Liquid crystal composition for light conversion element, mixture, polymer/liquid crystal composite material, element, and laser radar

文档序号：1717309 发布日期：2019-12-17 浏览：17次中文

阅读说明：本技术 用于光转换元件的液晶组合物、混合物、高分子/液晶复合材料、元件及激光雷达 (Liquid crystal composition for light conversion element, mixture, polymer/liquid crystal composite material, element, and laser radar ) 是由山本真一冈部英二于 2019-06-10 设计创作，主要内容包括：使用向列液晶介质的转换元件的响应时间长,因此每固定时间内的控制次数有限制。本发明提供一种能够通过使用具有光学各向同性相的液晶组合物进行高速偏光控制的元件。本发明提供一种包含所述液晶组合物以及聚合性单体的混合物,一种根据所述的混合物聚合而获得的高分子/液晶复合材料,一种包含所述液晶组合物、或者所述的高分子/液晶复合材料的元件,以及一种包含所述的元件的激光雷达。(The response time of a switching element using a nematic liquid crystal medium is long, and therefore the number of controls per fixed time is limited. The invention provides an element capable of performing high-speed polarization control by using a liquid crystal composition having an optically isotropic phase. The present invention provides a mixture comprising the liquid crystal composition and a polymerizable monomer, a polymer/liquid crystal composite material obtained by polymerizing the mixture, an element comprising the liquid crystal composition or the polymer/liquid crystal composite material, and a lidar comprising the element.)

1. A liquid crystal composition containing an achiral component T and having a liquid crystal phase exhibiting optical isotropy, for use in light conversion utilizing electric-field-induced birefringence to control retardation.

2. The liquid crystal composition according to claim 1, which is used for photoconversion in which retardation is controlled from 0 to λ/2 by applying a voltage.

3. The liquid crystal composition according to claim 1, which is used for switching between right circular polarization and left circular polarization.

4. The liquid crystal composition according to any one of claims 1 to 3, wherein the achiral component T contains at least one compound 1 represented by formula (1),

In the formula, R¹¹Hydrogen or C1-20 alkyl, at least one-CH in the alkyl₂-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; r¹²Is hydrogen, halogen, -C ≡ N, -N ═ C ═ O, -N ═ C ═ S, -CF₃、-OCF₃Or an alkyl group having 1 to 3 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, at least one of the alkyl groups may be substituted by halogen, at least one-CH of the alkyl groups may be substituted by halogen₃May be substituted by-C ≡ N; ring A¹¹Ring A¹⁵Each independently a 5-to 8-membered ring or a condensed ring having 9 or more carbon atoms, wherein at least one hydrogen in the ring may be substituted with a halogen, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group; at least one-CH of said alkyl group or said halogenated alkyl group₂-may be substituted by-O-, -S-, or-NH-, at least one-CH in said ring₂-may be substituted by-O-, -S-, or-NH-, at least one-CH ═ in the ring may be substituted by-N ═ in the ring; z¹¹～Z¹⁴Each independently represents a single bond or an alkylene group having 1 to 8 carbon atoms, at least one-CH group being contained in the alkylene group₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N ═ N-, -CH ═ N-, -N ═ CH-, -N- (O) -N-, -N ═ N- (O) -, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, at least one hydrogen of said alkylene groups may be substituted by halogen; n is¹¹～n¹³Each independently is 0 or 1.

5. the liquid crystal composition according to claim 4, wherein in formula (1), n¹¹+n¹²+n¹³Is 2 or 3, A¹¹～A¹⁴Selected from the group consisting of the following groups (A-1) to (A-10)¹⁵Selected from the group consisting of the groups represented by (A-1) to (A-3), and further A¹¹～A¹⁵The total number of halogen elements in (1) is 6 or more,

6. The liquid crystal composition according to any one of claims 1 to 3, wherein the achiral component T contains at least one compound 2 represented by formula (2),

In the formula (2), R²Is hydrogen, alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, alkynyl group having 2 to 20 carbon atoms, alkoxy group having 1 to 19 carbon atoms or alkoxyalkyl group having 1 to 20 carbon atoms in total, at least one-CH in the alkyl groups₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by fluoro or chloro, wherein, at R²wherein-O-and-CH-and-CO-and-CH-are not contiguous;

Z¹～Z³Each independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-；

L¹～L⁸Each independently is hydrogen or fluorine;

n¹And n²Each independently is 0 or 1;

X²Is hydrogen, halogen, -SF₅Or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be taken via-CH ═ CH-, -CF ═ CF-or-C ≡ C-In the alkyl group, at least one-CH in the alkyl group₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂-at least one hydrogen of the radicals substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted by fluorine or chlorine, where, in X²In which-O-and-CH-and-CO-and-CH-are not contiguous.

7. The liquid crystal composition according to claim 6, wherein the achiral component T comprises at least one compound 3 represented by formula (3),

In the formula (3), R³Is hydrogen, alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, alkynyl group having 2 to 20 carbon atoms, alkoxy group having 1 to 19 carbon atoms or alkoxyalkyl group having 1 to 20 carbon atoms in total, at least one-CH in the alkyl groups₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by fluoro or chloro, wherein, at R³wherein-O-and-CH-and-CO-and-CH-are not contiguous;

Z³¹～Z³⁴Each independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-；

L³¹～L³⁶Each independently is hydrogen or fluorine;

X³Is hydrogen, halogen, -SF₅or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in which alkyl at least one-CH of said alkyl groups₂-CH in a-O-, -S-, -COO-or-OCO-substituted radical, or in at least one of said alkyl radicals₂-CH₂-via-CH ═ CH-, -CF ═ CF-or-C.ident.C-substituted, wherein at least one hydrogen may be substituted by fluorine or chlorine, in which case in X³wherein-O-and-CH-and-CO-and-CH-are not contiguous;

n³¹And n³²each independently is 0 or 1.

8. The liquid crystal composition according to claim 7, wherein the compound 2 is contained in an amount of 25 to 90% by weight in total and the compound 3 is contained in an amount of 5 to 65% by weight in total, relative to the total weight of the achiral component T.

9. A liquid crystal composition according to any one of claims 1 to 3, comprising a chiral agent.

10. The liquid crystal composition according to any one of claims 1 to 3, comprising one or more compounds selected from the group consisting of antioxidants and UV absorbers.

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

12. A polymer/liquid crystal composite material used in an element driven with a liquid crystal phase exhibiting optical isotropy, and obtained by polymerizing the mixture according to claim 11.

13. The polymer/liquid crystal composite according to claim 12, which is obtained by polymerizing the mixture in a temperature range in which a liquid crystal phase of a non-liquid crystal isotropic phase or an optically isotropic phase is exhibited.

14. An element comprising the liquid crystal composition according to any one of claims 1 to 10, or the mixture according to claim 11, or the polymer/liquid crystal composite according to claim 12 or 13.

15. The element according to claim 14, which can be used with respect to light in the near infrared range of 0.72 μm to 2.5 μm.

16. The element according to claim 14, which can be used with respect to light in a millimeter wave range of 1mm to 10 mm.

17. a lidar comprising at least one element according to claim 14.

Technical Field

the present invention relates to a mixture of a liquid crystal composition and a liquid crystal medium (liquid crystal composition, polymer/liquid crystal composite material, or the like) exhibiting an optically isotropic liquid crystal phase, a polymerizable monomer, or the like, used in a light conversion element, for example, in Laser Imaging Detection and Ranging (LIDAR), and an element using the same.

Background

The optical conversion element is an element that switches an optical path or turns on/off (on/off), and is of a mechanical type, an electronic type, a full light type, or the like. The mechanical type is a type in which a prism (prism), a mirror (mirror), or an optical fiber is mechanically moved, and the electronic type is a type using an electro-optical effect, a magneto-optical effect, a thermo-optical effect, or a semiconductor gate. The full light type uses a nonlinear refractive index change, and a system using a liquid crystal medium exhibiting an isotropic liquid crystal phase corresponds to the full light type. The light conversion element is preferably capable of controlling light of a wide range of wavelengths, and more preferably capable of controlling light of visible rays (0.38 to 0.78 μm), near infrared rays (0.72 to 2.5 μm), or millimeter waves (1 to 10 mm).

Laser radar (LIDAR) is one of remote sensing technologies for measuring the distance, direction, and the like of an object from reflected light, and uses short laser light having a wavelength in the near infrared range (0.72 μm to 2.5 μm). As for polarization control, Mechanical devices such as Micro Electro Mechanical Systems (MEMS) have been studied, but there are many problems that it is difficult to control the guide angle, and the movable portion is Mechanical and therefore has poor durability.

