrochemical Corp
Current assignee: JNC Corp; JNC Petrochemical Corp
Priority date: 2018-04-10
Filing date: 2019-03-15
Publication date: 2020-11-10
Also published as: TW201943842A; JP7248021B2; WO2019198422A1; JPWO2019198422A1

Abstract

The present invention provides a liquid crystal composition containing at least one of chiral compounds represented by formula (K1) as a chiral component (K) and at least one of achiral compounds represented by formula (1-A) or formula (1-B) as an achiral component (T). Chiral component (K)

Achiral Components (T)

Description

Liquid crystal composition, monomer/liquid crystal mixture, polymer/liquid crystal composite material, liquid crystal element and chiral compound

Technical Field

The invention relates to a liquid crystal composition containing a chiral component and an achiral component, a monomer/liquid crystal mixture, a polymer/liquid crystal composite material, a liquid crystal element and a chiral compound.

Background

As a technique for achieving low-voltage driving, which is an important characteristic required for practical use of a light scattering liquid crystal display device, a light control layer using a chiral nematic liquid crystal composition containing a liquid crystal composition, a chiral compound, and a photopolymerizable monomer is disclosed (patent documents 1 to 3). A light control layer produced by photopolymerizing a photopolymerizable monomer contained in a chiral nematic liquid crystal composition in the presence of a polymerization initiator is used in a low-voltage-driven liquid crystal device. Specifically, the present invention is used for a light control window for electrically operating a liquid crystal device capable of blocking or transmitting external light or a field of view, particularly, a window of a building, a shop window, an indoor partition (partition), a roof window of a vehicle, a rear window, or the like, to block or transmit external light or a field of view.

Similarly to an isotropic phase (hereinafter, sometimes referred to as a "non-liquid crystal isotropic phase") in a nematic liquid crystal material, a Kerr effect (Δ n (E) ═ K λ E) is observed in a blue phase which is one of optically isotropic liquid crystal phases²(K: Kerr coefficient (Kerr constant), lambda: wavelength)]The kerr effect is a phenomenon in which an electric birefringence value (a birefringence value excited when an electric field is applied to an isotropic medium) Δ n (E) is proportional to the square of the electric field E. Further, a mode in which an electric field is applied to an optically isotropic liquid crystal phase such as a blue phase and a polymer-stabilized blue phase to express an electro birefringence is disclosed (patent documents 4 to 9, and non-patent documents 1 to 3). As for the blue phase, not only applications to the display element of the above-described mode, but also applications to a tunable filter (tunable filter) using electro birefringence, a wavefront control (wave front control) element, a liquid crystal lens, an aberration correction element, an aperture control element, an optical head device, and the like have been proposed (patent documents 7 to 9).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 5-241119

Patent document 2: japanese patent laid-open No. 5-281525

Patent document 3: japanese patent laid-open No. 5-289064

Patent document 4: japanese patent laid-open No. 2003-327966

Patent document 5: international publication No. 2005/90520

Patent document 6: japanese patent laid-open No. 2005-336477

Patent document 7: international publication No. 2005/080529

Patent document 8: japanese patent laid-open publication No. 2005-157109

Patent document 9: japanese patent laid-open No. 2006-127707

Non-patent document

Non-patent document 1: book of Natural Materials (Nature Materials) No. 1, page 64 (2002)

Non-patent document 2: advanced Materials, adv. mater, 17 th page 96 (2005)

Non-patent document 3: international Society for Information Display (Journal of the Society for Information Display, Journal of the SID) 14, page 551 (2006)

Non-patent document 4: soft Material (Soft Matter) No. 10, page 6582 (2014)

Disclosure of Invention

Problems to be solved by the invention

Liquid crystal compositions exhibiting a chiral nematic phase, or an optically isotropic phase, contain chiral and achiral components. In general, the larger the Helical Twisting Power (HTP) of the chiral compound, the shorter the helical pitch of the liquid crystal can be by adding a smaller amount of the chiral compound to the liquid crystal composition. Therefore, a liquid crystal composition having a target helical pitch can be realized by the addition of a small amount of a chiral compound. In addition, in the case of using the liquid crystal composition for optical isotropy, a chiral nematic phase or an optically isotropic phase is expressed by adding a small amount of the chiral compound, and in the case of using the liquid crystal composition as a liquid crystal element, effects such as reduction of driving voltage and suppression of precipitation of the chiral compound can be expected. The reason for this is that: in the liquid crystal composition, components contributing to characteristics of the liquid crystal element such as a driving voltage and a response speed are achiral components, and the content of the achiral components can be increased by using a chiral compound having a large HTP. In addition, a chiral compound having good compatibility can improve the compatibility of the liquid crystal composition, and when the chiral compound is used as a liquid crystal element, the liquid crystal composition can be driven over a wide temperature range including a low temperature. In addition, when the liquid crystal composition is prepared, the time required for dissolution can be greatly shortened, so that efficient production can be realized and the production cost can be reduced.

Accordingly, an object of the present invention is to provide a liquid crystal composition and a liquid crystal device which contain a chiral component and an achiral component having a large Helical Twist Power (HTP), good compatibility with other liquid crystal compounds, and good reliability such as light resistance, and which have a low driving voltage, a high-speed response, and good storage stability. Also disclosed are a liquid crystal composition and a liquid crystal element which are stable against external light and have excellent light resistance and which can be used for a long period of time on the outside.

Means for solving the problems

The present inventors have made extensive studies and, as a result, have found that the above problems can be solved by using the following liquid crystal composition: the liquid crystal composition uses a 9,10-ethanoanthracene (9, 10-ethanoanthrylene) chiral compound as a chiral component, and uses a fluorine-based liquid crystal compound as an achiral component. Specifically, the following is described.

[1] A liquid crystal composition containing at least one of chiral compounds represented by formula (K1) as a chiral component (K) and at least one of achiral compounds represented by formula (1-A) or formula (1-B) as an achiral component (T).

[ solution 1]

Chiral component (K)

(in the formula (K1),

R^k1independently represents fluorine, chlorine, -C ≡ N, C1-10 alkyl, or C2-10 alkenyl, wherein at least one-CH group in the alkyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen;

Y^k1each independently is a single bond, or- (CH)₂)_n-, n is an integer of 1 to 20;

nk1 and nk2 are each independently an integer of 0 to 4,

Rod^k1is part of the structural formula (Rod1),

in the partial structural formula (Rod1),

R^k2hydrogen, fluorine, chlorine, -C ≡ N, C1-10 alkyl, and C2-10 alkenyl, wherein at least one-CH in the alkyl₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen;

ring A^k1Ring A^k2And ring A^k3Each independently is 1, 4-cyclohexylene, 1, 4-phenylene in which at least one hydrogen is substituted with fluorine, 1, 3-dioxane-2, 5-diyl, tetrahydropyran-2, 5-diyl, or pyrimidine-2, 5-diyl;

Z^k1、Z^k2and Z^k3Each independently is a single bond, -CH₂CH₂-、-COO-、-OCO-、-OCH₂-、-CH₂O-、-CF₂O-、-OCF₂-、-CH＝CH-、-CF₂CF₂-, -CF ═ CF-, or-C ≡ C-;

mk1 and mk2 are each independently an integer of 0 or 1;

in addition, 0 to 4R are connected in the ring structure shown below^k1In the partial structure (X1) and the partial structure (X2), 0 to 4 hydrogens of the hydrogens forming the ring structure can be replaced by R^k1Substituted)

[ solution 2]

[ solution 3]

Achiral component (T)

(in the formulae (1-A) and (1-B),

R¹¹and R¹²Independently represents hydrogen, alkyl group having 1 to 10 carbon atoms, alkoxy group having 1 to 10 carbon atoms or alkoxy group having 2 to 10 carbon atomsAlkenyl, in the alkyl and alkenyl, at least one-CH₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen;

ring A¹¹Ring A¹²And ring A¹³Each independently is 1, 4-cyclohexylene, 1, 4-phenylene in which at least one hydrogen is substituted with fluorine, 1, 3-dioxane-2, 5-diyl, tetrahydropyran-2, 5-diyl, or pyrimidine-2, 5-diyl;

Z¹¹、Z¹²and Z¹³Each independently is a single bond, -CH₂CH₂-、-COO-、-OCO-、-CH₂O-、-OCH₂-、-CF₂O-、-OCF₂-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-;

X¹¹is fluorine, chlorine, -SF₅、-CHF₂、-CF₃、-CF₂CH₂F、-CF₂CHF₂、-CF₂CF₃、-(CF₂)₃-F、-CF₂CHFCF₃、-CHFCF₂CF₃、-(CF₂)₄-F、-(CF₂)₅-F、-OCHF₂、-OCF₃、-OCF₂CH₂F、-OCF₂CHF₂、-OCH₂CF₃、-OCF₂CF₃、-O-(CF₂)₃-F、-OCF₂CHFCF₃、-OCHFCF₂CF₃、-O-(CF₂)₄-F、-O-(CF₂)₅-F、-CH＝CF₂、-CH＝CHCF₃or-CH ═ CHCF₂CF₃；

L¹¹And L¹²Each independently is hydrogen or fluorine;

L¹³and L¹⁴Each independently hydrogen, fluorine, chlorine, or-C ≡ N, except that L¹³And L¹⁴Will not all be hydrogen;

S¹¹is hydrogen or methyl;

m and n are each independently 0 or 1)

[2] The liquid crystal composition according to [1], wherein the chiral compound represented by the formula (K1) is a chiral compound represented by the formula (K1-1).

[ solution 4]

(in the formula (K1-1),

R^k1each independently represents fluorine, chlorine, -C ≡ N, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, wherein at least one-CH group in the alkyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen;

nk1 and nk2 are each independently an integer of 0 to 4,

Rod^k1is partial structural formula (Rod1-1) or partial structural formula (Rod1-2),

in the partial structural formula (Rod1-1) and the partial structural formula (Rod1-2),

R^k2is hydrogen, fluorine, chlorine, -C ≡ N, alkyl with 1-10 carbon atoms, or alkenyl with 2-10 carbon atoms, wherein at least one-CH in the alkyl₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen;

Z^k2and Z^k3Each independently is a single bond, -CH₂CH₂-、-COO-、-OCO-、-OCH₂-、-CH₂O-、-CF₂O-、-OCF₂-、-CH＝CH-、-CF₂CF₂-, -CF ═ CF-, or-C ≡ C-;

mk1 and mk2 are each independently an integer of 0 or 1;

r is bonded to a ring structure shown below^k1Partial structure (X1) and partial structure(X2) 0 to 4 hydrogens of the hydrogens forming the ring structure can be replaced by R^k1Substituted)

[ solution 5]

[3] The liquid crystal composition according to [2], wherein in the formula (K1-1),

R^k1each independently represents an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, wherein at least one-CH group is present in the alkyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen;

nk1 and nk2 are each independently an integer of 0 to 4,

Rod^k1is any of the following partial structural formulae (Rod1-1A) to (Rod1-1H) and (Rod1-2A) to (Rod 1-2H).

[ solution 6]

[ solution 7]

(partial structural formula (Rod1-1A) partial structural formula (Rod1-1H) and partial structural formula (Rod1-2A) partial structural formula (Rod1-2H),

R^k2is hydrogen, alkyl group having 1 to 10 carbon atoms, or alkenyl group having 2 to 10 carbon atoms, at least one-CH in the alkyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen;

further, the partial structure (X3) shown below in which (F) is bonded to a1, 4-phenylene group represents a1, 4-phenylene group in which one or two hydrogens may be substituted with fluorine

[ solution 8]

[4] The liquid crystal composition according to any one of [1] to [3], wherein the achiral compound represented by the formula (1-A) is any one of achiral compounds represented by the formulae (1-A-01) to (1-A-22).

[ solution 9]

[ solution 10]

[ solution 11]

In the formulae (1-A-01) to (1-A-22),

R¹¹independently an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, at least one-CH group being present in the alkyl group and the alkenyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-;

ring A¹¹And ring A¹²Independently 1, 4-cyclohexylene, or tetrahydropyran-2, 5-diyl, or pyrimidine-2, 5-diyl;

X¹¹independently of one another, fluorine, chlorine, -CF₃or-OCF₃；

(F) Is hydrogen or fluorine.

[5] The liquid crystal composition according to any one of [1] to [3], wherein the achiral compound represented by the formula (1-B) is any one of achiral compounds represented by the formulae (1-B-01) to (1-B-22).

[ solution 12]

[ solution 13]

In the formulae (1-B-01) to (1-B-22),

R¹¹and R¹²Independently an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms, at least one-CH group being present in the alkyl group and the alkenyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-;

(F) is hydrogen or fluorine.

[6] The liquid crystal composition according to any one of [1] to [5], wherein the content of the chiral component (K) in the liquid crystal composition is 0.1 to 30% by weight.

[7] The liquid crystal composition according to any one of [1] to [6], wherein the content of the compound represented by the formula (1-A) or the formula (1-B) in the achiral component (T) is 50 to 100% by weight.

[8] The liquid crystal composition according to any one of [1] to [6], wherein the content of the compound represented by formula (1-A) in the achiral component (T) is 50% by weight to 100% by weight, and shows an optically isotropic liquid crystal phase.

[9] The liquid crystal composition according to any one of [1] to [8], wherein the chiral component (K) further contains at least one chiral compound represented by formula (K2) to formula (K8).

[ solution 14]

In the formulae (K2) to (K8), R^KEach independently represents hydrogen, halogen, -C ≡ N, -N ═ C ═ O, -N ═ C ═ S, or alkyl having 1 to 20 carbon atoms, and at least one-CH group in the alkyl groups₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by halogen;

A^Keach independently an aromatic 6-to 8-membered ring, a non-aromatic 3-to 8-membered ring, or a condensed ring having 9 to 20 carbon atoms, at least one of these rings being substituted with a halogen, an alkyl group having 1 to 3 carbon atoms or a haloalkyl group, or a-CH group₂-may be substituted by-O-, -S-or-NH-CH-may be substituted by-N;

Y^Keach independently hydrogen, halogen, alkyl having 1 to 3 carbon atoms, haloalkyl having 1 to 3 carbon atoms, aromatic 6-to 8-membered ring, non-aromatic 3-to 8-membered ring, or condensed ring having 9 to 20 carbon atoms, wherein at least one hydrogen of these rings is substituted by halogen, alkyl having 1 to 3 carbon atoms or haloalkyl, -CH₂-may be substituted by-O-, -S-or-NH-CH-may be substituted by-N;

Z^Keach independently a single bond or an alkylene group having 1 to 8 carbon atoms, but at least one-CH₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N ═ N-, -CH ═ N-, -N ═ CH-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, at least one hydrogen being substituted by halogen;

X^Keach independently is a single bond, -COO-, -OCO-, -CH₂O-、-OCH₂-、-CF₂O-、-OCF₂-, or-CH₂CH₂-；

mK is an integer of 1 to 4 independently

[10] A monomer/liquid crystal mixture comprising the liquid crystal composition according to any one of [1] to [9], and a polymerizable monomer.

[11] The monomer/liquid crystal mixture according to [10], which exhibits a chiral nematic phase in a temperature range of at least 1 ℃ or more at-20 ℃ to 70 ℃ and has a helical pitch of 700nm or less in at least a part of the temperature range.

[12] The monomer/liquid crystal mixture according to [10], wherein the liquid crystal composition is a liquid crystal composition having an optically isotropic liquid crystal phase.

[13] The monomer/liquid crystal mixture according to any one of [10] to [12], wherein the content of the polymerizable monomer is in the range of 0.1 to 50% by weight with respect to the total amount of the monomer/liquid crystal mixture.

[14] A polymer/liquid crystal composite material which is obtained by polymerizing the monomer/liquid crystal mixture according to [10] in a non-liquid crystal isotropic phase or an optically isotropic liquid crystal phase and which is used for a liquid crystal cell driven in the optically isotropic liquid crystal phase.

[15] A polymer/liquid crystal composite material which is obtained by polymerizing the monomer/liquid crystal mixture according to [10] and is used for a light scattering type liquid crystal element driven by a chiral nematic phase.

[16] A liquid crystal cell comprising: a pair of substrates having electrodes; a light adjusting layer sandwiched between the pair of substrates; and an electric field applying member for applying an electric field to the dimming layer via the electrode,

at least one of the pair of substrates is transparent, and the dimming layer comprises the polymer/liquid crystal composite material according to [14] or [15 ].

[17] The liquid crystal element according to [16], wherein the polymer/liquid crystal composite exhibits a chiral nematic phase and constitutes a light scattering type liquid crystal element.

[18] The liquid crystal element according to [16] or [17], wherein the content of the polymer in the polymer/liquid crystal composite material is in a range of 0.1 to 50% by weight.

[19] A chiral compound is represented by the following formula (K101), formula (K102), or formula (K103).

[ solution 15]

Here, (R) represents a palm character.

In the present specification, the term "liquid crystal compound" is a generic term for compounds having a liquid crystal phase such as a nematic phase or a smectic phase and compounds which do not have a liquid crystal phase but can be used as a component of a liquid crystal composition. The liquid crystal compound, the liquid crystal composition, and the liquid crystal display element may be simply referred to as a compound, a composition, or an element, respectively.

In this specification, the term "liquid crystal element" is a generic term for a liquid crystal display panel and a liquid crystal display module. The upper limit temperature of the nematic phase is the phase transition temperature of the nematic phase-isotropic phase, and is sometimes simply referred to as the clearing point or upper limit temperature. The lower limit temperature of the nematic phase is sometimes simply referred to as the lower limit temperature.

In the present specification, the compound represented by formula (1) may be simply referred to as compound (1). The above-mentioned abbreviations may be applied to the compounds represented by the formula (2) and the like. In the formula, A is surrounded by a hexagon¹¹、A¹²The marks are respectively connected with the ring structures A¹¹Ring structure A¹²Etc. correspond to each other.

These are sometimes referred to simply as "Ring A¹¹"," Ring A¹²". The "ring structure" refers to a cyclic group including a benzene ring, a naphthalene ring, a cyclohexene ring, a bicyclooctane ring, a cyclohexane ring, or the like. Here, the number of the ring structures including a plurality of rings such as a condensed polycyclic hydrocarbon such as a naphthalene ring and a bridged cyclic hydrocarbon such as a bicyclooctane ring is also 1 as the ring structure.

Although it is cyclic A^k1Ring Y^k1A plurality of the same symbols are described in the same formula or different formulae, but these symbols may be the same or different.

The wavy line in the formula represents a bonding site.

"at least one" is not limited to a position and a number, but does not include the case where the number is 0. The expression that at least one A may be substituted by B, C or D means that in addition to the case where at least one A is substituted by B, the case where at least one A is substituted by C and the case where at least one A is substituted by D, a plurality of A's are also included by B to DAt least two substitutions. For example at least one-CH₂Among the alkyl groups which may be substituted by-O-or-CH ═ CH-, include alkyl, alkenyl, alkoxy, alkoxyalkyl, alkoxyalkenyl, alkenyloxyalkyl and the like. Further, in the present invention, two-CHs are consecutive₂The case where-O-is substituted with-O-is not preferable. Furthermore, the terminal-CH group in the alkyl group₂The case of-O-substitution is also less preferred.

In the present specification, "%" means "% by weight" unless otherwise specified.

Effects of the invention

The liquid crystal composition containing a chiral component and an achiral component according to the embodiment of the present invention is preferably used for liquid crystal cell applications because of its good light resistance. The chiral compound according to the embodiment of the present invention has a high HTP and high compatibility with an achiral component, and thus can be adjusted to a pitch of 0.5 μm or less. In addition, the liquid crystal phase can be displayed in a wide temperature range including a low temperature.

Further, since the liquid crystal element obtained using the liquid crystal composition is driven at a low voltage and the light scattering changes greatly between when a voltage is applied and when no voltage is applied, the liquid crystal composition can be suitably used for a liquid crystal device exhibiting a high contrast.

In order to more favorably bring out the performance of the liquid crystal composition according to the embodiment of the present invention, it is preferable to use a chiral nematic liquid crystal or a cholesteric liquid crystal in combination. In the liquid crystal composition according to the embodiment of the present invention, in addition to the chiral compound represented by the formula (K1), a material generally recognized as a liquid crystal material in the technical field, a chiral compound other than the chiral compound represented by the formula (K1), and the like may be further added and used as appropriate.

In addition, an optically isotropic liquid crystal composition can be efficiently produced in a short time. The liquid crystal composition, the liquid crystal composition exhibiting an optically isotropic liquid crystal phase, and the polymer/liquid crystal composite material according to the embodiments of the present invention exhibit a relatively large kerr coefficient. I.e. shows a relatively low driving voltage. The liquid crystal composition and the polymer/liquid crystal composite material according to the embodiment of the present invention, which exhibit optical isotropy, have a high response speed.

The liquid crystal composition and the polymer/liquid crystal composite material exhibiting an optically isotropic liquid crystal phase according to the embodiments of the present invention can be used in a wide temperature range. Further, the liquid crystal composition and the polymer/liquid crystal composite material exhibiting an optically isotropic liquid crystal phase according to the embodiment of the present invention can be preferably used for a liquid crystal device such as a liquid crystal display device for high-speed response applications, based on these effects.

Drawings

Fig. 1 shows a comb-shaped electrode substrate used in the examples.

Fig. 2 shows an optical system used in the embodiment.

Fig. 3 is a cross section showing an example of the structure of the liquid crystal element.

Fig. 4 is a cross section showing another example of the structure of the liquid crystal element.

Detailed Description

1. Liquid crystal composition of the invention

The first embodiment of the present invention is a liquid crystal composition that can be used in a liquid crystal cell driven in a chiral nematic phase or an optically isotropic phase.

The liquid crystal composition of the embodiment of the present invention has a compound represented by formula (K1) as a chiral component, and has an achiral component. Here, the chiral component is not limited. The liquid crystal composition according to the embodiment of the present invention preferably exhibits a chiral nematic phase or an optically isotropic phase.

The compound contained in the liquid crystal composition according to the embodiment of the present invention is generally synthesized by a conventional method, for example, a method of reacting necessary components at a high temperature.

In addition, each element constituting the compound of the liquid crystal composition of the embodiment of the present invention may be used as long as there is no large difference in physical properties even if it is an analog containing an isotope element.

In the liquid crystal composition of the embodiment of the present invention, the content of the chiral component (K) is usually 0.1 to 30% by weight, preferably 0.1 to 10% by weight.

1.1 chiral nematic phase

The liquid crystal composition of the embodiment of the invention includes a liquid crystal composition having a chiral nematic phase. The chiral nematic phase can be obtained by adding a small amount of a chiral compound to the achiral component comprising the compound exhibiting the nematic phase. In order to obtain a sufficient contrast between opacity and transparency due to light scattering, the liquid crystal composition used in the embodiment of the present invention preferably has a helical pitch (hereinafter, sometimes simply referred to as "pitch") of 0.3 to 5 μm. Generally, the transparency by light scattering is relatively high in the range of 0.3 μm to 0.5 μm of the helical pitch, and the opacity by light scattering is relatively high in the range of 0.6 μm to 5 μm of the helical pitch.

For use in light control materials, compound (K1) has a high HTP value and high compatibility with compound (1-A) or compound (1-B), and therefore, the pitch of 0.5 μm or less can be adjusted. Further, since effective light scattering property can be obtained and stability with respect to light is high, a liquid crystal element which can obtain high contrast and high light resistance by low voltage driving can be provided.

1.2 optically isotropic liquid-crystalline phase

The liquid crystal composition according to the embodiment of the present invention includes a liquid crystal composition having an optically isotropic liquid crystal phase. Here, the term "liquid crystal composition having optical isotropy" means that liquid crystal molecules are arranged isotropically in a macroscopic view, and thus exhibit optical isotropy, but liquid crystal order is present in a microscopic view.

In the present specification, the "optically isotropic liquid crystal phase" refers to a phase that does not exhibit fluctuation but exhibits optically isotropic liquid crystal phase, and for example, a phase that exhibits platelet (platelet) structure (blue phase in a narrow sense) is an example thereof.

In general, blue phases are classified into three (blue phase I, blue phase II, blue phase III), all of which are optically active and isotropic. Two or more diffracted lights due to Bragg reflection (Bragg reflection) from different lattice planes are observed in the blue phase of the blue phase I or the blue phase II.

In the liquid crystal composition according to the embodiment of the present invention, in order to exhibit an optically isotropic liquid crystal phase, the helical pitch based on the liquid crystal order in microscopic view is preferably 1000nm or less.

Since the longer the pitch, the larger the electric birefringence in the optically isotropic liquid crystal phase, the larger the electric birefringence can be set by adjusting the type and content of the chiral component and setting the pitch to be long, as long as desired optical characteristics (transmittance, diffraction wavelength, and the like) are satisfied.

In the present specification, the "non-liquid crystal isotropic phase" is an isotropic phase generally defined as a disordered phase, and is an isotropic phase whose cause depends on fluctuation even if a region having a local order parameter not equal to zero is generated. For example, an isotropic phase exhibited on the high temperature side of a nematic phase corresponds to a non-liquid crystal isotropic phase in the present specification. The same definition applies to the chiral liquid crystal compound in the present specification.

1.3 chiral component (K)

1.3.1 Properties of chiral Compound (K1)

The chiral component (K) contained in the liquid crystal composition according to the embodiment of the present invention includes a compound represented by the following formula (K1).

[ solution 16]

In the formula (K1), the compound,

R^k1each independently represents fluorine, chlorine, -C ≡ N, an alkyl group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, wherein at least one-CH group in the alkyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen.

Preferred examples thereof include hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, an alkenyl group having 2 to 5 carbon atoms and an alkoxy group having 1 to 5 carbon atoms.

Y^k1Each independently is a single bond,Or- (CH)₂)_nN is an integer of 1 to 20.

Preferred examples are single bonds, -CH₂CH₂-、-(CH₂)₄-, or- (CH)₂)₆When n is small, HTP is large, and when n is large, compatibility tends to be good.

nk1 and nk2 are each independently an integer of 0 to 4.

The preferred examples are 0, 1 or 2, and when nk1 is 1 or 2, the compatibility in the liquid crystal composition tends to be good.

Rod^k1Is part of the structural formula (Rod1),

in the partial structural formula (Rod1),

R^k2is hydrogen, fluorine, chlorine, -C ≡ N, alkyl with 1-10 carbon atoms, or alkenyl with 2-10 carbon atoms, wherein at least one-CH in the alkyl₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen.