The polarization control by the element using the liquid crystal medium is performed by the electro-optical response of the liquid crystal medium. The incident light is converted into elliptically polarized light, linearly polarized light, circularly polarized light, or the like. By using an element in which a liquid crystal medium is used, the element can be used as a light conversion element which is electrically operated without mechanical driving.

In a device using a liquid crystal medium for polarization control, a nematic liquid crystal medium is used and the response time is long, so that there is a problem that the number of controls per fixed time is limited. As a liquid crystal medium which can be controlled in polarization by electro-optical response similarly to a nematic liquid crystal medium, a blue phase liquid crystal medium which is one of optically isotropic liquid crystal phases is known. Heretofore, a tunable filter, a wavefront control (wavefront control) element, a liquid crystal lens, an aberration correction element, an aperture control element, an optical head device, and the like, which utilize electric field induced birefringence, have been proposed (patent documents 1 to 4).

[ Prior art documents ]

[ patent document ]

[ patent document 1] Japanese patent laid-open No. 2005-157109

[ patent document 2] International publication No. 2005/80529

[ patent document 3] Japanese patent laid-open No. 2006-

[ patent document 4] International publication No. 2018-003658

Disclosure of Invention

[ problems to be solved by the invention ]

As described above, there are problems that control of the guide angle is difficult and durability is poor in a mechanical element for which polarization control use has been studied. In addition, since the response time of an element using a nematic liquid crystal medium is long, the number of times of control per fixed time is limited.

[ means for solving problems ]

The inventors have made an intensive study and, as a result, have found that: an element using a liquid crystal medium exhibiting an optically isotropic liquid crystal phase, particularly a blue phase liquid crystal medium, can be preferably used in polarization control applications, thereby completing the present invention.

It is known that the response time of an element using a blue phase liquid crystal medium is short (high-speed response). The reason for this is that: when no electric field is applied, the blue phase liquid crystal medium induces birefringence using the electro-optic kerr effect proportional to the square of the applied electric field when the electric field is applied, and exhibits optical anisotropy.

In the present invention, a blue phase liquid crystal medium is used as a liquid crystal medium for a light conversion element to solve the above problems. The blue phase liquid crystalline medium can be converted from an optically isotropic state to an anisotropic state at high speed. That is, the polarization control can be performed at high speed by the electric operation. For example, the blue phase liquid crystal medium has a characteristic of inducing birefringence of a half wavelength (λ/2) with respect to the wavelength of an incident light source by electric operation, and can reverse the polarization direction of the incident light toward the right or left circle to be converted to the left or right. Regarding the time taken for the conversion, if it is the area showing the electro-optical kerr effect, it is of the order of sub-milliseconds, and is characterized in that: in principle, the difference in response time between when the electric field is applied and when the electric field is removed does not occur.

The present invention provides, for example, a liquid crystal medium (a liquid crystal composition, a polymer/liquid crystal composite material, or the like), a mixture of a polymerizable monomer or the like and a liquid crystal composition, and a light conversion element containing a liquid crystal medium or the like.

The present invention includes the following items.

2. The liquid crystal composition according to item 1, which is used for light conversion in which retardation is controlled from 0 to λ/2 by applying a voltage.

3. The liquid crystal composition according to item 1, which is used to switch right circular polarization from left circular polarization.

4. The liquid crystal composition according to any one of items 1 to 3, wherein the achiral component T contains at least one compound 1 represented by formula (1).

In the formula, R¹¹Hydrogen or C1-20 alkyl, at least one-CH in the alkyl₂-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; r¹²Is hydrogen, halogen, -C ≡ N, -N ═ C ═ O, -N ═ C ═ S, -CF₃、-OCF₃Or an alkyl group having 1 to 3 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, at least one of the alkyl groups may be substituted by halogen, at least one-CH of the alkyl groups may be substituted by halogen₃May be substituted by-C ≡ N; ring A¹¹Ring A¹⁵Each independently represents a 5-to 8-membered ring or a condensed ring having 9 or more carbon atoms, and at least one hydrogen in the ring may be substituted with a halogen, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group. At least one-CH of said alkyl group or said halogenated alkyl group₂-may be substituted by-O-, -S-, or-NH-, at least one-CH in said ring₂-may be substituted by-O-, -S-, or-NH-, at least one-CH ═ in the ring may be substituted by-N ═ in the ring; z¹¹～Z¹⁴Each independently represents a single bond or an alkylene group having 1 to 8 carbon atoms, at least one-CH group being contained in the alkylene group₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N ═ N-, -CH ═ N-, -N ═ CH-, -N- (O) -N-, -N ═ N- (O) -, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, at least one hydrogen of said alkylene groups may be substituted by halogen; n is¹¹～n¹³Each independently is 0 or 1.

5. The liquid crystal composition according to item 4, wherein, in formula (1), n¹¹+n¹²+n¹³Is 2 or 3, A¹¹～A¹⁴Selected from the group consisting of the following groups (A-1) to (A-10)¹⁵Selected from the group consisting of the groups represented by (A-1) to (A-3), and further A¹¹～A¹⁵The total number of halogen elements in (1) is 6 or more.

6. The liquid crystal composition according to any one of items 1 to 5, wherein the achiral component T contains at least one compound 2 represented by formula (2).

Z¹～Z³Each independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-；

L¹～L⁸Each independently is hydrogen or fluorine;

n¹And n²Each independently is 0 or 1;

X²Is hydrogen, halogen, -SF₅or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in which alkyl at least one-CH of said alkyl groups₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂-at least one hydrogen of the radicals substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted by fluorine or chlorine, where, in X²In which-O-and-CH-and-CO-and-CH-are not contiguous.

7. The liquid crystal composition according to any one of items 1 to 6, wherein the achiral component T contains at least one compound 3 represented by formula (3).

in the formula (3), R³Is hydrogen, alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, alkynyl group having 2 to 20 carbon atoms, alkoxy group having 1 to 19 carbon atoms or alkoxyalkyl group having 1 to 20 carbon atoms in total, at least one-CH in the alkyl groups₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by fluoro or chloro, wherein, at R³wherein-O-and-CH-and-CO-and-CH-are not contiguous;

Z³¹～Z³⁴Each independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-；

L³¹～L³⁶Each independently is hydrogen or fluorine;

X³Is hydrogen, halogen, -SF₅Or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in which alkyl at least one-CH of said alkyl groups₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂-at least one hydrogen of the radicals substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted by fluorine or chlorine, where, in X³wherein-O-and-CH-and-CO-and-CH-are not contiguous;

n³¹And n³²Each independently is 0 or 1.

8. The liquid crystal composition according to item 7, wherein the compound 2 is contained in an amount of 25 to 90% by weight in total and the compound 3 is contained in an amount of 5 to 65% by weight in total, relative to the total weight of the achiral component T.

9. The liquid crystal composition according to any one of items 1 to 8, which contains a chiral agent.

10. The liquid crystal composition according to any one of claims 1 to 9, which comprises one or more compounds selected from the group consisting of an antioxidant and an ultraviolet absorber.

11. A mixture comprising the liquid crystal composition according to any one of items 1 to 10, and a polymerizable monomer.

12. A polymer/liquid crystal composite material which is used in an element driven with a liquid crystal phase exhibiting optical isotropy and which is obtained by polymerizing the mixture according to item 11.

13. The polymer/liquid crystal composite material according to item 12, which is obtained by polymerizing the mixture according to item 11 in a temperature range that exhibits a liquid crystal phase of a non-liquid crystal isotropic phase or an optically isotropic phase.

14. An element comprising the liquid crystal composition according to any one of items 1 to 10, the mixture according to item 11, or the polymer/liquid crystal composite according to item 12 or item 13.

15. The element according to item 14, which can be used for light in the near infrared range (0.72 μm to 2.5 μm).

16. The element according to item 14, which can be used with respect to light in a millimeter wave range (1mm to 10 mm).

17. A lidar comprising at least one element according to item 14.

[ Effect of the invention ]

The preferred liquid crystal composition and polymer/liquid crystal composite material of the present invention contain the compound of formula (1), and thus exhibit stability to heat, light, and the like, and high upper limit temperature and low limit temperature of an optically isotropic liquid crystal phase, and have large dielectric anisotropy and refractive index anisotropy.

The polymer/liquid crystal composite material of the preferred embodiment of the present invention exhibits a high upper limit temperature and a low lower limit temperature of an optically isotropic liquid crystal phase, and an element using the optically isotropic liquid crystal phase can be preferably used for polarization control purposes. In addition, the device using an optically isotropic liquid crystal phase according to a preferred embodiment of the present invention can be used in a wide temperature range and can perform high-speed electro-optical response.