Preferred examples thereof include an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 7 carbon atoms, and an alkoxy group having 1 to 7 carbon atoms.

Further, as the partial structural formula, (Rod1-1) or (Rod1-2) is preferable, and in the case of (Rod1-1), HTP is high, and in the case of (Rod1-2), compatibility in the liquid crystal composition is relatively good.

Ring A^k1Ring A^k2And ring A^k3Each independently is 1, 4-cyclohexylene, 1, 4-phenylene in which at least one hydrogen is substituted by fluorine, 1, 3-dioxane-2, 5-diyl, tetrahydropyran-2, 5-diyl, or pyrimidine-2, 5-diyl.

Preferred examples are 1, 4-cyclohexylene, 1, 4-phenylene in which one or both hydrogens are substituted with fluorine, or 1, 3-dioxane-2, 5-diyl, and the HTP of the compound is large and the compatibility in other liquid crystal compositions is good.

Z^k1、Z^k2And Z^k3Each independently is a single bond, -CH₂CH₂-、-COO-、-OCO-、-OCH₂-、-CH₂O-、-CF₂O-、-OCF₂-、-CH＝CH-、-CF₂CF₂-、-CF ═ CF-, or-C ≡ C-;

preferred examples thereof include a single bond, -COO-, -OCO-, an alkylene group having 1 to 10 carbon atoms, -CH₂O-、-OCH₂-、-CF₂O-, or-OCF₂-. In the case of these substituents, the balance between HTP and compatibility in the liquid crystal composition becomes good.

mk1 and mk2 are each independently an integer of 0 or 1.

The compound having the value of mk1+ mk2 of 1 is excellent in compatibility in the liquid crystal composition. Further, the compound having mk1+ mk2 of 2 tends to have a large HTP.

In the presence of a plurality of R^k1、R^k2、A^k1、Z^k1The same or different symbols may be used for nk1, nk2, and the like.

Furthermore, the alkyl group having 1 to 10 carbon atoms is more preferably an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group include, but are not limited to, methyl, ethyl, propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, pentyl, hexyl, and dodecyl.

Preferred examples of the chiral compound represented by the formula (K1) are compounds represented by the formula (K1-1), and Rod^k1In the formula (K1-1), Rod1-1 is more preferable^k1And (Rod1-1C), (Rod1-1D), (Rod1-1F), and (Rod 1-1G). Both of them have high HTP and are relatively compatible with the liquid crystal composition.

In general, the content of the chiral component in the liquid crystal composition according to the embodiment of the present invention is preferably 0.1 to 20% by weight, and particularly preferably 1 to 10% by weight. Liquid crystal compositions containing a chiral component in these ranges tend to have an optically isotropic liquid crystal phase.

By using the liquid crystal composition of the embodiment of the present invention, a polymer/liquid crystal composite material described later can be obtained. When the polymer/liquid crystal composite material is used as a light control material, the helical pitch in the liquid crystal composition is particularly preferably in the range of 0.3 to 0.5 μm and 0.6 to 5 μm in order to obtain a sufficient contrast between opacity and transparency due to light scattering.

When the liquid crystal composition according to the embodiment of the present invention is used in a liquid crystal display device, it is preferable that the concentration of the chiral component is adjusted so that diffraction or reflection is not substantially observed in the visible region.

The chiral compound constituting the chiral component contained in the liquid crystal composition according to the embodiment of the present invention may be one kind, or two or more kinds.

In the case where two or more chiral compounds are used, it is preferable to use chiral compounds having the same twist direction so as not to cancel HTP. Chiral compounds with opposite twist directions can also be used in combination for the purpose of adjusting the temperature dependence of the helical pitch.

1.3.2 Synthesis of chiral Compound (K1)

Next, the synthesis of the compound represented by formula (K1) will be described. Compound (K1) can be synthesized by appropriately combining the methods in organic synthetic chemistry. Methods for introducing the desired end groups, rings and bonding groups into the starting materials are described in: organic Synthesis (Organic Synthesis, John Wiley's parent publishing company (John Wiley & Sons, Inc.)), (Organic Reactions, John Wiley & Sons, Inc.), [ Organic Synthesis (Comprehensive Organic Synthesis, Pegman publishing company (Pergamon Press)), New Experimental chemistry lecture (Bolus), and the like.

There are various methods for synthesizing the compound (K1), and it can be synthesized appropriately by referring to examples or books of the present specification.

First, an example of a method for producing the compound (15) as a common intermediate will be described with reference to a flowchart.

(1) Preparation and Synthesis of Anthracene derivative (15)

[ solution 17]

The anthracene derivative can be synthesized from a commercially available compound by a general organic synthesis method. Examples of commercially available compounds include compound (ref.001) and compound (ref.002).

At R^k1In the case of an alkyl group, an alkenyl group, an alkynyl group, or an alkoxy group, for example, a compound (102) can be obtained by reacting a compound (101) with an alkyl halide in the presence of an appropriate lithium reagent or a metal catalyst to perform a coupling reaction. Similarly, in R^k1When fluorine is used, the compound (103) can be obtained by allowing a fluorinating agent such as N-benzenesulfonylimide to act on the compound (101), and R is^k1In the case of-CN, the compound (104) can be obtained by allowing a cyanide such as copper cyanide to act on the compound (101).

(2) Synthesis of Compound (K1-1) and Compound (K1-2)

[ solution 18]

[ solution 19]

Fumaric chloride (111) is commercially available. The (S) or (R) form of optically active ethyl lactate (112) is commercially available. Compound (113) can be obtained by allowing fumaric chloride (111) to act on optically active ethyl lactate (112) together with a base such as triethylamine.

Then, a Diels-Alder reaction (Diels-Alder reaction) of the compound (113) and the anthracene derivative (114) is performed to stereoselectively produce the compound (114), and an excess amount of a base is further allowed to act to derive the compound (115).

When Dicyclohexylcarbodiimide (DCC) and Dimethylaminopyridine (DMAP) are added to the compound (115), and the appropriate phenol derivative (Rod) is added^k1OH) to obtain the compound (K1-1) according to the embodiment of the present invention. Furthermore, a reducing agent such as Lithium Aluminum Hydride (LAH) is allowed to act on the compoundThe compound (K1-2) can be obtained from the compound (K1-1).

Next, a flow chart is used to generate the bonding group Z^k1An example of the method of (1) will be described. In the scheme, MSG¹Or MSG²Is a monovalent organic group having at least one ring. Multiple MSGs for use in a process¹(or MSG)²) May be the same or may be different. The compounds (1A) to (1K) correspond to the compound (K1).

(I) Formation of single bonds

[ solution 20]

The compound (1A) is synthesized by reacting an arylboronic acid (21) with a compound (22) synthesized by a conventional method in the presence of a catalyst such as tetrakis (triphenylphosphine) palladium and an aqueous carbonate solution. The compound (1A) can also be synthesized by reacting a compound (23) synthesized by a conventional method with n-butyllithium, followed by reaction with zinc chloride, and reacting the compound (22) in the presence of a catalyst such as dichlorobis (triphenylphosphine) palladium.

(II)-CF₂O-and-OCF₂Generation of

[ solution 21]

Compound (26) is obtained by treating compound (1B) with a sulfurizing agent such as Lawesson's reagent. Fluorination of Compound (26) with a hydropyridine fluoride Complex and N-Bromosuccinimide (NBS) to synthesize Compound having-CF₂Compound (1C) of O "(see e.g. promo chem., lett, 1992, 827, by m. Compound (1C) was also synthesized by fluorinating compound (26) with (diethylamino) sulfur trifluoride (DAST) (see Journal of Organic Chemistry, J.or., Bunnelle) of W.H. Banner et alChem.). 1990, 55 th page 768). Having a-OCF₂The compounds of (a) and (b) can also be synthesized using the methods described. These bonding groups can also be formed using the method described in "German applied chemistry (Angew. chem. int. Ed.) 2001, page 1480, 40, by Pear. Kirsch et al.

Formation of (III) -CH ═ CH-

[ solution 22]

After treating compound (22) with N-butyllithium, it is reacted with formamide such as N, N-Dimethylformamide (DMF) to obtain aldehyde (28). Compound (1D) is synthesized by reacting an aldehyde (28) with a phosphorus ylide produced by treating phosphonium salt (27) synthesized by a conventional method with a base such as potassium tert-butoxide. Depending on the reaction conditions, cis-isomer is produced, so that cis-isomer is isomerized to trans-isomer by the existing method as required.

(IV)-(CH₂)₂Generation of

[ solution 23]

Compound (1D) is hydrogenated in the presence of a catalyst such as palladium on carbon, whereby compound (1E) is synthesized.

(V)-(CH₂)₄Generation of

[ solution 24]

Using phosphonium salt (29) in place of phosphonium salt (27), and following the process of item (III) or Item (IV), a compound having- (CH)₂)₂-and-CH ═ CH-compounds. The compound (1F) is synthesized by catalytic hydrogenation of the compound.

Production of (VI) -C.ident.C-

[ solution 25]

Compound (23) is reacted with 2-methyl-3-butyn-2-ol in the presence of a catalyst of palladium dichloride and copper halide, and then deprotected under basic conditions to obtain compound (30). Compound (1G) is synthesized by reacting compound (22) with compound (30) in the presence of a catalyst comprising palladium dichloride and copper halide.

(VII) -CF-Generation

[ solution 26]

Compound (22) is treated with n-butyllithium and then reacted with tetrafluoroethylene to obtain compound (31). Compound (22) is treated with n-butyllithium and then reacted with compound (31) to synthesize compound (1H).

(VIII)-CH₂O-or-OCH₂Generation of

[ solution 27]

Compound (28) is reduced with a reducing agent such as sodium borohydride to obtain compound (32). The compound (32) is halogenated with hydrobromic acid or the like to obtain a compound (33). Compound (1J) is synthesized by reacting compound (25) with compound (33) in the presence of potassium carbonate or the like.

(IX)-(CH₂)₃O-or-O (CH)₂)₃Generation of

[ solution 28]

Compound (1K) was synthesized according to the method of item (VIII) using compound (34) instead of compound (32).

(X)-(CF₂)₂Generation of

A diketone (-COCO-) is fluorinated with sulfur tetrafluoride in the presence of a hydrogen fluoride catalyst according to the method described in J.Am.chem.Soc. in 2001, p.123: 5414₂)₂-a compound of (a).

The liquid crystal composition according to the embodiment of the present invention may further contain at least one of the compounds represented by (K2) to (K8) in which the chiral compound (K1) is added as the chiral component (K).

1.4 achiral Components

The achiral component constituting the liquid crystal composition of the embodiment of the present invention contains at least one achiral compound and exhibits a liquid crystal phase. An achiral component containing at least one of the achiral compounds represented by the formula (1-A) or the formula (1-B) is suitable as a liquid crystal component used as a liquid crystal element. In the liquid crystal composition according to the embodiment of the present invention, in addition to the chiral compound represented by the formula (K1) as the chiral component (K) and at least one of the achiral compounds represented by the formula (1-a) or the formula (1-B), a material generally recognized as a liquid crystal material in the technical field may be further added to be used as another liquid crystal material.

In the liquid crystal composition according to the embodiment of the present invention, the content of the achiral component (T) is usually 80 to 99.9% by weight, preferably 90 to 99.9% by weight.

In the liquid crystal composition according to the embodiment of the present invention, the content of the compound represented by the formula (1-a) or the formula (1-B) in the achiral component (T) is usually 50 to 100% by weight, and preferably 90 to 100% by weight.

Further, in the liquid crystal composition according to the embodiment of the present invention, the content of the compound represented by the formula (1-a) in the achiral component (T) is 50% by weight to 100% by weight, and in this case, an optically isotropic liquid crystal phase can be exhibited.

1.4.1 Structure of Compound represented by formula (1-A) or formula (1-B)

[ solution 29]

In the formula (1-A) and the formula (1-B),

R¹¹and R¹²Each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, at least one-CH group being present in the alkyl group and the alkenyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen.

In this class R¹¹And R¹²Among them, preferred is an alkyl group having 1 to 10 carbon atoms or an alkenyl group having 2 to 10 carbon atoms. More preferably an alkyl group having 2 to 8 carbon atoms or an alkenyl group having 2 to 8 carbon atoms. The preferred steric configuration of-CH ═ CH-in the alkenyl group depends on the position of the double bond. In a process such as-CH ═ CHCH₃、-CH＝CHC₂H₅、-CH＝CHC₃H₇、-CH＝CHC₄H₉、-C₂H₄CH＝CHCH₃and-C₂H₄CH＝CHC₂H₅Such an alkenyl group having a double bond at an odd-numbered position is preferably in a trans configuration. In a reaction system such as-CH₂CH＝CHCH₃、-CH₂CH＝CHC₂H₅and-CH₂CH＝CHC₃H₇In such an alkenyl group having a double bond at an even number position, the cis configuration is preferred. The alkenyl compound having a preferred steric configuration has a high upper limit temperature or a wide temperature range of a liquid crystal phase. Molecular Crystals and Liquid Crystals (mol. crystal. liq. crystal.), page 109, 1985, and page 327, 1985, 131, in detail.

Ring A¹¹Ring A¹²And ring A¹³Each independently is 1, 4-cyclohexylene, 1, 4-phenylene in which at least one hydrogen is substituted by fluorine, 1, 3-dioxane-2, 5-diyl, tetrahydropyran-2, 5-diyl, or pyrimidine-2, 5-diyl.

Ring A¹¹Ring A¹²And ring A¹³Each independently preferably a1, 4-phenylene, 1, 3-dioxane-2, 5-diyl, tetrahydropyran-2, 5-diyl, or 1, 4-cyclohexylene group which may be substituted by halogen.

Z¹¹、Z¹²And Z¹³Each independently is a single bond, -CH₂CH₂-、-COO-、-OCO-、-CH₂O-、-OCH₂-、-CF₂O-、-OCF₂-, -CH ═ CH-, -CF ═ CF-, or-C.ident.C-.

Z¹¹、Z¹²And Z¹³Preferably a single bond, -CH₂CH₂-、-CH＝CH-、-C≡C-、-COO-、-CF₂O-、-OCF₂-、-CH₂O-, or-OCH₂Of these, particularly preferred is a single bond, -COO-or-CF₂O-。

In addition, among these bonds, the groups-CH-, -CF-, -CH- (CH) are mentioned₂)₂-, and- (CH)₂)₂In a bonding group having a double bond such as-CH ═ CH-or the like, the stereoconfiguration is a trans configuration rather than a cis configuration.

X¹¹Is fluorine, chlorine, -SF₅、-CHF₂、-CF₃、-CF₂CH₂F、-CF₂CHF₂、-CF₂CF₃、-(CF₂)₃-F、-CF₂CHFCF₃、-CHFCF₂CF₃、-(CF₂)₄-F、-(CF₂)₅-F、-OCHF₂、-OCF₃、-OCF₂CH₂F、-OCF₂CHF₂、-OCH₂CF₃、-OCF₂CF₃、-O-(CF₂)₃-F、-OCF₂CHFCF₃、-OCHFCF₂CF₃、-O-(CF₂)₄-F、-O-(CF₂)₅-F、-CH＝CF₂、-CH＝CHCF₃or-CH ═ CHCF₂CF₃。

Preferred X¹¹Examples of (a) are fluorine, chlorine, -C ≡ N, -N ═ C ═ S, -CF₃、-CHF₂、-OCF₃and-OCHF₂. Most preferred X¹Examples of (a) are fluorine, chlorine, -C ≡ N, -N ═ C ═ S, -CF₃and-OCF₃。

L¹¹And L¹²Each independently is hydrogen or fluorine, L¹³And L¹⁴Each independently hydrogen, fluorine, chlorine, or-C ≡ N, except that L¹³And L¹⁴Will not all be hydrogen.

Of these, L is preferred¹¹And L¹²Is fluorine, and preferably L¹³And L¹⁴Each independently hydrogen, fluorine or-C ≡ N.

S¹¹Is hydrogen or methyl.

m and n are each independently 0 or 1.

The compound represented by the formula (1-A) is particularly preferably any one of the compounds represented by the following formulae (1-A-01) to (1-A-22).

[ solution 30]

[ solution 31]

[ solution 32]

The compound represented by the formula (1-B) is particularly preferably any one of the compounds represented by the following formulae (1-B-01) to (1-B-22).

[ solution 33]

[ chemical 34]

(formula (1-A-01) to formula (1-A-22), and formula (1-B-01) to formula (1-B-22) wherein R¹¹And R¹²Is hydrogen, alkyl group having 1 to 8 carbon atoms, alkenyl group having 2 to 8 carbon atoms, or alkoxy group having 1 to 8 carbon atoms, A¹¹And A¹²Is 1, 4-cyclohexylene, 1, 3-dioxane-2, 5-diyl or tetrahydropyran-2, 5-diyl, X¹¹Is fluorine, chlorine, -CF₃、-CHF₂、-CH₂F、-OCF₃、-OCHF₂、-OCH₂F. -CN, or-C ═ C-CF₃And (F) is hydrogen or fluorine. )

1.3.2 Properties of achiral Compounds represented by formula (1-A) and formula (1-B)

The compound (1-A) has a positive dielectric anisotropy. On the other hand, the compound (1-B) has negative dielectric anisotropy.

By appropriately selecting the left terminal group R in the compound (1-A) and the compound (1-B)¹¹The right terminal group X¹¹And the right terminal group R¹²Ring A¹¹Ring A¹³The kind of (c); a bonding group Z¹¹A bonding group Z¹³Group on the terminal phenylene Ring and substitution position thereof (L)¹¹、L¹²、L¹³、L¹⁴And S¹¹) (ii) a A bonding group Z¹¹A bonding group Z¹³And a combination of m and n, and the like, and the physical properties of the achiral component (T), such as the transparent point, refractive index anisotropy, and dielectric anisotropy, can be adjusted.

The following pairs of left terminal groups R¹¹The right terminal group X¹¹And the right terminal group R¹²Ring A¹¹Ring A¹³A bonding group Z¹¹A bonding group Z¹³、L¹¹～L¹⁴The kind of combination of m and n, and the like with the compound (1)General relationships between physical properties of the compound (1-B) and the compound (A) will be described.

When R is¹¹Or R¹²When the compound (1-A) and the compound (1-B) are linear, the liquid crystal phase has a wide temperature range and a small viscosity. On the other hand, when R¹¹Or R¹²When the branched chain is branched, the compatibility of the compound (1-A) and the compound (1-B) in the liquid crystal composition is good.

When R is¹¹Or R¹²When the alkenyl group is used, the viscosity is small and the compatibility in the liquid crystal composition is good.

When R is¹¹Or R¹²The alkoxy group has a large dielectric anisotropy and is excellent in compatibility with the liquid crystal composition.

Ring A¹¹Ring A¹³The larger the number of aromatic rings contained therein, the larger the refractive index anisotropy of the compound (1-A) and the compound (1-B) becomes. When ring A¹¹Ring A¹³When at least one hydrogen is fluorine-substituted 1, 4-phenylene, 1, 3-dioxane-2, 5-diyl, tetrahydropyran-2, 5-diyl, or pyrimidine-2, 5-diyl, respectively, it is effective in exhibiting large dielectric anisotropy, when ring a¹¹Ring A¹³When they are 1, 4-cyclohexylene and tetrahydropyran-2, 5-diyl rings, respectively, they contribute to the exhibition of good compatibility of the compound (1-A) or the compound (1-B).

When bonding group Z¹¹A bonding group Z¹²And a bonding group Z¹³Are each a single bond, -CH₂CH₂-、-CH＝CH-、-CF₂O-、-OCF₂-、-CH₂O-、-OCH₂-、-CF＝CF-、-(CH₂)₃-O-、-O-(CH₂)₃-、-(CH₂)₂-CF₂O-、-OCF₂-(CH₂)₂-or- (CH)₂)₄when-H-is contained, the viscosity of the compound (1-A) or the compound (1-B) is small. In addition, when the bonding group Z¹¹A bonding group Z¹²And a bonding group Z¹³Are each a single bond, - (CH)₂)₂-、-CF₂O-、-OCF₂when-or-CH ═ CH-, the viscosity of compound (1-a) or compound (1-B) becomes further small. When bonding group Z¹¹A bonding group Z¹²And, anda bonding group Z¹³When the refractive index is-C.ident.C-, respectively, the refractive index anisotropy of the compound (1-A) or the compound (1-B) is large. When bonding group Z¹¹A bonding group Z¹²And a bonding group Z¹³Are each-COO-or-CF₂O-is a compound having a large dielectric anisotropy, such as the compound (1-A) or the compound (1-B). When Z is¹¹、Z¹²And Z¹³Are each a single bond, - (CH)₂)₂-、-CH₂O-、-CF₂O-、-OCF₂-, or- (CH)₂)₄In the case of (1-a), the compound (1-a) or the compound (1-B) is chemically stable and is not easily deteriorated.

In general, when the refractive index anisotropy or the dielectric anisotropy is large, the driving voltage of the liquid crystal element according to the embodiment of the present invention tends to be low, and the response speed is high when the viscosity is low.

When X is present¹¹Is fluorine, chlorine, -SF₅、-CHF₂、-CF₃、-CH₂F、-OCF₃、-OCHF₂or-OCH₂When F is used, the compound (1-A) has a large dielectric anisotropy. When X is present¹¹Is fluorine or-OCF₃And the chemical property is stable.

When L is¹¹And L¹²Are all fluorine, and X¹¹Is fluorine, chlorine, -SF₅、-CF₃、-CHF₂、-CH₂F、-OCF₃、-OCHF₂or-OCH₂In case of F, the compound (1-A) has very large dielectric anisotropy. In addition, when L is¹¹Is fluorine and L¹²Is hydrogen, X¹¹is-CF₃or-OCF₃When the current is over; l is¹¹And L¹²Are all fluorine, and X¹¹is-CF₃or-OCF₃When the current is over; or L¹¹、L¹²And X¹¹When both fluorine compounds are used, the compound (1-A) has a large dielectric anisotropy, a wide temperature range of a liquid crystal phase, and further has stable chemical properties and is less likely to cause deterioration.

In addition, when L is¹³And L¹⁴Are all fluorine, and R¹²In the case of an alkoxy group, the compound (1-B) has a large dielectric anisotropy and a wide temperature range of a liquid crystal phase. In addition, when L is¹³Is fluorine, and R¹²In the case of an alkyl group, the compound (1-B) has a large dielectric anisotropy and is chemically stable and less likely to cause deterioration.

The larger m + n is, the higher the clearing point of the compound is, and the smaller m + n is, the lower the melting point of the compound (1-A) is.

1.3.3 other achiral Components

For the purpose of optimizing the characteristics of the liquid crystal composition of the embodiment of the present invention, a compound represented by the following formula (1-C) may be used as the achiral component as necessary.

[ solution 35]

In the formula (1-C),

R¹¹and R¹²Each independently represents hydrogen, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, or an alkoxy group having 1 to 8 carbon atoms;

Z¹¹and Z¹²Each independently is a single bond, -CH₂CH₂-、-COO-、-OCO-、-CH₂O-、-OCH₂-、-CF₂O-、-OCF₂-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-;

ring A¹¹And ring A¹²Each independently is 1, 4-cyclohexylene, 1, 4-phenylene in which at least one hydrogen is substituted with fluorine, 1, 3-dioxane-2, 5-diyl, tetrahydropyran-2, 5-diyl, or pyrimidine-2, 5-diyl;

p is 1, 2, or 3.

The compound (1-C) is a compound having a small dielectric anisotropy and exhibits a low viscosity. Terminal group R for Compound (1-C)¹¹And the terminal group R¹²Ring A¹¹And ring A¹²A bonding group Z¹¹And a bonding group Z¹²The general relationship between the kind of the combination (B) and the physical properties is similar to that described for the compound (1-A) and the compound (1-B).

Regarding p, when p is 1, the clearing point is low and the viscosity is low. When p is 2, the balance between the transparency and the viscosity is good, and when p is 3, the transparency is high.

The compound represented by the formula (1-C) is particularly preferably any one of the compounds represented by the following formulae (1-C-01) to (1-C-14).

[ solution 36]

In the formulae (1-C-01) to (1-C-14), R¹¹And R¹²Each independently hydrogen, C1-C8 alkyl, C2-C8 alkenyl, or C1-C8 alkoxy, A¹¹And A¹²Each independently is 1, 4-cyclohexylene, 1, 3-dioxane-2, 5-diyl, or tetrahydropyran-2, 5-diyl, (F) is hydrogen or fluorine.

2. Monomer/liquid crystal mixture comprising liquid crystal composition and polymerizable monomer, and polymer/liquid crystal composite material

The second embodiment of the present invention is a mixture of a liquid crystal composition containing a liquid crystal phase having a chiral nematic phase or an optically isotropic liquid crystal phase and a polymerizable monomer. In the present specification, the term "polymerizable monomer" is a concept including a macromonomer or oligomer.

When the monomer/liquid crystal mixture containing the liquid crystal composition and the polymerizable monomer is used as a material for a liquid crystal element having a light modulation layer such as a light modulation window, for example, a liquid crystal element which can be driven at a lower voltage and has higher contrast characteristics can be manufactured. In order to control the structure of a transparent substance which becomes a part of a light control layer of a liquid crystal element described later according to the purpose, it is preferable to use the monomer/liquid crystal mixture according to the embodiment of the present invention.

The third embodiment of the present invention is a polymer/liquid crystal composite material, and can be produced, for example, by polymerizing a monomer/liquid crystal mixture containing a liquid crystal composition and a polymerizable monomer according to the second embodiment of the present invention. The polymer/liquid crystal composite material according to the embodiment of the present invention preferably has a chiral nematic phase or an optically isotropic liquid crystal phase. The polymer/liquid crystal composite material is not particularly limited as long as it is a composite material containing both a liquid crystal composition and a polymer compound, and may be in a state in which the polymer and the liquid crystal composition are phase separated in a state in which a part or all of the polymer is not dissolved in the liquid crystal composition.

The optically isotropic polymer/liquid crystal composite according to the embodiment of the present invention can exhibit an optically isotropic liquid crystal phase in a wide temperature range. Further, since a low driving voltage and a very fast response speed can be achieved, these effects can be preferably used for a liquid crystal element for display or the like.