Drawings

FIG. 1 shows an optical system used in the examples [ description of symbols ]

3: light source

4: polarizing element

5: comb type electrode

6: polarization analyzer

7: optical receiver

Detailed Description

In the present specification, the term "liquid crystal compound" refers to a compound having a mesogen (mesogen), and is not limited to a compound having a liquid crystal phase. Specifically, the liquid crystal compound is a generic name of compounds having a liquid crystal phase such as a nematic phase or a smectic phase and compounds having no liquid crystal phase and being usable as a component of the liquid crystal composition.

The term "liquid crystal medium" is a generic term for liquid crystal compositions and polymer/liquid crystal composites.

The "achiral component" is an achiral mesogenic compound, and is a component containing no optically active compound or compound having a polymerizable functional group. Therefore, the "achiral component" does not contain a chiral agent, a polymerizable monomer, a polymerization initiator, a curing agent, or a stabilizer.

The "chiral agent" is an optically active compound, and is an ingredient added to impart a desired twisted molecular arrangement to a liquid crystal composition.

An "element" is an object that abstractly exhibits a desired function, and an element that is related to the property of light is referred to as an optical element or an optical element. Further, depending on the material used, an element using a liquid crystal medium may be referred to as a liquid crystal element.

The "optical element" refers to various elements that function as light modulation, light conversion, or the like by utilizing an electro-optical effect, and examples thereof include: a display element (liquid crystal display element), an optical communication system, an optical modulation element and an optical conversion element used for optical information processing and various sensor systems.

The "optical conversion element" is an element that switches on/off or distributes an optical signal, and switches a path in an optical state without converting the optical signal into an electrical signal.

A change in refractive index caused by applying a voltage to an optically isotropic liquid crystal medium is known as the kerr effect. The kerr effect is a phenomenon in which the electric birefringence value Δ n (E) is proportional to the square of the electric field E, and Δ n (E) ═ K λ E in a material exhibiting the kerr effect²It holds (K: Kerr coefficient (Kerr constant), λ: wavelength). Here, the electrical birefringence value refers to a refractive index anisotropy value induced when an electric field is applied to an isotropic medium.

The term "selective reflection" refers to a case where one of left and right circularly polarized components of light incident in parallel on the helical axis of a chiral nematic liquid crystal or a cholesteric liquid crystal is specifically reflected.

The "liquid crystal compound" and the "liquid crystal composition" are sometimes simply referred to as "compound" and "composition", respectively.

In addition, for example, the upper limit temperature of the liquid crystal phase is a phase transition temperature of a liquid crystal phase-isotropic phase, and may be simply referred to as a clearing point or an upper limit temperature. The lower limit temperature of the liquid crystal phase is sometimes simply referred to as the lower limit temperature. The upper limit temperature of the optically isotropic liquid crystal phase, for example, the blue phase, is the phase transition temperature from the blue phase to the isotropic phase, and the lower limit temperature of the blue phase is the phase transition temperature from the blue phase to the crystal.

The compound represented by formula (1) may be abbreviated as compound 1. The abbreviation may also be applied to the compound represented by the formula (2) or the like. A surrounded by a hexagon in the formulae (2) to (13)⁴¹、A⁵、A⁷¹、A⁸¹、A¹¹¹、A¹³¹The marks are respectively connected with the ring A⁴¹Ring A⁵Ring A⁷¹Ring A⁸¹ring A¹¹¹Ring A¹³¹Etc. correspond to each other. The amount of the compound expressed as a percentage is a weight percentage (wt%) based on the total weight of the composition. Ring A is described in the same formula or different formulas⁵、Z⁵A plurality of the same symbols, but they may be the same or different.

specific examples of "alkyl" in the present specification include-CH₃、-C₂H₅、-C₃H₇、-C₄H₉、-C₅H₁₁、-C₆H₁₃、-C₇H₁₅、-C₈H₁₇、-C₉H₁₉、-C₁₀H₂₁、-C₁₁H₂₃、-C₁₂H₂₅、-C₁₃H₂₇、-C₁₄H₂₉and-C₁₅H₃₁Preferably methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or octyl, and more preferably ethyl, propyl, butyl, pentyl, or heptyl, in order to reduce the viscosity.

specific examples of "alkyl group wherein at least one hydrogen is substituted with halogen" in the present specification include-CH₂F、-CHF₂、-CF₃、-(CH₂)₂-F、-CF₂CH₂F、-CF₂CHF₂、-CH₂CF₃、-CF₂CF₃、-(CH₂)₃-F、-(CF₂)₃-F、-CF₂CHFCF₃、-CHFCF₂CF₃、-(CH₂)₄-F、-(CF₂)₄-F、-(CH₂)₅-F, and- (CF)₂)₅-F。

Specific examples of the "alkoxy group" in the present specification include-OCH₃、-OC₂H₅、-OC₃H₇、-OC₄H₉、-OC₅H₁₁、-OC₆H₁₃and-OC₇H₁₅、-OC₈H₁₇、-OC₉H₁₉、-OC₁₀H₂₁、-OC₁₁H₂₃、-OC₁₂H₂₅、-OC₁₃H₂₇and-OC₁₄H₂₉preferably methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, or heptyloxy, and more preferably methoxy or ethoxy for the purpose of reducing viscosity.

As a specific example of "alkoxy having at least one hydrogen atom substituted with halogen" in the present specification, there may be mentioned-OCH₂F、-OCHF₂、-OCF₃、-O-(CH₂)₂-F、-OCF₂CH₂F、-OCF₂CHF₂、-OCH₂CF₃、-O-(CH₂)₃-F、-O-(CF₂)₃-F、-OCF₂CHFCF₃、-OCHFCF₂CF₃、-O(CH₂)₄-F、-O-(CF₂)₄-F、-O-(CH₂)₅-F, and-O- (CF)₂)₅-F。

Specific examples of "alkenyl" in the present specification include-CH ═ CH₂、-CH＝CHCH₃、-CH₂CH＝CH₂、-CH＝CHC₂H₅、-CH₂CH＝CHCH₃、-(CH₂)₂-CH＝CH₂、-CH＝CHC₃H₇、-CH₂CH＝CHC₂H₅、-(CH₂)₂-CH＝CHCH₃And- (CH)₂)₃-CH＝CH₂Preferably, vinyl, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1-pentenyl, 2-pentenyl, 3-pentenyl, 4-pentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, or 5-hexenyl, and more preferably vinyl, 1-propenyl, 3-butenyl, or 3-pentenyl, for reducing viscosity.

Specific examples of "alkenyl group having at least one hydrogen substituted with halogen" in the present specification include-CH ═ CHF and-CH ═ CF₂、-CF＝CHF、-CH＝CHCH₂F、-CH＝CHCF₃、-(CH₂)₂-CH＝CF₂、-CH₂CH＝CHCF₃、-CH＝CHCF₃and-CH ═ CHCF₂CF₃To reduce the stickiness of the compositionPreferably, it is-CH ═ CF₂And- (CH)₂)₂-CH＝CF₂。

In the present specification, the preferred steric configuration of-CH ═ CH-in the alkenyl group depends on the position of the double bond. Such as-CH ═ CHCH₃、-CH＝CHC₂H₅、-CH＝CHC₃H₇、-CH＝CHC₄H₉、-C₂H₄CH＝CHCH₃and-C₂H₄CH＝CHC₂H₅Among the alkenyl groups having a double bond in the odd-numbered positions in general, the trans configuration is preferred. Such as-CH₂CH＝CHCH₃、-CH₂CH＝CHC₂H₅and-CH₂CH＝CHC₃H₇Among the alkenyl groups having a double bond at the even number position in general, 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. Detailed descriptions are given in mol. crystal.liq. crystal. (1985, 131, 109) and mol. crystal.liq. crystal. (1985, 131, 327).