The polymer/liquid crystal composite showing a chiral nematic phase according to the preferred embodiment of the present invention can exhibit a chiral nematic phase over a wide temperature range. In addition, a sufficient contrast between opacity and transparency due to light scattering can be obtained with and without applying a voltage.

2.1 polymerization conditions in the production of Polymer/liquid Crystal composites

The polymer/liquid crystal composite material of the present invention can also be produced by mixing a liquid crystal composition with a polymer obtained by polymerization in advance, and is preferably produced by mixing a low molecular weight monomer, a macromonomer, an oligomer or the like (hereinafter collectively referred to as "polymerizable monomer") which is a polymer material with a liquid crystal composition and then performing a polymerization reaction in the mixture.

In the present specification, the mixture containing the liquid crystal composition and the polymerizable monomer according to the second embodiment of the present invention is also referred to as a "monomer/liquid crystal mixture". The "monomer/liquid crystal mixture" may contain a polymerization initiator, a curing agent, a catalyst, a stabilizer, a dichroic dye (merocyanine, styrene, azo, azomethine, azoxy, quinophthalone, anthraquinone, tetrazine, or the like), a photochromic compound, or the like, as required, as long as the effects of the present invention are not impaired. For example, the monomer/liquid crystal mixture according to the embodiment of the present invention may contain a polymerization initiator in an amount of 0.1 to 20 parts by weight based on the polymerizable monomer, if necessary.

In the case of producing a polymer/liquid crystal composite having optical isotropy, it is preferable that polymerization in a monomer/liquid crystal mixture containing a liquid crystal composition and a polymerizable monomer is carried out in a non-liquid crystal isotropic phase or an optically isotropic liquid crystal phase. That is, the polymerization temperature is preferably a temperature at which the polymer/liquid crystal composite exhibits high transparency and isotropy. More preferably, the polymerization is terminated at a temperature at which the mixture of the polymerizable monomer and the liquid crystal composition exhibits a non-liquid-crystal isotropic phase or a blue phase, and in a non-liquid-crystal isotropic phase or an optically isotropic liquid crystal phase. That is, it is preferable to set the polymerization temperature at which the polymer/liquid crystal composite exhibits optical isotropy without substantially scattering light on the longer wavelength side than visible light after polymerization.

In addition, when the polymer/liquid crystal composite material according to the embodiment of the present invention is used as a light modulation layer, light may be irradiated in a state where a voltage is applied between transparent electric films during polymerization reaction.

2.2 Polymer raw Material for Polymer/liquid Crystal composite Material

As a raw material of the polymer constituting the polymer/liquid crystal composite material according to the embodiment of the present invention, for example, a low molecular weight monomer, a macromer, or an oligomer can be used as a polymerizable monomer. In addition, since the obtained polymer preferably has a three-dimensional crosslinked structure, it is preferable to use a polyfunctional monomer having two or more polymerizable functional groups as a raw material of the polymer. The polymerizable functional group is not particularly limited, and examples thereof include an acrylic group, a methacrylic group, a glycidyl group, an epoxy group, an oxetane group, a vinyl group, and the like, and from the viewpoint of polymerization rate, an acrylic group and a methacrylic group are preferable. In the polymer raw material, it is preferable to add 10% by weight or more of a monomer containing two or more polymerizable functional groups to the raw material because high transparency and isotropy are likely to be exhibited in the polymer/liquid crystal composite material according to the embodiment of the present invention.

In order to obtain a preferable composite material, the polymer preferably has a mesogenic site, and a monomer having a mesogenic site may be used as a raw material of the polymer in a part or all of the polymer.

2.2.1 monomers having a mesogen moiety (mono-, di-and tri-reactive monomers)

The mono-, di-or tri-reactive monomer having a mesogen moiety is not particularly limited in structure, and examples thereof include any of compounds represented by the following formulae (M1), (M2) and (M3).

[ solution 37]

In the formulae (M1) to (M3), R^MAIs hydrogen, halogen, -CF₃、-OCF₃C ≡ N, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an alkoxycarbonyl group having 2 to 20 carbon atoms. Preferred R^MAIs an alkyl group having 1 to 20 carbon atoms or an alkoxy group having 1 to 20 carbon atoms.

R^MBIndependently represent a polymerizable group of the groups (M3-1) to (M3-7).

[ solution 38]

Here, R in the radicals (M3-1) to (M3-7)^dEach independently hydrogen, halogen or alkyl having 1 to 5 carbon atoms, wherein at least one hydrogen of the alkyl groups is substituted by halogen. Preferred R^dHydrogen, fluorine and methyl.

The radical (M3-2), the radical (M3-3), the radical (M3-4) and the radical (M3-7) are preferably polymerized by radical polymerization. The group (M3-1), the group (M3-5) and the group (M3-6) are preferably polymerized by cationic polymerization. Since the polymerization is all living polymerization, the polymerization starts as long as a small amount of radical or cationic active species is generated in the reaction system. The polymerization initiator may be used for the purpose of accelerating the generation of active species. For example, light or heat may be used to generate the active species.

A^MEach independently is an aromatic or non-aromatic 5-membered ring, 6-membered ring or condensed ring having 9 or more carbon atoms, -CH₂May be substituted by-O-, -S-, -NH-, or-NCH₃-substituted, wherein-CH ═ in the ring may be substituted with-N ═ and hydrogen atoms in the ring may be substituted with halogen, alkyl groups having 1 to 5 carbon atoms, or halogenated alkyl groups.

Preferred A^MThe concrete example is as follows: 1, 4-cyclohexylene group, 1, 4-phenylene group, 1, 4-cyclohexenylene group, 2-fluoro-1, 4-phenylene group, 2, 3-difluoro-1, 4-phenylene group, 2, 5-difluoro-1, 4-phenylene group, 2, 6-difluoro-1, 4-phenylene group, 2-methyl-1, 4-phenylene group, 2-trifluoromethyl-1, 4-phenylene group, 2, 3-bis (trifluoromethyl) -1, 4-phenylene group, naphthalene-2, 6-diyl group, tetrahydronaphthalene-2, 6-diyl group, fluorene-2, 7-diyl group, 9-methylfluorene-2, 7-diyl group, 1, 3-dioxane-2, 5-diyl group, Pyridine-2, 5-diyl, and pyrimidine-2, 5-diyl. Furthermore, the stereoconfiguration of the 1, 4-cyclohexylene group and 1, 3-dioxane-2, 5-diyl group is a trans configuration rather than a cis configuration.

Further, since 2-fluoro-1, 4-phenylene and 3-fluoro-1, 4-phenylene are structurally the same, the latter is not exemplified. The rule also applies to the relationship of 2, 5-difluoro-1, 4-phenylene to 3, 6-difluoro-1, 4-phenylene, and the like.

Y^MEach independently a single bond or an alkylene group having 1 to 20 carbon atoms, at least one-CH group being contained in the alkylene group₂-may be substituted by-O-, -S-, -CH ═ CH-, -C ≡ C-, -COO-, or-OCO-, but not two oxygen atoms are adjacent as in-O-. Preferred is Y^MIs a single bond, - (CH)₂)_m2-、-O(CH₂)_m2-, and- (CH)₂)_m2O- (in the formula, m2 is an integer of 1-20).

Z^MAre each independently a single bond, - (CH)₂)_m3-、-O(CH₂)_m3-、-(CH₂)_m3O-、-O(CH₂)_m3O-、-CH＝CH-、-C≡C-、-COO-、-OCO-、-(CF₂)₂-、-(CH₂)₂-COO-、-OCO-(CH₂)₂-、-CH＝CH-COO-、-OCO-CH＝CH-、-C≡C-COO-、-OCO-C≡C-、-CH＝CH-(CH₂)₂-、-(CH₂)₂-CH＝CH-、-CF＝CF-、-C≡C-CH＝CH-、-CH＝CH-C≡C-、-OCF₂-(CH₂)₂-、-(CH₂)₂-CF₂O-、-OCF₂-, or-CF₂O- (in the formula, m3 is an integer of 1-20).

Preferred Z^MIs a single bond, - (CH)₂)_m3-、-O(CH₂)_m3-、-(CH₂)_m3O-、-CH＝CH-、-C≡C-、-COO-、-OCO-、-(CH₂)₂-COO-、-OCO-(CH₂)₂-、-CH＝CH-COO-、-OCO-CH＝CH-、-OCF₂-, and-CF₂O- (in the formula, m3 is an integer of 1-20).

m1 is an integer of 0 to 2. When the total of m1 is 1, the bicyclic compound has two 6-membered rings or the like. When the sum of m1 is 2 or 3, the compounds are tricyclic and tetracyclic, respectively. In addition, when there are a plurality of m1, two or more A^MOr more than two Z^MMay be the same or may be different. For R^MBAnd Y^MThe same is true.

The compounds represented by the formulae (M1) to (M3) are contained in an amount larger than that of the naturally occurring compound²H (deuterium),¹³C-like isotopes have the same properties and are therefore preferably used.

More preferred examples of the compounds (M1) to (M3) are compounds represented by the following formulae (M1-1) to (M1-16), formulae (M2-1) to (M2-14), and formulae (M3-1) to (M3-3). In these compounds, R^MA、R^MB、Z^M、A^MAnd Y^MThe meanings of (a) are the same as those of the formulae (M1) and (M2) described in examples of the present invention.

The following partial structures of the compounds (M1-1) to (M1-16), the compounds (M2-1) to (M2-14), and the compounds (M3-1) to (M3-3) will be described. Part of the structure (a1) represents a1, 4-phenylene group in which at least one hydrogen may be substituted by fluorine or a methyl group. The partial structure (a2) represents fluorene in which hydrogen at the 9-position may be substituted with a methyl group.

[ solution 39]

[ solution 40]

[ solution 41]

[ solution 42]

[ solution 43]

[ solution 44]

The following monomers having no mesogen portion, and polymerizable compounds other than the monomer (M1) having a mesogen portion and the monomer (M2) may be used as necessary.

2.2.2 monomers having polymerizable functional groups without mesogen sites

Examples of the monomer having a polymerizable functional group without a mesogen portion include linear acrylate or branched acrylate having 1 to 30 carbon atoms, linear methacrylate or branched methacrylate having 1 to 30 carbon atoms, linear diacrylate or branched diacrylate having 1 to 30 carbon atoms, and linear dimethacrylate or branched dimethacrylate having 1 to 30 carbon atoms, and examples of the monomer having three or more polymerizable functional groups include glycerol-propoxylate (1PO/OH) triacrylate, pentaerythritol-propoxylate-triacrylate, pentaerythritol-triacrylate, trimethylolpropane-ethoxylate-triacrylate, trimethylolpropane-propoxylate-triacrylate, trimethylolpropane-triacrylate, mixtures thereof, and the like, Di (trimethylolpropane) tetraacrylate, pentaerythritol tetraacrylate, di (pentaerythritol) pentaacrylate, and di (pentaerythritol) hexaacrylate, but the monomer is not limited to these monomers.

2.3 polymerization initiators

The polymerization reaction in the production of the polymer constituting the polymer/liquid crystal composite material according to the embodiment of the present invention is not particularly limited, and for example, photo radical polymerization, thermal radical polymerization, photo cation polymerization, and the like are performed.

Examples of the photo radical polymerization initiator usable in the photo radical polymerization are: DAROCUR (DAROCUR)1173 and 4265 (both trade names, BASF Japan), gorgeous good (IRGACURE)184, 369, 500, 651, 784, 819, 907, 1300, 1700, 1800, 1850, and 2959 (both trade names, Japan).

Examples of preferable initiators for radical polymerization by heat which can be used in the thermal radical polymerization are: benzoyl peroxide, diisopropyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, tert-butyl peroxydiisobutyrate, lauroyl peroxide, dimethyl 2,2' -azobisisobutyrate (MAIB), di-tert-butyl peroxide (DTBPO), Azobisisobutyronitrile (AIBN), Azobiscyclohexane Carbonitrile (ACN), and the like.

Examples of the photo-cationic polymerization initiator that can be used for photo-cationic polymerization include diaryliodonium salts (hereinafter referred to as "DAS") and triarylsulfonium salts (hereinafter referred to as "TAS"). Specific trade names of the photo cation polymerization initiators are exemplified by: hilbert (Cyracure) UVI-6990, Hilbert UVI-6974, Hilbert UVI-6992 (trade name, UCC (stock)), Adeka optoma (Adeka Optomer) SP-150, SP-152, SP-170, SP-172 (trade name, Adeka (stock)), Rodocile Photoinitiator (Rhodorsil Photoapplicator) 2074 (trade name, Rhodia Japan)), Yangma Jia (IRGACURE)250 (trade name, Nippon Basff (stock)), and UV-9380C (trade name, GE Toba ShilicSilicone (stock)), etc.

2.4 curing agents and the like

In the production of the polymer constituting the polymer/liquid crystal composite material according to the embodiment of the present invention, one or more other preferable components may be further added in addition to the monomer and the polymerization initiator, and for example, one or more selected from a curing agent, a catalyst, a stabilizer, a chain transfer agent, a photosensitizer, a dye crosslinking agent, and the like may be added.

As the hardener, a conventional latent hardener which is generally used as a hardener for epoxy resins can be used. Examples of the latent epoxy resin curing agent include: amine-based curing agents, novolac-based curing agents, imidazole-based curing agents, and acid anhydride-based curing agents.

In addition, a curing accelerator for accelerating a curing reaction between a polymerizable compound having a glycidyl group, an epoxy group, and an oxetane group and a curing agent may be further used. Examples of the hardening accelerator include: tertiary amines such as benzyldimethylamine, tris (dimethylaminomethyl) phenol and dimethylcyclohexylamine, imidazoles such as 1-cyanoethyl-2-ethyl-4-methylimidazole and 2-ethyl-4-methylimidazole, organophosphorus compounds such as triphenylphosphine, quaternary phosphonium salts such as tetraphenylphosphonium bromide, diazabicycloalkenes such as 1, 8-diazabicyclo [5.4.0] undecene-7 and organic acid salts thereof, quaternary ammonium salts such as tetraethylammonium bromide and tetrabutylammonium bromide, boron compounds such as boron trifluoride and triphenylborate, and the like. These hardening accelerators may be used alone or in combination of two or more.

In addition, for example, in order to prevent undesired polymerization during storage, it is preferable to add a stabilizer. All compounds known to the person skilled in the art can be used as stabilizers. Typical examples of the stabilizer include: 4-ethoxyphenol, hydroquinone, and Butylated Hydroxytoluene (BHT).

2.5 content ratio of polymerizable monomer and the like in monomer/liquid Crystal mixture

The content of the polymerizable monomer contained in the monomer/liquid crystal mixture according to the embodiment of the present invention can be adjusted depending on the purpose of use. In the case of using as a material for forming a light control layer of a liquid crystal cell, in order to obtain a sufficient contrast between opacity and transparency due to light scattering, the polymerizable monomer is contained in the monomer/liquid crystal mixture preferably in a range of 0.1 to 50% by weight, more preferably in a range of 0.1 to 40% by weight, and still more preferably in a range of 0.1 to 10% by weight.

The content of the liquid crystal composition in the polymer/liquid crystal composite material according to the embodiment of the present invention differs depending on the purpose of use, and is preferably as low as possible as long as the polymer/liquid crystal composite material can exhibit optical isotropy or the composite material can exhibit a required helical pitch, and it is possible to reduce the driving voltage, increase the response speed, improve the electric birefringence (kerr coefficient), and increase the contrast of the polymer/composite material according to the embodiment of the present invention.

2.6 other ingredients

The polymer/liquid crystal composite material according to the embodiment of the present invention may contain, for example, a dichroic dye or a photochromic compound within a range not to impair the effects of the present invention.

3 liquid crystal element

3.1 liquid Crystal element Using optically Isotropic liquid Crystal composition

A fourth example of the present invention is a liquid crystal device that includes the optically isotropic one of the liquid crystal composition or the polymer/liquid crystal composite (hereinafter, the liquid crystal composition and the polymer/liquid crystal composite are collectively referred to as a "liquid crystal medium") according to the embodiment of the present invention and is driven with an optically isotropic liquid crystal phase.

As an example of the structure of a liquid crystal display element using an optically isotropic liquid crystal composition, there is a structure in which electrodes 1 extending from the left side and electrodes 2 extending from the right side of a comb-shaped electrode substrate are alternately arranged as shown in fig. 1. When a potential difference exists between the

electrodes

1 and 2, an electric field in both the upper direction and the lower direction can be applied to the comb-shaped electrode substrate shown in fig. 1.

3.2 liquid Crystal cell Using liquid Crystal composition exhibiting chiral nematic phase

The fifth example of the present invention is a liquid crystal element using the liquid crystal composition or the polymer/liquid crystal composite material according to the embodiment of the present invention, which shows a chiral nematic phase, as a light control material.

The liquid crystal element of the embodiment of the invention includes: two substrates having electrode layers and at least one of which is transparent, and a light modulation layer supported between the substrates. The light modulation layer contains the polymer/liquid crystal composite material described above. Here, the polymer contained in the polymer/liquid crystal composite material is preferably transparent. It is important that the polymer/liquid crystal composite forms a continuous layer, and forms an optical boundary surface by forming a disordered state of liquid crystal molecules, thereby expressing light scattering.

The polymer in the polymer/liquid crystal composite material in the light modulation layer includes a polymer of a polymerizable monomer included in a monomer/liquid crystal mixture, but may be dispersed in a fibrous or particulate form, a film form in which the polymer/liquid crystal composite material is dispersed in a droplet form, or a gel form having a three-dimensional mesh structure.

In the substrate, a transparent or opaque electrode may be appropriately disposed on the entire surface or a part thereof according to the purpose. In addition, at least one of the substrates has transparency, but is not necessarily completely transparent. In this case, if the liquid crystal element is used to function with light passing from one side of the liquid crystal element to the other side, appropriate transparency can be provided to both substrates.

The substrate used in the liquid crystal element may be a strong material such as glass, metal, or the like, or may be a flexible material such as a plastic film. In the liquid crystal element, the two substrates face each other with an appropriate distance therebetween.

Further, an alignment film of polyimide or the like may be disposed over the entire surface or a part of at least one of the substrates as necessary. Further, a spacer for maintaining the gap may be interposed between the two substrates, as in a conventional liquid crystal element.

In the liquid crystal element according to the embodiment of the present invention, the liquid crystal element driven in the reverse mode (reverse mode) can be manufactured, for example, as follows.

That is, the monomer/liquid crystal mixture is interposed between two substrates having an electrode layer and at least one of which is transparent, and the polymerizable monomer contained in the monomer/liquid crystal mixture is polymerized by ultraviolet irradiation through the transparent substrate or heating the transparent substrate, whereby a liquid crystal element having a light-adjusting layer containing a polymer and a liquid crystal compound can be produced.

Fig. 3 schematically shows an example of a liquid crystal element driven in the reverse mode. Fig. 3(a) shows a state where no voltage is applied, and the panel becomes transparent because the liquid crystal compound is aligned in a planar shape (planar) and light is transmitted. Fig. 3(b) shows a state where a voltage is applied, and the liquid crystal compound is aligned in a homogeneous phase (homogeneous phase) and light is scattered, so that the panel is opaque.

In the liquid crystal element according to the embodiment of the present invention, the liquid crystal element driven in the normal mode (normal mode) can be manufactured as follows, for example. That is, the monomer/liquid crystal mixture is interposed between two substrates having an electrode layer and at least one of which is transparent, and a polymerizable monomer contained in the monomer/liquid crystal mixture is polymerized by applying a specific saturation voltage to the liquid crystal compound and irradiating ultraviolet rays through the transparent substrate or heating the transparent substrate, thereby producing a liquid crystal element having a light-adjusting layer containing a polymer and a liquid crystal compound.

Fig. 4 shows a schematic diagram of an example of a liquid crystal element driven in a normal mode according to the present invention. Fig. 4(a) shows a state where no voltage is applied, and the liquid crystal compound is aligned in a focal-conic shape (focal-conic) and light is scattered, so that the panel is opaque. Fig. 4(b) shows a state where a voltage is applied, and the liquid crystal compound is oriented vertically (homeotropic) and light is transmitted, so that the panel becomes transparent.

Further, a method of interposing a monomer/liquid crystal mixture as a material for forming a light modulation layer between two substrates is not particularly limited as long as the monomer/liquid crystal mixture is injected between the substrates by a conventional injection technique. For example, it can be uniformly applied to one of the substrates using a suitable solution coater, spin coater, or the like, and then the other substrate is stacked and pressed.

The thickness of the light-modulating layer having light scattering properties in the liquid crystal element of the present invention can be adjusted according to the intended use, and the thickness (substrate interval) of the layer is preferably in the range of 2 μm to 40 μm, and more preferably in the range of 6 μm to 25 μm, in order to obtain a sufficient contrast between opacity and transparency due to light scattering.

The liquid crystal element according to the embodiment of the present invention can be used for various applications such as architectural applications such as interior decoration and automobile applications such as automobile blades (leaves) as a light control window, a light modulation device (light modulation device) and the like.

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples. Unless otherwise specified, "%" means "% by weight".

Examples

In the examples of the present specification, I represents a non-liquid crystal isotropic phase, N represents a nematic phase, N represents a chiral nematic layer, BP represents a blue phase, and BPX represents an optically isotropic liquid crystal phase in which no diffracted light of two or more colors is observed. In this specification, the I-N phase transition point is sometimes referred to as the N-I point. The I-N phase transition point is sometimes referred to as the N x-I point. The I-BP phase transition point is sometimes referred to as the BP-I point.

In the examples of the present specification, unless otherwise specified, the measurement and calculation of physical properties and the like are carried out according to the methods described in Japanese Standard of Electronic Industries of Japan (Japan) and EIAJ ED-2521A. Specific measurement methods, calculation methods, and the like are as follows.

1) I-N phase transition Point (T)_NI)

A sample was placed on a hot plate of a melting point measuring apparatus equipped with a polarizing microscope, and in a state of crossed nicols (cross nicols), the temperature was first raised to a temperature at which the sample became a non-liquid crystal isotropic phase, and then lowered at a rate of 1 ℃/min, so that a chiral nematic phase or an optically anisotropic phase was completely expressed. The phase transition temperature in the process was measured, followed by heating at a rate of 1 ℃/min. In the optically isotropic liquid crystal phase, when it is difficult to distinguish a phase transition point in a dark field under crossed nicols, the phase transition temperature is measured by shifting the polarizing plate from the crossed nicols state by 1 ° to 10 °.

2) Refractive index (n/and n ≠ n; measured at 25℃)

The measurement was performed using light having a wavelength of 589nm by an Abbe refractometer having a polarizing plate attached to an eyepiece lens. After rubbing (rubbing) the surface of the main prism in one direction, the sample was dropped on the main prism. The refractive index (n/is measured when the direction of polarization is parallel to the direction of rubbing. The refractive index (n ″) was measured when the direction of polarized light was perpendicular to the direction of rubbing.

3) The pitch (P; measured at 25 ℃; nm)

Pitch length was measured by selective reflection (liquid crystal, manufactured by 2000, pp. 196). With regard to the selective reflection wavelength λ, the relation < n > p/λ 1 holds. Here, < n > represents an average refractive index and is obtained by the following formula. < n > { (n /)²+n⊥²)/2}^1/2. The selective reflection wavelength is measured by a microspectrophotometer (tsukamur electronics ltd., trade name FE-3000). The pitch is found by dividing the obtained reflection wavelength by the average refractive index.

The pitch of the cholesteric liquid crystal having a reflection wavelength in a longer wavelength region or a shorter wavelength region than visible light and the cholesteric liquid crystal which is difficult to measure is determined as follows: the selective reflection wavelength (λ ') is measured by adding a chiral compound (concentration C') at a concentration such that the selective reflection wavelength is present in the visible light region, and the original selective reflection wavelength (λ) is calculated by a linear extrapolation method (λ ═ λ '× C'/C) from the original concentration (C) of the chiral compound.

4) HTP (helical twisting power) (measured at 25 ℃; mum of^-1)

The HTP is obtained from the following equation using the average refractive index < n > and the pitch value obtained by the above method. HTP ═ n >/(× C). λ represents the selective reflection wavelength (nm), and C represents the concentration (wt%) of the chiral compound.

5) A voltage holding ratio (VHR; measured at 60 ℃; %)

The TN element used for the measurement had a polyimide alignment film, and the interval (cell gap) between the two glass substrates was 5 μm. After the sample is injected, the element is sealed with an adhesive cured with ultraviolet rays. The decay voltage after charging by applying a pulse voltage (5V, 60 μ s) to the TN element was measured by a high-speed voltmeter for 16.7ms, and the area a between the voltage curve and the horizontal axis in a unit period (30Hz) was obtained. The area B is the area when not attenuated. The voltage holding ratio (%) is expressed as a percentage of the area a to the area B.

6) Measurement of transmitted light intensity of cell and calculation of transmittance of cell

In an ultraviolet-visible spectrophotometer V650DS manufactured by japan spectro corporation, cells were arranged so that light source light was perpendicular to the cell surfaces, and the transmitted light intensity at a wavelength of 450nm was measured. The bandwidth of the incident light at this time was 5 nm. The transmittance/% of the cell is calculated by the transmitted light intensity of the cell as the measurement object/(the light intensity measured in a state where the cell as the measurement object is not put into the spectrometer) × 100. The transmission light intensity of the cell in the state where a voltage is applied to the cell and the transmission light intensity of the cell in the state where no voltage is applied are measured using the electric field applying means and the bipolar power source. The electric field applying unit uses a waveform generating apparatus 33210A manufactured by Agilent, inc, and the bipolar power source uses NF ELECTRONIC INSTRUMENTS 4010 manufactured by NF, inc.

7) Calculation of contrast ratio

The contrast ratio is the ratio of the intensity of transmitted light in a specific situation to the intensity of transmitted light in a different situation.

The proportion (percentage) of the component or the liquid crystal compound is a weight percentage (wt%) based on the total weight of the liquid crystal compound. The composition is prepared by measuring the weight of the components such as the liquid crystal compound and mixing them. Therefore, the weight% of the component can be easily calculated.

[ example 1]

< Synthesis of Compound (K101) >

[ solution 45]

(in the compound (K1-1), Rodk1 ═ Rod1-1C, nk1 ═ nk2 ═ 0, and R is^k2＝C₅H₁₁A compound of (1)

Compound (K101) was synthesized according to the following scheme.