Specific examples of the "alkoxyalkyl group" in the present specification include-CH₂OCH₃、-CH₂OC₂H₅、-CH₂OC₃H₇、-(CH₂)₂-OCH₃、-(CH₂)₂-OC₂H₅、-(CH₂)₂-OC₃H₇、-(CH₂)₃-OCH₃、-(CH₂)₄-OCH₃And- (CH)₂)₅-OCH₃。

in the present specification, a specific example of "alkenyloxy" is-OCH₂CH＝CH₂、-OCH₂CH＝CHCH₃and-OCH₂CH＝CHC₂H₅。

Specific examples of "alkynyl" in the present specification are-C.ident.CH, -C.ident.CCH₃、-CH₂C≡CH、-C≡CC₂H₅、-CH₂C≡CCH₃、-(CH₂)₂-C≡CH、-C≡CC₃H₇、-CH₂C≡CC₂H₅、-(CH₂)₂-C≡CCH₃and-C ≡ C (CH)₂)₅。

in the present specification, specific examples of "halogen" include fluorine, chlorine, bromine, or iodine.

the liquid crystal composition of the present invention is a composition that contains an achiral component T and a chiral agent and exhibits an optically isotropic liquid crystal phase. The liquid crystal composition of the present invention may contain not only the achiral component T and the chiral agent, but also a solvent, polymerizable monomers (items 5-2-1 and 5-2-2) described later, a polymerization initiator (item 5-2-3), a curing agent (item 5-2-4), a stabilizer (an antioxidant, an ultraviolet absorber, etc.; items 5-2-4), and the like.

1. Achiral component T

The achiral component T contains at least one compound 1. Preferred achiral components T contain at least one compound 2 contained in compound 1 and at least one compound 3 contained in compound 1.

The liquid crystal composition of the present invention is in a form containing the compounds 2 and 3 and other components whose component names are not particularly shown in the specification. A more preferred embodiment is a composition containing compound 2, compound 3, and compounds 4 to 13 described later, and other components whose component names are not particularly shown in the present specification.

The achiral component T of the present invention may include one compound of the compounds 1 to 13, and may include two or more compounds of the compounds 1 to 13. That is, the liquid crystal composition of the present invention may contain, as compound 1, a plurality of compounds 1 represented by formula (1) which are different in structure from each other. This is also the same for compounds 2 to 13.

1-1. liquid crystalline medium

1-1-1. Compound 1

The liquid crystal medium used in the device of the present invention is a liquid crystal medium exhibiting an optically isotropic liquid crystal phase, for example, a blue phase. The liquid-crystalline medium used in the element of the invention comprises at least one or more compounds of formula (1).

In the formula (1), R¹¹Hydrogen or C1-20 alkyl, at least one-CH in the alkyl₂-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;

R¹²is hydrogen, halogen, -C ≡ N, -N ═ C ═ O, -N ═ C ═ S, -CF₃、-OCF₃Or an alkyl group having 1 to 3 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, at least one of the alkyl groups may be substituted by halogen, at least one-CH of the alkyl groups may be substituted by halogen₃May be substituted by-C ≡ N;

Ring A¹¹Ring A¹⁵Each independently represents a 5-to 8-membered ring or a condensed ring having 9 or more carbon atoms, and at least one hydrogen in the ring may be substituted with a halogen, an alkyl group having 1 to 5 carbon atoms, or a halogenated alkyl group. At least one-CH of said alkyl group or said halogenated alkyl group₂-may be substituted by-O-, -S-, or-NH-, at least one-CH in said ring₂-may be substituted by-O-, -S-, or-NH-, at least one-CH ═ in the ring may be substituted by-N ═ in the ring;

Z¹¹～Z¹⁴Each independently represents a single bond or an alkylene group having 1 to 8 carbon atoms, at least one-CH group being contained in the alkylene group₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N ═ N-, -CH ═ N-, -N ═ CH-, -N- (O) -N-, -N ═ N- (O) -, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, at least one hydrogen of said alkylene groups may be substituted by halogen;

n¹¹～n¹³Each independently is 0 or 1.

In the formula (1), R is preferred¹¹Is an alkyl group having 1 to 7 carbon atoms, at least one-CH group in the alkyl group₂-may be substituted by-O-, -CH ═ CH-, or-C ≡ C-, at least one of the hydrogens of the alkyl groups may be substituted by halogen.

preferred ring A¹¹Ring A¹⁴Each ring selected from the group consisting of (A-1) to (A-10) is preferred, and Ring A is preferred¹⁵Is a ring selected from the group consisting of the following (A-1) to (A-3).

Preferred Z¹¹～Z¹⁴Each independently being a single bond, -COO-, or-CF₂O-is formed. More preferably Z¹¹～Z¹⁴At least one of which is-COO-or-CF₂O-。

Preferred n is¹¹～n¹³Total of (n)¹¹+n¹²+n¹³) Is 2 or 3.

Preferred X¹Is halogen, -C ≡ N, -N ≡ C ═ S, -CF₃、-OCF₃Or an alkyl group having 1 to 3 carbon atoms, wherein at least one hydrogen in the alkyl group may be substituted by a halogen.

The liquid crystal medium used in the device of the present invention may contain at least one or more compounds selected from the group consisting of compounds represented by the following formulae (1-2) and (1-3) in an amount of 60% by weight or more, preferably 80% by weight or more, based on the total weight of the achiral component T.

In the formula (1-2), R^1Ais alkyl group having 1 to 12 carbon atoms, alkenyl group having 2 to 12 carbon atoms, or alkoxy group having 1 to 11 carbon atoms, Z^12AAnd Z^13AEach independently being a single bond, -COO-, or-CF₂O-，L^11A、L^12AAnd L^13AEach independently of the other being hydrogen or fluorine, X^1AIs fluorine, chlorine, -CF₃or-OCF₃。

In the formula (1-3), R^1BIs C1-12 alkyl or C1-11 alkoxyalkyl, Z^12BAnd Z^13BEach independently being a single bond, -COO-, or-CF₂O-，L^11B、L^12B、L^13BAnd L^14BEach independently of the other being hydrogen or fluorine, X^1Bis fluorine, chlorine, -CF₃or-OCF₃。

1-1-2. Compound 2

The liquid crystal medium used in the element of the present invention may contain at least one or two or more compounds 2 represented by the following formula (2).

Z¹～Z³Each independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-；

L¹～L⁸Each independently is hydrogen or fluorine;

n¹And n²Each independently is 0 or 1;

X²Is hydrogen, halogen, -SF₅Or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in which alkyl at least one-CH of said alkyl groups₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂-at least one hydrogen of the radicals substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted by fluorine or chlorine, where, in X²in-O-and-CH-and-CO-and-CH-CH-is not contiguous.

When R of formula (2)²When it is hydrogen or methyl, ethyl, with R²The compound having an alkyl group having 3 or more carbon atoms greatly contributes to a reduction in driving voltage. In addition, R²Compounds of methyl group with R²The transparency is higher than that of the hydrogen compound.

When X in the formula (2)²Is fluorine, chlorine, -SF₅、-CF₃、-OCF₃or-CH-CF₃When used, the dielectric anisotropy is large. When X is present²Is fluorine, -CF₃or-OCF₃And is chemically stable. Preferred X²Specific examples thereof are fluorine, chlorine and-CF₃、-CHF₂、-OCF₃and-OCHF₂. More preferred X²Examples of (b) are fluorine, chlorine, -CF₃and-OCF₃. At X²When chlorine or fluorine is used, the melting point is low, and the compatibility with other liquid crystal compounds is particularly excellent. At X²is-CF₃、-CHF₂、-OCF₃and-OCHF₂In the case of (2), particularly large dielectric anisotropy is exhibited.

The compound 2 is preferably a compound represented by any one of the formulae (2-1) to (2-9).

In the formulae (2-1) to (2-9), R^2Aan alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine;

R^2BIs an alkylene group having 1 to 5 carbon atoms, an alkenylene group having 2 to 5 carbon atoms, or an alkynylene group having 2 to 5 carbon atoms.

R of formulae (2-1) to (2-9)^2AIs hydrogen or methyl, ethyl, R^2BThe compound which is a methylene group or an ethylene group having a carbon number of 1 or 2 greatly contributes to a reduction in driving voltage.

In addition, R^2AIs ethyl, R^2BThe methylene group-containing compound is a compound having a high driving voltage reduction effect.

Z^21AAnd Z^22AEach independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-, in the formulae (2-4) and (2-5), Z^21Ais-COO-or-CF₂O-；

L²²、L²⁴～L²⁸Each independently is hydrogen or fluorine;

X^2AIs fluorine, chlorine, -CF₃or-OCF₃。

The compound 2 is preferably a compound represented by the formula (2-1-1), the formula (2-1-2), the formula (2-2-1) to the formula (2-2-5), the formula (2-3-1), the formula (2-3-2), the formula (2-4-1), the formula (2-5-2), the formula (2-9-1) to the formula (2-9-6), and more preferably a compound represented by the formula (2-2-1) to the formula (2-2-5), the formula (2-9-2) to the formula (2-9-5).

R in formula (2-1-1), formula (2-1-2), formula (2-2-1) -formula (2-2-5), formula (2-3-1), formula (2-3-2), formula (2-4-1), formula (2-5-2), formula (2-9-1) -formula (2-9-6)^2AAn alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine;

R^2BAn alkylene group having 1 to 5 carbon atoms, an alkenylene group having 2 to 5 carbon atoms, or an alkynylene group having 2 to 5 carbon atoms,

Z^21Aand Z^22AEach independently of the other being a single bond, -COO-or-CF₂o-and at least one is-COO-or-CF₂o-, in the formulae (2-4-1), (2-5-1) and (2-5-2), Z^21Ais-COO-or-CF₂O-；

L²²、L²⁴、L²⁷、L²⁸Each independently is hydrogen or fluorine;

X^2AIs fluorine, chlorine, -CF₃or-OCF₃。

In the achiral component T of the present invention, the compound 2 includes both a case of containing one compound and a case of containing two or more compounds. When two or more compounds represented by the formulae (2-1) to (2-9) are contained as the compound 2, Z is preferably Z in the compound represented by the formula (2-2-5)^21AIs a single bond, Z^22Ais-CF₂O-、L²²、L²⁴、L²⁷And L²⁸A compound being fluorine and Z^21Ais-CF₂O-、Z^22AIs a single bond, L²²、L²⁷And L²⁸Is fluorine, L²⁴A combination of compounds that are hydrogen.

The total amount of the compound 2 is preferably 25 to 90% by weight, more preferably 35 to 85% by weight, and particularly preferably 45 to 80% by weight, based on the total weight of the achiral component T.

The compound 2 is extremely stable physically and chemically under ordinary use conditions of the device, and has good compatibility with other compounds. The compositions containing the compounds are stable under the conditions of use typical of the elements. Therefore, if the compound 2 is used in a liquid crystal composition, the temperature range of the optically isotropic liquid crystal phase can be expanded, and the compound can be used as an element in a wide temperature range.

In addition, compound 2 has a large dielectric anisotropy and a relatively large refractive index anisotropy, and therefore can be used as a component for reducing the driving voltage of a liquid crystal composition driven in an optically isotropic liquid crystal phase.

1-1-3. Compound 3

The liquid crystal medium used in the element of the present invention may contain at least one or two or more compounds 3 represented by the following formula (3).

In the formula (3), R³Is hydrogen, alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, alkynyl group having 1 carbon atomAlkoxy of up to 19, or alkoxyalkyl of 1 to 20 in total carbon number, at least one-CH of said alkyl groups₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by fluoro or chloro, wherein, at R³wherein-O-and-CH-and-CO-and-CH-are not contiguous;

Z³¹～Z³⁴each independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-；

L³¹～L³⁶Each independently is hydrogen or fluorine;

n³¹and n³²Each independently is 0 or 1.

Compound 3 has four or five benzene rings and has at least one-CF₂An O-linking group. The compound 3 is extremely stable physically and chemically under ordinary use conditions of the element, and has good compatibility with other liquid crystal compounds. The compositions containing the compounds are stable under the conditions of use typical of the elements. Therefore, the temperature range of the nematic phase can be expanded in the composition, and the composition can be used as a display device in a wide temperature range. Further, the compound has large dielectric anisotropy and refractive index anisotropy, and thus can be used as a component for reducing the driving voltage of a composition driven in an optically isotropic liquid crystal phase.

By appropriate selection of R in formula (3)³The group (L) on the benzene ring³¹～L³⁶And X³) Or a bonding group Z³¹A bonding group Z³⁴The physical properties such as the transparent point, the refractive index anisotropy, and the dielectric constant anisotropy can be arbitrarily adjusted.

in the formula (3), Z³¹～Z³⁴Each independently of the other being a single bond, -COO-or-CF₂O-, preferably at least one is-CF₂O-is formed. When Z is³¹～Z³⁴Is a single bond, or-CF₂o-, has a small viscosity, and Z is³¹～Z³⁴is-CF₂O-is a compound having a large dielectric anisotropy. Z in the formula (3)³¹～Z³⁴Is a single bond, -CF₂O-is chemically stable and less likely to deteriorate.

In the formula (3), L³¹～L³⁶each independently hydrogen or fluorine. When L is³¹～L³⁶When the amount of fluorine in (2) is large, the dielectric anisotropy is large. At L³⁵And L³⁶In the case of both fluorine, the dielectric anisotropy is particularly large.

In the formula (3), X³Is hydrogen, halogen, -SF₅Or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in which alkyl at least one-CH of said alkyl groups₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂At least one hydrogen of the radicals substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted by fluorine or chlorine.

In the formula (3), X³Preferably fluorine, chlorine, -CF₃、-CHF₂、-OCF₃and-OCHF₂More preferably fluorine, chlorine, -CF₃and-OCF₃。

When X in the formula (3)³Is fluorine, chlorine, -SF₅、-CF₃、-CHF₂、-CH₂F、-OCF₃、-OCHF₂or-CCH₂F is large in dielectric anisotropy. When X is present³Is fluorine, -OCF₃or-CF₃And is chemically stable.

The compound 3 is preferably a compound represented by any one of the formulae (3-1) to (3-5).

In the formulae (3-1) to (3-5), R^3AAn alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine;

Z^32A～Z^34AEach independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-；

L³¹～L³⁶Each independently is hydrogen or fluorine;

X^3AIs fluorine, chlorine, -CF₃or-OCF₃。

in the achiral component T of the present invention, the compound 3 includes both a case of containing one compound and a case of containing two or more compounds.

When two or more compounds represented by the formula (3) are contained as the compound 3, Z in the compound represented by the formula (3-1) is preferably Z^33Ais-CF₂O-、L³⁵And L³⁶A compound which is fluorine and a compound represented by the formula (3-2) wherein Z is^32Ais-CF₂O-、L³⁵and L³⁶a combination of compounds that are fluorine.

The total amount of the compound 3 is preferably 5 to 65% by weight, more preferably 10 to 60% by weight, and particularly preferably 15 to 55% by weight, based on the total weight of the achiral component T.

The compound 3 is extremely stable physically and chemically under ordinary use conditions of the device, and has good compatibility with other compounds. The compositions containing the compounds are stable under the conditions of use typical of the elements. Therefore, if the compound 3 is used in a liquid crystal composition, the temperature range of the optically isotropic liquid crystal phase can be expanded, and the liquid crystal composition can be used as an element in a wide temperature range.

Further, since compound 3 has relatively large dielectric anisotropy and large refractive index anisotropy, it is useful as a component for lowering the driving voltage of a liquid crystal composition driven in an optically isotropic liquid crystal phase.

1-1-4. Compound 4

The liquid-crystalline medium used in the element of the present invention may further contain at least one or two or more compounds 4 represented by formula (4).

In the formula (4), R⁴Is hydrogen or C1-20 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by fluoro or chloro, wherein, at R⁴wherein-O-and-CH-and-CO-and-CH-are not contiguous;

Ring A⁴¹Ring A⁴⁵Independently of one another, are 1, 4-cyclohexylene, 1, 3-dioxan-2, 5-diyl, 1, 4-phenylene in which one or two hydrogens are replaced by fluorine, 1, 4-phenylene in which two hydrogens are replaced by fluorine and chlorine, pyridine-2, 5-diyl or pyrimidine-2, 5-diyl;

Z⁴¹～Z⁴⁶Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms, at least one-CH group being contained in the alkylene group₂May be-O-, -COO-or-CF₂o-substitution;

L⁴¹～L⁴³Each independently is hydrogen or fluorine;

n⁴¹～n⁴⁵Are each independently 0 or 1, 2. ltoreq. n⁴¹+n⁴²+n⁴³+n⁴⁴+n⁴⁵≤3；

X⁴Is fluorine, chlorine, -CF₃or-OCF₃。

Compound 4 has a chlorophenyl ring. The compound 4 is extremely stable physically and chemically under ordinary use conditions of the element, and has good compatibility with other liquid crystal compounds. And thus a smectic phase is not easily exhibited. The compositions containing the compounds are stable under the conditions of use typical of the elements. Therefore, the temperature range of the nematic phase can be expanded in the composition, and the composition can be used as an element in a wide temperature range. Further, the compound has large dielectric anisotropy and refractive index anisotropy, and thus can be used as a component for reducing the driving voltage of a composition driven in an optically isotropic liquid crystal phase.

By appropriately selecting n in the formula (4)⁴²～n⁴⁵A combination of (2) and R⁴The group on the rightmost benzene ring (L)⁴²、L⁴³And X⁴) Or a bonding group Z⁴²A bonding group Z⁴⁶The physical properties such as the transparent point, the refractive index anisotropy, and the dielectric constant anisotropy can be arbitrarily adjusted.