[ solution 46]

(first stage) Synthesis of Compound (103)

A solution of compound (102) (38.6g, 326mmol) and triethylamine (36.4g, 360mmol) in toluene (150mL) was prepared under nitrogen, and compound (101) (25.0g, 163mmol) was slowly added dropwise at room temperature, and stirring was carried out for 1 hour while maintaining the temperature. The reaction solution was filtered to remove insoluble materials, poured into water, and toluene (100mL) was added thereto, and the organic phase was washed twice with water, and then concentrated, and the residue was isolated and purified by silica gel column chromatography (developing solvent: toluene/ethyl acetate 1/1) to obtain compound (103) (15.7g, 163 mmol).

(second stage) Synthesis of Compound (104)

A solution of the compound (103) (29.6g, 93.5mmol) obtained in the previous stage and anthracene (25g, 140mmol) in toluene (150mL) was heated and stirred at 110 ℃ for 3 days under nitrogen atmosphere. After the reaction mixture was dissolved and residual anthracene was removed, the organic phase was concentrated, and the residue was isolated and purified by silica gel column chromatography (developing solvent: toluene/ethyl acetate 4/1) to obtain compound (104) (46.2g, 93.5mmol) as a white crystal.

(third stage) Synthesis of Compound (105)

A mixed solution of the compound (104) (20g, 40.4mmol) obtained in the previous stage in THF (100 mL)/water (100mL) was prepared under nitrogen, a methanol solution of lithium hydroxide (2.91g, 121mmol) was slowly added dropwise at room temperature, the temperature was maintained, and stirring was performed for 24 hours. The reaction solution was cooled to 5 ℃, 1N — HCl solution was slowly added until pH became 4, poured into water and extracted with diethyl ether (300mL), and washed with water twice. The organic phase was concentrated, and the residue was purified by silica gel column chromatography (developing solvent: toluene/ethyl acetate 2/1) to obtain compound (105) (8.50g, 28.9mmol) as a white crystal.

(fourth stage) Synthesis of Compound (K101)

A solution of phenol derivative (106) (7.37g, 29.9mmol) in dichloromethane (5mL) was cooled to-10 ℃ under nitrogen, N' -dicyclohexylcarbodiimide (6.17g, 29.9mmol), 4-dimethylaminopyridine (1.00g, 8.15mmol) and carboxylic acid derivative (105) (4.00g, 13.6mmol) obtained in the previous stage were added, and the mixture was stirred at room temperature for 5 hours. The reaction solution was filtered, poured into water, and dichloromethane (50mL) was added thereto, followed by washing twice with sodium bicarbonate and twice with water. Then, the organic phase was concentrated, and the residue was purified by silica gel column chromatography (developing solvent: toluene) to obtain compound (K101) (6.30g, 8.39 mmol). The melting point of the compound was 85 ℃.

¹H-NMR(CDCl₃，ppm)：0.932-0.985(6H,t),1.37-1.43(8H,m),1.66-1.71(4H,m),2.66-2.69(4H,t),3.93(2H,s),5.07(2H,s),7.04-7.07(4H,d),7.24-7.31(8H,m),7.46-7.51(8H,m),7.58-7.60(4H,d).

[ example 2]

< Synthesis of Compound (K102) >

[ solution 47]

(in the compound (K1-1), Rodk1 ═ Rod1-1G, nk1 ═ nk2 ═ 0, and R^k2＝C₅H₁₁A compound of (1)

By the same method as in example 1, using the following compound (107) instead of the compound (106), the compound (K102) (2.40g, 2.66mmol) was obtained. The melting point of the compound was 182 ℃.

[ solution 48]

¹H-NMR(CDCl₃，ppm)：0.885-0.914(6H,t),1.02-1.10(4H,m),1.20-1.35(18H,m),1.45-1.55(4H,m),1.86-1.93(8H,m),2.47-2.58(2H,tt),3.88(2H,s),5.03(2H,s),7.00-7.02(4H,d),7.21-7.22(4H,m),7.26-7.28(4H,d),7.42-7.48(8H,m),7.53-7.55(4H,d).

[ example 3]

< Synthesis of Compound (K103) >

[ solution 49]

(in the compound (K1-1), Rodk1 ═ Rod1-1D, nk1 ═ nk2 ═ 0, and R is^k2＝C₅H₁₁A compound of (1)

Compound (K103) (9.04g, 12.0mmol) was obtained by the same method as in example 1, using the following compound (108) in place of compound (106). The compound is in an amorphous state at normal temperature.

[ solution 50]

¹H-NMR(CDCl₃，ppm)：0.879-0.907(6H,t),0.990-1.06(4H,m),1.18-1.33(18H,m),1.38-1.43(4H,m),1.84-1.86(8H,d),2.40-2.48(2H,tt),3.82(2H,s),4.98(2H,s),6.84-6.86(4H,d),7.16-7.20(8H,m),7.38-7.40(2H,d),7.42-7.43(2H,m).

[ example 4-1]

A liquid crystal composition NLC-A was prepared by mixing the liquid crystal compounds shown in the following figure in the following proportions.

[ solution 51]

Liquid Crystal composition NLC-A

[ solution 52]

The phase transition temperature (DEG C) of the liquid crystal composition NLC-A is N79.7I, and the average refractive index is more than N and more than 1.56.

In a liquid crystal composition NLC-A (98.0% by weight), the compound (K101) (2.00% by weight) obtained in example 1 was dissolved by heating at 100 ℃ to obtain a liquid crystal composition CLC-A1. The phase transition temperature (DEG C) of the liquid crystal composition CLC-A1 was N79.1I.

At this time, the heating time required to obtain a completely dissolved liquid crystal composition CLC-A1 was 2 minutes. As a result, it was found that the compound (K101) exhibited very high solubility.

The selective reflection wavelength (. lamda.) of the liquid crystal composition CLC-A1 was 484.0(nm), and the HTP value of the compound (K101) calculated from these values was 161 (. mu.m)^-1). Further, the VHR of the liquid crystal composition CLC-A1 was measured, and it was 96.1%. As a result, it was found that the composition CLC-A1 showed a high voltage holding ratio.

[ example 4-2]

A liquid crystal composition NLC-B was prepared by mixing the liquid crystal compounds shown in the following figure in the following proportions.

[ Hua 53]

Liquid Crystal composition NLC-B

[ solution 54]

The phase transition temperature (DEG C) of the liquid crystal composition NLC-B is N87.9I, and the average refractive index is more than N and more than 1.56.

In a liquid crystal composition NLC-B (95.2% by weight), the compound (K101) (4.80% by weight) obtained in example 1 was completely dissolved by heating and stirring at 100 ℃ for 2 minutes to obtain a liquid crystal composition CLC-B1.

The phase transition temperature (DEG C) of the liquid crystal composition CLC-B1 was N79.1 BP 79.2I.

[ examples 4 to 3]

Preparation of monomer/liquid Crystal mixtures

A liquid crystal composition MLC-B1, which was a mixture of a liquid crystal composition CLC-B189.2 wt%, n-hexadecyl acrylate (C16A)5.4 wt%, compound (MC3-12)5.4 wt%, and 2,2' -dimethoxyphenylacetophenone 0.4 wt% as a photopolymerization initiator, was prepared as a mixture of the liquid crystal composition and a polymerizable monomer. The liquid crystal composition MLC-B1 has a phase transition temperature (DEG C) of 51.1BP 54.6I, I53.3.3 BP 49.7N.

[ solution 55]

·C16A

·MC3-12

[ examples 4 to 4]

Preparation of polymer/liquid crystal composite material

The liquid crystal composition MLC-B1 was sandwiched between a comb-shaped electrode substrate to which no alignment treatment was applied and an opposing glass substrate (no electrode was applied) (cell thickness: 8 μm), and the obtained cell was heated to a blue phase at 52.0 ℃. In this state, ultraviolet light (ultraviolet light intensity of 23 mWcm) was irradiated^-2(365nm)) for 1 minute.

The polymer/liquid crystal composite material PSBP-B1 thus obtained maintained an optically isotropic liquid crystal phase even when cooled to room temperature.

As shown in fig. 1, the electrodes of the comb-shaped electrode substrate are arranged such that an electrode 1 extending in the right direction from the left connecting electrode portion and an electrode 2 extending in the left direction from the right connecting electrode portion are alternately arranged. Therefore, when a potential difference exists between the electrode 1 and the electrode 2, focusing on one electrode on the comb-shaped electrode substrate as shown in fig. 1 can provide a state in which an electric field exists in both the upward direction and the downward direction on the drawing.

[ examples 4 to 5]

The cell holding the polymer/liquid crystal composite material PSBP-B1 obtained in example 4-4 was set in an optical system shown in fig. 2, and the electrooptical characteristics were measured. The measurement optical system shown in fig. 2 includes a light source 3, a polarizer 4, a comb electrode 5, an analyzer 6, and a light receiver (photo receptor) 7. As the light source 3, a white light source manufactured by a polarizing microscope (Eclipse LV100POL) was used, and the cell was installed in an optical system such that an incident angle to the cell was perpendicular to a cell surface and a linear direction of the comb electrode 5 was 45 ° to each of a Polarizer (Polarizer)4 and an Analyzer (Analyzer) 6. The relationship between the applied voltage and the transmittance was examined at room temperature. When a square wave of 68.4V was applied, the transmittance was 89.7%, and the transmitted light intensity was saturated. The contrast ratio was 1614 and showed a very high value.

[ example 5-1]

In a liquid crystal composition NLC-a (98.0 wt%), the compound (K102) (2.00 wt%) obtained in example 2 was dissolved by heating at 100 ℃ to obtain a liquid crystal composition CLC-a 2. The phase transition temperature (DEG C) of the liquid crystal composition CLC-A2 was N79.1I.

At this time, the heating time required to obtain a completely dissolved liquid crystal composition CLC-A2 was 3 minutes. As a result, it was found that the compound (K102) exhibited very high solubility.

The selective reflection wavelength (. lamda.) of the liquid crystal composition CLC-A2 was 560 (nm). The HTP of the compound (K102) calculated from these values was 139 (. mu.m)^-1). Further, the VHR of the liquid crystal composition CLC-A2 was measured to be 95.6%. As a result, it was found that the composition CLC-A2 showed a high voltage holding ratio.

[ examples 5-2]

In a liquid crystal composition NLC-B (95.2% by weight), the compound (K102) (4.80% by weight) obtained in example 2 was completely dissolved by heating and stirring at 100 ℃ for 2 minutes to obtain a liquid crystal composition CLC-B2.

The phase transition temperature (DEG C) of the liquid crystal composition CLC-B2 was N.83.5 BP 83.7I.

[ examples 5 to 3]

Preparation of monomer/liquid Crystal mixtures

A liquid crystal composition MLC-B2 obtained by mixing a liquid crystal composition CLC-B289.2 wt%, n-hexadecyl acrylate (C16A)5.4 wt%, a compound (MC3-12)5.4 wt%, and 2,2' -dimethoxyphenylacetophenone as a photopolymerization initiator 0.4 wt% was prepared as a mixture of the liquid crystal composition and a polymerizable monomer. The liquid crystal composition MLC-B2 has a phase transition temperature (DEG C) of 55.4BP 55.5I, I55.6.6 BP 54.7N.

[ examples 5 to 4]

Preparation of polymer/liquid crystal composite material

The liquid crystal composition MLC-B2 was sandwiched between a comb-shaped electrode substrate which had not been subjected to alignment treatment and a counter glass substrate (no electrode was provided) (cell thickness: MLC-B2)8 μm) and the unit obtained was heated to a blue phase at 55.4 ℃. In this state, ultraviolet light (ultraviolet light intensity of 23 mWcm) was irradiated^-2(365nm)) for 1 minute.

The polymer/liquid crystal composite material PSBP-B2 thus obtained maintained an optically isotropic liquid crystal phase even when cooled to room temperature.

[ examples 5 to 5]

The cell holding the polymer/liquid crystal composite material PSBP-B2 obtained in example 5-4 was set in an optical system shown in fig. 2, and the electrooptical characteristics were measured. As a light source, a white light source using a polarizing microscope (Eclipse LV100POL, manufactured by Nikon (Nikon)) was used, and the cell was installed in an optical system such that an incident angle to the cell was perpendicular to a cell plane and a line direction of the comb-shaped electrode was 45 ° with respect to a polarizer and an analyzer polarizing plate, respectively. The relationship between the applied voltage and the transmittance was examined at room temperature. When a rectangular wave of 59.5V was applied, the transmittance was 88.9%, and the transmitted light intensity was saturated. The contrast ratio was 1656 and showed a very high value.

[ example 6-1]

The liquid crystal composition NLC-C was prepared by mixing the liquid crystal compounds shown in the following figures in the following ratios.

[ solution 56]

Liquid Crystal composition NLC-C

The phase transition temperature (DEG C) of the liquid crystal composition NLC-C is N79.9I, and the average refractive index is more than N and more than 1.60.

In a liquid crystal composition NLC-C (95.8% by weight), the compound (K101) (4.2% by weight) obtained in example 1 was completely dissolved by heating and stirring at 100 ℃ for 2 minutes to obtain a liquid crystal composition CLC-C1.

The phase transition temperature (DEG C) of the liquid crystal composition CLC-C1 was N75.9I. In addition, the liquid crystal composition CLC-C1 had a helical pitch of 0.29 μm and a VHR of 99.1%. As a result, it was found that the composition CLC-C1 exhibited a high voltage holding ratio.