R in the formula (4)⁴Preferably an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine.

the ring A in the formula (4) is used in terms of stability of the compound or anisotropy of dielectric constant⁴¹Ring A⁴⁵Preference is given to 1, 4-phenylene, 1, 4-phenylene in which one or two hydrogens are replaced by fluorine, respectively. When ring A⁴¹Ring A⁴⁵Substituent of (A), L⁴²and L⁴³When hydrogen is used, the melting point is low, and when fluorine is used as the group, the dielectric anisotropy is large.

Z in the formula (4)⁴¹～Z⁴⁶Each represents a single bond or an alkylene group having 1 to 4 carbon atoms, at least one-CH group being contained in the alkylene group₂May be-O-, -COO-or-CF₂O-substitution. Z in the formula (4)⁴¹～Z⁴⁶Preferably both are single bonds or at least one is-COO-or-CF₂O-in the case where compatibility with other liquid crystal compounds is important, at least one of them is preferably-CF₂O-。

X in the formula (4)⁴Is fluorine, chlorine, -CF₃、-CHF₂、-CH₂F、-OCF₃、-OCHF₂、-OCH₂F、-OCF₂CFHCF₃or-CH ═ CHCF₃Preferably fluorine, chlorine, -CF₃and-OCF₃. When X is present⁴Is fluorine, chlorine, -OCF₃When X is X, compatibility with other liquid crystal compounds at low temperature is excellent⁴is-CF₃The driving voltage reduction effect is large.

In the formula (4), n⁴²+n⁴³+n⁴⁴+n⁴⁵The compound having a high transparency point, n is 2⁴²+n⁴³+n⁴⁴+n⁴⁵The melting point of the compound of 1 is low.

the bonding group Z in the formula (4)⁴¹A bonding group Z⁴⁶Is a single bond, or-CF₂O-is therefore chemically stable and less prone to deterioration. Further, when the bonding group is a single bond, the viscosity is low. In addition, when the bonding group is-CF₂O-is a compound having a large dielectric anisotropy.

Compound 4 has good compatibility with large dielectric anisotropy and large refractive index anisotropy.

The compound 4 is preferably contained in an amount of 0 to 80 wt% in total, more preferably 0 to 50 wt%, and particularly preferably 0 to 20 wt%, based on the total weight of the achiral component T.

1-1-5. Compound 5

The liquid crystal medium or the like used in the element of the present invention may further contain at least one or two or more compounds 5 represented by formula (5).

In the formula (5), R⁵An alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine;

Ring A⁵Independently of one another, are 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1,4-phenylene, 3-fluoro-1, 4-phenylene, 3, 5-difluoro-1, 4-phenylene, 3, 5-dichloro-1, 4-phenylene or pyrimidin-2, 5-diyl;

Z⁵Independently represents a single bond, ethylene, -COO-, -OCO-, -CF₂O-or-OCF₂-；

L⁵¹And L⁵²Each independently is hydrogen or fluorine;

n⁵Is 1,2, 3 or 4, in n⁵in the case of 2,3 or 4, a plurality of rings A are present⁵And Z⁵The same or different.

X⁵Is fluorine, chlorine, -CF₃or-OCF₃。

The compound 5 is extremely stable physically and chemically under ordinary use conditions of the device, and has good compatibility with other liquid crystal compounds. The compositions containing the compounds are stable under the conditions of use typical of the elements. Therefore, the temperature range of the nematic phase can be expanded in the composition, and the composition can be used as an element in a wide temperature range. Further, the compound has large dielectric anisotropy and refractive index anisotropy, and thus can be used as a component for reducing the driving voltage of a composition driven in an optically isotropic liquid crystal phase.

R in the formula (5)⁵Is alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, alkenyl group having 2 to 12 carbon atoms, or alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine. Preferred R in formula (5) is R for improving stability against ultraviolet rays or thermal stability⁵is an alkyl group having 1 to 12 carbon atoms. R in the formula (5) is from the viewpoint of lowering viscosity⁵Preferably C2-12 alkenyl, and preferably C1-12 alkyl for improving stability to ultraviolet light or thermal stability.

R in the formula (5)⁵The alkyl group in (1) does not contain a cyclic alkyl group. Alkoxy groups do not include cyclic alkoxy groups. Alkenyl groups do not comprise cyclic alkenyl groups. The at least one hydrogen fluorine substituted alkenyl group does not comprise at least one hydrogen fluorine substituted cyclic alkenyl group.

Formula (5)) Ring A of (5)⁵Independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 3, 5-difluoro-1, 4-phenylene, 3, 5-dichloro-1, 4-phenylene or pyrimidine-2, 5-diyl, when n is⁵When 2 or more, at least two rings A therein⁵May be the same or different. In order to improve the optical anisotropy, the ring A in the formula (5)⁵1, 4-phenylene or 3-fluoro-1, 4-phenylene, preferably 1, 4-cyclohexylene, in order to reduce the viscosity.

z in the formula (5)⁵Independently a single bond, ethylene, -COO-, -OCO-, -CF₂O-or-OCF₂-, in which n is⁵In the case of 3 or 4, one Z⁵is-CF₂O-is formed. When n is⁵When it is 2 or more, at least two of Z⁵May be the same or different. In order to reduce the viscosity, Z in the formula (5)⁵Preferably a single bond. Z in the formula (5) for improving the dielectric anisotropy and for improving the compatibility⁵preferably-CF₂O-。

L in the formula (5)⁵¹And L⁵²Independently hydrogen or fluorine, L for improving dielectric anisotropy⁵¹and L⁵²Are preferably fluorine, and L is a compound having a high transparency⁵¹And L⁵²Are preferably hydrogen.

X in the formula (5)⁵Is fluorine, chlorine, -CF₃or-OCF₃. In order to improve the dielectric anisotropy, -CF is preferable₃For good compatibility, fluorine, -OCF is preferred₃Chlorine is preferable for improving the refractive index anisotropy.

compound 5 is suitable for the preparation of compositions having large dielectric anisotropy or compatibility at low temperatures. The compound 5 is preferably contained in an amount of 0 to 80% by weight in total, more preferably 0 to 50% by weight, and particularly preferably 0 to 20% by weight, based on the total weight of the achiral component T.

1-1-6. Compound 6

The liquid crystal medium used in the element of the present invention may further contain at least one or two or more compounds 6 represented by formula (6).

In the formula (6), R⁶is hydrogen or C1-20 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by fluoro or chloro, wherein, at R⁶wherein-O-and-CH-and-CO-and-CH-are not contiguous;

L⁶¹～L⁶⁶Each independently is hydrogen or fluorine;

X⁶Is hydrogen, halogen, -SF₅Or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-, or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in which alkyl at least one-CH of said alkyl groups₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂-at least one hydrogen of the radicals substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted by fluorine or chlorine, where, in X⁶In which-O-and-CH-and-CO-and-CH-are not contiguous.

The compound 6 has a dioxane ring and three benzene rings. The compound 6 is extremely stable physically and chemically under ordinary use conditions of the device, and has good compatibility with other liquid crystal compounds despite its high transparency. The composition containing compound 6 is stable under the conditions of use typical of the element. Therefore, the composition containing compound 6 can be used as an element in a wide temperature range by extending the temperature range of the optically isotropic liquid crystal phase. In addition, compound 6 can be used as a component that acts to lower the driving voltage of a composition driven in an optically isotropic liquid crystal phase. If the blue phase is present in the composition comprising the chiral agent and the preferred form of compound 6, it does not react with N^*Phase or eachA homogeneous blue phase coexisting with the same phase. Thus, a composition comprising the preferred form of compound 6 readily exhibits a uniform blue phase.

X in the formula (6)⁶Is hydrogen, halogen, -SF₅Or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-, or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in which alkyl at least one-CH of said alkyl groups₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂-at least one hydrogen of the radicals substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted by fluorine or chlorine, where, in X⁶In which-O-and-CH-and-CO-and-CH-are not contiguous.

As X in formula (6)⁶Specific examples of (3) include fluorine, chlorine and-CF₃、-CHF₂、-OCF₃and-OCHF₂Preferably fluorine, chlorine, -CF₃and-OCF₃. X in the formula (6)⁶When chlorine or fluorine is used, the melting point is relatively low, and the compatibility with other liquid crystal compounds is particularly excellent. X in the formula (6)⁶is-CF₃、-CHF₂、-OCF₃and-OCHF₂In the case of (2), the dielectric anisotropy is relatively large. When X in the formula (6)⁶Is fluorine, chlorine, -SF₅、-CF₃、-OCF₃or-CH-CF₃When X is used, the dielectric anisotropy is large⁶Is fluorine, -CF₃or-OCF₃It is chemically stable.

Compound 6 is suitable for the preparation of compositions having large dielectric anisotropy. Compound 6 has the effect of easily showing a blue phase and improving the clearing point.

in order to increase the clearing point, it is preferable to contain about 1.0% by weight or more of compound 6 in total relative to the total weight of the achiral component T. In order to lower the lower limit temperature of the liquid crystal phase, the total amount of the compound 6 is preferably 0 to 80% by weight, more preferably 0 to 50% by weight, and particularly preferably 0 to 20% by weight, based on the total weight of the achiral component T.

1-1-7. Compound 7

The liquid-crystalline medium used in the element of the present invention may further contain at least one or two or more compounds 7 represented by formula (7).

In the formula (7), R⁷¹And R⁷²Independently represents an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine;

Ring A⁷¹And ring A⁷²Each independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 3-fluoro-1, 4-phenylene or 2, 5-difluoro-1, 4-phenylene;

Z⁷Each independently is a single bond, ethylene, -COO-, or-OCO-;

n⁷Is 1,2 or 3, in n⁷In the case of 2 or 3, a plurality of rings A are present⁷¹And Z⁷The same or different.

The absolute value of the dielectric anisotropy value of compound 7 was small and was a nearly neutral compound. In the formula (7), n⁷the compound having 1 has mainly an effect of adjusting viscosity or refractive index anisotropy value, and in the formula (7), n⁷The compound of 2 or 3 has an effect of increasing the temperature range of the optically isotropic liquid crystal phase such as the clearing point, or an effect of adjusting the refractive index anisotropy value.

R in the formula (7)⁷¹And R⁷²Each independently is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, an alkenyl group having 2 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms in which at least one hydrogen is substituted with fluorine. In order to reduce the viscosity, R in formula (7) of Compound 7⁷¹And R⁷²Preferably an alkenyl group having 2 to 12 carbon atoms. To improve stability against ultraviolet rays, or to improve stability against heatR in the formula (7)⁷¹And R⁷²preferably an alkyl group having 1 to 12 carbon atoms.

Ring A in formula (7)⁷¹And ring A⁷²Independently is 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 3-fluoro-1, 4-phenylene or 2, 5-difluoro-1, 4-phenylene, when n is⁷when 2 or more, at least two rings A therein⁷¹May be the same or different. To increase the optical anisotropy of Compound 7, Ring A⁷¹And ring A⁷²1, 4-phenylene or 3-fluoro-1, 4-phenylene is preferred. To reduce the viscosity of Compound 7, Ring A⁷¹And ring A⁷²is a1, 4-cyclohexylene group.

Z in the formula (7)⁷Each independently is a single bond, ethylene, or-COO-, -OCO-, when n is⁷When it is 2 or more, at least two of Z⁷May be the same or different. For reducing the viscosity, preferred is Z⁷is a single bond.

Since the driving voltage of the liquid crystal composition becomes high and the viscosity becomes low if the content of the compound represented by formula (7) is increased, it is desirable that the content is small from the viewpoint of the driving voltage as long as the required value of the viscosity of the liquid crystal composition is satisfied. The compound 7 is preferably contained in an amount of 0 to 80% by weight in total, more preferably 0 to 50% by weight, and particularly preferably 0 to 20% by weight, based on the total weight of the achiral component T.

1-1-8, Compound 8

The liquid-crystalline medium used in the element of the present invention may further contain at least one or two or more compounds 8 represented by formula (8).

In the formula (8), R⁸Is an alkyl group having 1 to 10 carbon atoms, at least one-CH group in the alkyl group₂-may be substituted by-O-, at least one of said alkyl groups- (CH)₂)₂-may be substituted by-CH ═ CH-;

Ring A⁸¹Ring A⁸⁶Each independently is 1, 4-cyclohexylene or 1,4-phenylene, at least one-CH of said 1, 4-cyclohexylene₂-at least one- (CH) of said 1, 4-cyclohexylene group, which may be substituted by-O-)₂)₂-may be substituted with-CH ═ CH-, at least one-CH ═ of the 1, 4-phenylene may be substituted with-N ═ and at least one hydrogen of the 1, 4-phenylene may be substituted with halogen;

Z⁸¹～Z⁸⁷Are each independently a single bond, - (CH)₂)₂-、-COO-、-OCO-、-CF₂O-、-OCF₂-, or-CH ═ CH-;

L⁸¹And L⁸²each independently is hydrogen or fluorine;

n⁸¹～n⁸⁷Each independently is 0 or 1; n is⁸¹～n⁸⁷The sum of (a) is 1,2, 3, or 4;

X⁸Is fluorine, -CF₃or-OCF₃。

1-1-9. Compound 9

The liquid-crystalline medium used in the element of the present invention may further contain at least one or two or more compounds 9 represented by formula (9).

In the formula (9), R⁹Is hydrogen, alkyl group having 1 to 20 carbon atoms, alkenyl group having 2 to 20 carbon atoms, alkynyl group having 2 to 20 carbon atoms, alkoxy group having 1 to 19 carbon atoms or alkoxyalkyl group having 1 to 20 carbon atoms in total, at least one-CH in the alkyl groups₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by fluoro or chloro, wherein, at R⁹wherein-O-and-CH-and-CO-and-CH-are not contiguous;

Z⁹¹～Z⁹³Each independently of the other being a single bond, -COO-or-CF₂O-and at least one is-COO-or-CF₂O-；

L⁹¹～L⁹⁸Each independently is hydrogen or fluorine;

n⁹¹And n⁹²each independently is 0 or 1;

X⁹Is hydrogen, halogen, -SF₅Or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in which alkyl at least one-CH of said alkyl groups₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂-at least one hydrogen of the radicals substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted by fluorine or chlorine, where, in X⁹¹In which-O-and-CH-and-CO-and-CH-are not contiguous.

1-1-10. Compound 10

The liquid crystal medium used in the element of the present invention may further contain at least one or two or more compounds 10 represented by formula (10).

In the formula (10), R¹⁰Is hydrogen or C1-20 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, any of-CH in the alkyl groups and in the alkyl groups₂-at least one hydrogen of the groups substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-may be substituted by halogen or alkyl having 1 to 3 carbon atoms;

Y¹⁰¹And Y¹⁰²Are each independently-O-or-CH₂-；

Z¹⁰¹is-CF₂O-or-COO-, Z¹⁰²Is a single bond or-CH₂CH₂-, and a CH₂May be substituted by oxygen atoms, Z¹⁰³Is a single bond, -CH₂CH₂-、-CF₂O-or-COO-;

L¹⁰¹～L¹⁰⁶Each independently is hydrogen or fluorine;

X¹⁰Is hydrogen, halogen, -SF₅Or an alkyl group having 1 to 10 carbon atoms, at least one-CH group being present in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, at least one hydrogen of said alkyl groups may be substituted by fluoro or chloro, wherein, at X, X is¹⁰In which-O-and-CH-and-CO-and-CH-are not contiguous.

1-1-11. Compound 11

The liquid-crystalline medium used in the element of the present invention may further contain at least one or two or more compounds 11 represented by formula (11).

In the formula (11), R¹¹Alkyl group having 1 to 12 carbon atoms, alkenyl group having 2 to 12 carbon atoms, alkoxy group having 1 to 11 carbon atoms;

Ring A¹¹¹And ring A¹¹²Each independently represented by the following formula;

Z¹¹¹～Z¹¹³Are each independently a single bond, - (CH)₂)₂-、-COO-、-CF₂O-, or-CH ═ CH-;

L¹¹¹～L¹¹⁴Each independently is hydrogen or halogen;

n¹¹¹is 0, 1 or 2, at n¹¹¹In the case of 2, there are a plurality of Z' s¹¹¹And ring A¹¹¹The same or different.

X¹¹Is hydrogen, halogen, -CF₃、-OCF₃、-C≡N。

1-1-12. Compound 12

The liquid crystal medium used in the element of the present invention may further contain at least one or two or more compounds 12 represented by formula (12).