[ example 6-2]

Preparation of monomer/liquid Crystal mixtures

A liquid crystal composition MLC-C1 was prepared by mixing the compound (K101) (0.9 wt%) obtained in example 1, the compound (MC2-04), and 0.3 wt% of 2,2' -dimethoxyphenylacetophenone as a photopolymerization initiator with the liquid crystal composition NLC-C (92.9 wt%).

[ solution 57]

·MC2-04

[ examples 6 to 3]

Preparation of polymer/liquid crystal composite material

The liquid crystal composition MLC-C1 was sandwiched between two glass substrates provided with electrodes of a transparent conductive film (cell thickness: 10 μm) which were not subjected to alignment treatment, and the obtained cell was heated until MLC-04 became an isotropic phase. In this state, ultraviolet light (ultraviolet light intensity of 18 mWcm) was irradiated^-2(365nm)) for 1 minute.

The polymer/liquid crystal composite material PDLC-C1 thus obtained maintained a chiral nematic phase even when cooled to room temperature.

[ examples 6 to 4]

The cell holding the polymer/liquid crystal composite PDLC-C1 obtained in example 6-3 was set in an optical system, and the electrooptical characteristics were measured. A white light source using a polarization microscope (manufactured by Nikon (Nikon), Eclipse (Eclipse) LV100POL) was used as the light source, and was provided in the optical system so that the incident angle to the cell was perpendicular to the cell surface. The relationship between the applied voltage and the transmittance was examined at room temperature. When a voltage of 20V was applied, it was confirmed that the polymer/liquid crystal composite PDLC-C1 was driven in the normal mode. When a voltage of 10V was applied across the electrodes of the polymer/liquid crystal composite PDLC-C1, the transmitted light intensity was 96.9%, and when a voltage of 22V was applied, the transmitted light intensity was 10.0%, and a liquid crystal device that was driven at a low voltage and had a high contrast could be obtained.

[ example 7-1]

In a liquid crystal composition NLC-C (95.8% by weight), the compound (K102) (4.2% by weight) obtained in example 2 was completely dissolved by heating and stirring at 100 ℃ for 3 minutes to obtain a liquid crystal composition CLC-C2.

The phase transition temperature (DEG C) of the liquid crystal composition CLC-C2 is N × 82.5I. In addition, the liquid crystal composition CLC-C2 had a helical pitch of 0.33. mu.m, and a VHR of 99.2%. As a result, it was found that the composition CLC-C2 exhibited a high voltage holding ratio.

[ example 7-2]

Preparation of monomer/liquid Crystal mixtures

A liquid crystal composition MLC-C2 was prepared by mixing the compound (K102) (0.9 wt%) obtained in example 2, the compound (MC2-04), and 2,2' -dimethoxyphenylacetophenone as a photopolymerization initiator in an amount of 5.90 wt% with the liquid crystal composition NLC-C (92.9 wt%).

[ examples 7 to 3]

Preparation of polymer/liquid crystal composite material

The liquid crystal composition MLC-C2 was sandwiched between two glass substrates provided with electrodes of a transparent conductive film (cell thickness: 10 μm) which were not subjected to alignment treatment, and the obtained cell was heated until MLC-04 became an isotropic phase. In this state, ultraviolet light (ultraviolet light intensity of 18 mWcm) was irradiated^-2(365nm)) for 1 minute.

The polymer/liquid crystal composite material PDLC-C2 thus obtained maintained a chiral nematic phase even when cooled to room temperature.

[ examples 7 to 4]

The cell holding the polymer/liquid crystal composite PDLC-C2 obtained in example 7-3 was set in an optical system, and the electrooptical characteristics were measured. A white light source using a polarization microscope (manufactured by Nikon (Nikon), Eclipse (Eclipse) LV100POL) was used as the light source, and was provided in the optical system so that the incident angle to the cell was perpendicular to the cell surface. The relationship between the applied voltage and the transmittance was examined at room temperature. When a voltage of 20V was applied, it was confirmed that the polymer/liquid crystal composite PDLC-C2 was driven in the normal mode. When a voltage of 10V was applied across the electrodes of the polymer/liquid crystal composite PDLC-C2, the transmitted light intensity was 91.1%, and when a voltage of 18V was applied, the transmitted light intensity was 10.0%, and a liquid crystal device that was driven at a low voltage and had a high contrast could be obtained.

[ example 8-1]

In a liquid crystal composition NLC-C (95.8% by weight), the compound (K103) (4.2% by weight) obtained in example 3 was completely dissolved by heating and stirring at 100 ℃ for 2 minutes to obtain a liquid crystal composition CLC-C3.

The phase transition temperature (DEG C) of the liquid crystal composition CLC-C3 was N75.4I. The liquid crystal composition CLC-C3 had a helical pitch of 0.31 μm and a VHR of 98.0%. As a result, it was found that the composition CLC-C3 exhibited a high voltage holding ratio.

[ example 8-2]

Preparation of monomer/liquid Crystal mixtures

A liquid crystal composition MLC-C3 was prepared by mixing the compound (K103) (0.9 wt%) obtained in example 3, the compound (MC2-04)5.90 wt%, and 2,2' -dimethoxyphenylacetophenone 0.3 wt% as a photopolymerization initiator with the liquid crystal composition NLC-C (92.9 wt%).

[ examples 8 to 3]

Preparation of polymer/liquid crystal composite material

The liquid crystal composition MLC-C3 was sandwiched between two glass substrates provided with electrodes of a transparent conductive film (cell thickness: 10 μm) which were not subjected to alignment treatment, and the obtained cell was heated until MLC-04 became an isotropic phase. In this state, ultraviolet light (ultraviolet light intensity of 18 mWcm) was irradiated^-2(365nm)) for 1 minute.

The polymer/liquid crystal composite material PDLC-C3 thus obtained maintained a chiral nematic phase even when cooled to room temperature.

[ examples 8 to 4]

The cell holding the polymer/liquid crystal composite PDLC-C3 obtained in example 8-3 was set in an optical system, and the electrooptical characteristics were measured. As a light source, a white light source of a polarization microscope (Eclipse LV100POL, manufactured by Nikon) was used, and the cell was disposed in the optical system so that an incident angle to the cell was perpendicular to the cell surface. The relationship between the applied voltage and the transmittance was examined at room temperature. When a voltage of 20V was applied, it was confirmed that the polymer/liquid crystal composite PDLC-C3 was driven in the normal mode. When a voltage of 10V was applied across the electrodes of the polymer/liquid crystal composite PDLC-C3, the transmitted light intensity was 91.0%, and when a voltage of 20V was applied, the transmitted light intensity was 10.0%, and a liquid crystal device that was driven at a low voltage and had a high contrast could be obtained.

Industrial applicability

Examples of effective uses of the present invention include liquid crystal devices such as display devices using a polymer/liquid crystal composite material, and light control glasses.

Description of the symbols

1: electrode 1

2: electrode 2

3: light source

4: polarizer (polarizing plate) (Polarizer)

5: comb-shaped electrode unit

6: polarization Analyzer (polarizer) (Analyzer)

7: light receiver (Phototefector)

Claims

1. A liquid crystal composition containing at least one of chiral compounds represented by formula (K1) as a chiral component (K) and at least one of achiral compounds represented by formula (1-A) or formula (1-B) as an achiral component (T).

[ solution 1]

Chiral component (K)

Rod^k1：

(in the formula (K1),

nk1 and nk2 are each independently an integer of 0 to 4,

Rod^k1is part of the structural formula (Rod1),

in the partial structural formula (Rod1),

mk1 and mk2 are each independently an integer of 0 or 1.

In addition, 0 to 4R are connected in the ring structure shown below^k1Partial structure (X1) andin the partial structure (X2), 0 to 4 of the hydrogens forming the ring structure can be substituted by R^k1Substitution).

[ solution 2]

[ solution 3]

Achiral component (T)

(in the formulae (1-A) and (1-B),

R¹¹and R¹²Each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, at least one-CH group being present in the alkyl group and the alkenyl group₂-may be substituted by-O-, but two consecutive-CHs₂-is not substituted by-O-, in which groups at least one hydrogen may be substituted by halogen;

L¹¹And L¹²Each independently is hydrogen or fluorine;

S¹¹is hydrogen or methyl;

m and n are each independently 0 or 1).

2. The liquid crystal composition according to claim 1, wherein the chiral compound represented by formula (K1) is a chiral compound represented by formula (K1-1).

[ solution 4]

Rod^k1：

(in the formula (K1-1),

nk1 and nk2 are each independently an integer of 0 to 4,

mk1 and mk2 are each independently an integer of 0 or 1.

R is bonded to a ring structure shown below^k1In the partial structure (X1) and the partial structure (X2), 0 to 4 hydrogens of the hydrogens forming the ring structure can be replaced by R^k1Substituted)

[ solution 5]

3. The liquid crystal composition according to claim 2, wherein in formula (K1-1),

nk1 and nk2 are each independently an integer of 0 to 4,

Rod^k1is a partial structural formula (R) shown belowod1-1A) -partial structural formula (Rod1-1H) and partial structural formula (Rod1-2A) -partial structural formula (Rod 1-2H).

[ solution 6]

Rod^k1：

[ solution 7]

further, the partial structure (X3) shown below in which (F) is bonded to a1, 4-phenylene group represents a1, 4-phenylene group in which one or two hydrogens may be substituted with fluorine,

[ solution 8]

4. The liquid crystal composition according to any one of claims 1 to 3, wherein the achiral compound represented by formula (1-A) is any one of achiral compounds represented by formulae (1-A-01) to (1-A-22).

[ solution 9]

[ solution 10]

[ solution 11]

In the formulae (1-A-01) to (1-A-22),

X¹¹independently of one another, fluorine, chlorine, -CF₃or-OCF₃；

(F) Is hydrogen or fluorine.

5. The liquid crystal composition according to any one of claims 1 to 3, wherein the achiral compound represented by formula (1-B) is any one of achiral compounds represented by formulae (1-B-01) to (1-B-22).

[ solution 12]

[ solution 13]

In the formulae (1-B-01) to (1-B-22),

(F) is hydrogen or fluorine.

6. The liquid crystal composition according to any one of claims 1 to 5, wherein the content of the chiral component (K) in the liquid crystal composition is 0.1 to 30% by weight.

7. The liquid crystal composition according to any one of claims 1 to 6, wherein the content of the compound represented by formula (1-A) or formula (1-B) in the achiral component (T) is 50 to 100% by weight.

8. The liquid crystal composition according to any one of claims 1 to 6, wherein the content of the compound represented by formula (1-A) in the achiral component (T) is 50 to 100% by weight, and shows an optically isotropic liquid crystal phase.

9. The liquid crystal composition according to any one of claims 1 to 8, wherein at least one of chiral compounds represented by formulae (K2) to (K8) is further contained in the chiral component (K).

[ solution 14]

In the formulae (K2) to (K8), R^KEach independently represents hydrogen, halogen, -C ≡ N, -N ═ C ═ O, -N ═ C ═ S, or alkyl having 1 to 20 carbon atoms, and at least one-CH group in the alkyl groups₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, among the alkyl groupsAt least one hydrogen may be substituted with a halogen;

mK is an integer of 1 to 4, respectively).

10. A monomer/liquid crystal mixture comprising the liquid crystal composition of any one of claims 1 to 9, and a polymerizable monomer.

11. The monomer/liquid crystal mixture according to claim 10, exhibiting a chiral nematic phase in a temperature range of at least 1 ℃ or more in-20 ℃ to 70 ℃, and a helical pitch of 700nm or less in at least a part of the temperature range.

12. The monomer/liquid crystal mixture of claim 10 wherein the liquid crystal composition is a liquid crystal composition having an optically isotropic liquid crystal phase.

13. The monomer/liquid crystal mixture according to any one of claims 10 to 12, wherein the content of the polymerizable monomer is in the range of 0.1 to 50% by weight with respect to the total amount of the monomer/liquid crystal mixture.

14. A polymer/liquid crystal composite material which is obtained by polymerizing the monomer/liquid crystal mixture according to claim 10 in a non-liquid crystal isotropic phase or an optically isotropic liquid crystal phase and which is used for a liquid crystal cell driven in the optically isotropic liquid crystal phase.

15. A polymer/liquid crystal composite material which is obtained by polymerizing the monomer/liquid crystal mixture according to claim 10 and is used for a light scattering type liquid crystal cell driven by a chiral nematic phase.

16. A liquid crystal cell comprising: a pair of substrates having electrodes; a light adjusting layer sandwiched between the pair of substrates; and an electric field applying member for applying an electric field to the dimming layer via the electrode,

at least one of the pair of substrates is transparent, and the light modulation layer comprises the polymer/liquid crystal composite material according to claim 14 or 15.

17. The liquid crystal element according to claim 16, wherein the polymer/liquid crystal composite exhibits a chiral nematic phase and constitutes a light scattering type liquid crystal element.

18. The liquid crystal element according to claim 16 or 17, wherein the content of the polymer in the polymer/liquid crystal composite material is in a range of 0.1 to 50 wt%.

19. A chiral compound is represented by the following formula (K101), formula (K102), or formula (K103).

[ solution 15]

(K101)

(K102)

(K103)

Here, (R) represents a palm character.