In the formula (12), R¹²Is branched alkyl or branched alkenyl with 3-20 carbon atoms, and at least one-CH in the branched alkyl or branched alkenyl₂-at least one-CH of said branched alkyl or branched alkenyl, which may be substituted by-O-)₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, at least one hydrogen of said branched alkyl or branched alkenyl group may be substituted by fluorine;

Ring A¹²¹Ring A¹²⁵Each independently is 1, 4-phenylene, 1, 3-dioxan-2, 5-diyl, tetrahydropyran-3, 6-diyl, pyrimidine-2, 5-diyl, pyridine-2, 5-diyl, or naphthalene-2, 6-diyl, at least one hydrogen in the ring being substituted with fluorine or chlorine;

Z¹²¹～Z¹²⁴Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms, at least one-CH group being contained in the alkylene group₂May be substituted by-O-, -COO-, -OCO-, or-CF₂O-substituted, at least one of said alkylene-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, at least one hydrogen of said alkylene groups may be substituted by halogen;

n¹²¹～n¹²³Are each independently 0 or 1, 1. ltoreq. n¹²¹+n¹²²+n¹²³≤3；

X¹²Is fluorine, chlorine, -SF₅C.ident.N, -N.C.S, or C1-3 alkyl in which at least one hydrogen is substituted by halogen, at least one-CH in the alkyl₂-may be substituted by-O-, at least one-CH of said alkyl groups₂-CH₂-may be substituted by-CH ═ CH-, or-C ≡ C-.

1-1-13. Compound 13

The liquid crystal medium used in the element of the present invention may further contain at least one or two or more compounds 13 represented by formula (13).

In the formula (13), R¹³Is hydrogen or C1-20 alkyl, at least one-CH in the alkyl₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-, among the alkyl groups and-CH among the alkyl groups₂-at least one hydrogen of the groups substituted by-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-may be substituted by halogen or alkyl having 1 to 3 carbon atoms;

Ring A¹³¹ring A¹³⁴Each independently represents a benzene ring, a naphthalene ring, a thiophene ring, a piperidine ring, a cyclohexene ring, a bicyclooctane ring, a tetrahydronaphthalene ring or a cyclohexane ring, at least one hydrogen in the rings may be substituted by a halogen, an alkyl group having 1 to 3 carbon atoms or a halogenated alkyl group having 1 to 3 carbon atoms, and at least one or two-CH groups in the rings₂-may be substituted by-O-or-S-but the oxygen atoms are not adjacent, -CH ═ may be substituted by-N ═ c;

W is CH or N;

Z¹³¹～Z¹³⁵Each independently represents a single bond or an alkylene group having 1 to 4 carbon atoms, at least one-CH group being contained in the alkylene group₂May be-O-, -COO-or-CF₂O-substitution;

L¹³¹～L¹³⁴Each independently is hydrogen or halogen;

n¹³¹～n¹³⁴Are each independently 0 or 1, 0 ≦ n¹³¹+n¹³²+n¹³³+n¹³⁴≤2；

X¹³Is hydrogen, halogen, -SF₅-C ≡ N, -N ≡ C ═ S or an alkyl group having 1 to 10 carbon atoms, and at least one-CH group in the alkyl group₂-may be substituted by-O-, -S-, -COO-or-OCO-, the alkyl group and the-CH in the alkyl group₂-at least one-CH-substituted group selected from-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-and-C ≡ C-substituted groups₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-, in the alkyl group, -CH in the alkyl group₂-at least one-CH in said alkyl and in groups substituted with-O-, -S-, -COO-, -OCO-, -CH ═ CH-, -CF ═ CF-, or-C ≡ C-)₂-CH₂-substituted by-CH ═ CH-, -CF ═ CF-or-C ≡ C-At least one hydrogen of the radicals being substituted by fluorine or chlorine, wherein, in X¹³in-O-and-CH-are not contiguous, -CO-and-CH-are not contiguous.

1-1-14 Properties of Compounds 8 to 13

the compounds 8 to 13 are extremely stable physically and chemically under ordinary use conditions, and have relatively good compatibility with other liquid crystal compounds although they have a high transparency. The composition containing the compounds 8 to 13 is relatively stable under the usual use conditions of the device. Therefore, in the compositions containing compounds 8 to 13, the temperature range of the optically isotropic liquid crystal phase can be expanded, and the composition can be used as an element in a wide temperature range. Further, the compounds 8 to 13 can be used as components which act to lower the driving voltage of a composition driven in an optically isotropic liquid crystal phase. In addition, in the composition comprising the compounds 8 to 13 and the chiral agent, if a blue phase is expressed, the blue phase does not react with N^*A homogeneous blue phase in which phases or isotropic phases coexist. That is, the compounds 8 to 13 are compounds which easily exhibit a uniform blue phase. In addition, a very large dielectric anisotropy is exhibited.

X in formulae (8) to (13)⁸、X⁹、X¹⁰、X¹¹、X¹²、X¹³Are each preferably fluorine, chlorine, -CF₃、-CHF₂、-OCF₃and-OCHF₂More preferably fluorine, chlorine, -CF₃and-OCF₃。

X in formulae (8) to (13)⁸、X⁹、X¹⁰、X¹¹、X¹²、X¹³When chlorine or fluorine is used, the compounds (8) to (13) have relatively low melting points and are particularly excellent in compatibility with other liquid crystal compounds. X in the formulae (8) to (13)⁸、X⁹、X¹⁰、X¹¹、X¹²、X¹³is-CF₃、-SF₅、-CHF₂、-OCF₃and-OCHF₂In the case of (2), compounds 8 to 13 exhibited relatively large dielectric anisotropy.

When X is present⁸、X⁹、X¹⁰、X¹¹、X¹²、X¹³Is fluorine, -CF₃or-OCF₃And is chemically stable.

Compounds 8 to 13 are suitable for the preparation of compositions having large dielectric anisotropy, so that the driving voltage in the element of the present invention can be lowered. The content of one or more compounds 8 to 13 is preferably 0 to 80% by weight in total, more preferably 0 to 50% by weight, and particularly preferably 0 to 20% by weight, based on the total weight of the achiral component T.

1-1-15 Synthesis of Compounds 1 to 13

Compound 1 and compounds 2 to 13 can be synthesized by appropriately combining the methods in organic synthetic chemistry. Methods for introducing a target terminal group, ring, and bonding group into a starting material are described in Organic Synthesis (Organic Synthesis), John Wiley & Sons, Inc, Organic Reactions (Organic Reactions), John Wiley & Sons, Inc, Integrated Organic chemistry, Pergamon Press, New laboratory chemistry lecture (pill), and the like.

For example, compound 1 and compounds 2 to 13 can be synthesized by the method disclosed in Japanese patent No. 2959526.

2. Chiral agents

the chiral agent contained in the optically isotropic liquid crystal composition is an optically active compound, and preferably contains a compound selected from compounds having no radical polymerizable group.

The chiral agent used in the composition of the present invention is preferably a compound having a large Twisting Power (Helical Twisting Power). The compound having a large twisting force is advantageous in practical use because the amount of addition required to obtain a desired pitch can be reduced, and thus an increase in driving voltage can be suppressed. Specifically, compounds represented by the formulae (K1) to (K7) are preferable. Among the above compounds, the chiral agents to be added to the liquid crystal composition are preferably represented by formulae (K2-1) to (K2-8) contained in formula (K2), formulae (K4-1) to (K4-6) contained in formula (K4), formulae (K5-1) to (K5-3) and formula (K6) contained in formula (K5), and more preferably represented by formulae (K4-1) to (K4-6), formulae (K5-1) to (K5-3) and formula (K6). In the compounds (K4) to (K7), binaphthyl and octahydronaphthyl are optically active sites, and the chiral agent is not limited.

In the formulae (K1) to (K7), R^KIndependently hydrogen, halogen, -C ≡ N, -N ═ C ═ O, -N ═ C ═ S or alkyl with carbon number of 1-12, and the R is^KAt least one-CH of₂-may be substituted by-O-, -S-, -COO-or-OCO-, said R^Kat least one-CH of₂-CH₂-may be substituted by-CH-, -CF-or-C ≡ C-, said R ≡ C ≡ s^KAt least one hydrogen in (a) may be substituted by fluorine or chlorine;

A^KEach independently an aromatic 6-to 8-membered ring, a non-aromatic 3-to 8-membered ring, or a condensed ring having at least 9 carbon atoms, wherein at least one hydrogen in the ring may be substituted with a halogen, an alkyl group having 1 to 3 carbon atoms or a halogenated alkyl group, and at least one-CH in the ring₂-may be substituted by-O-, -S-or-NH-, at least one-CH-in said ring may be substituted by-N ═ c;

Y^KIndependently hydrogen, halogen, alkyl group having 1 to 3 carbon atoms, halogenated alkyl group having 1 to 3 carbon atoms, aromatic 6 to 8-membered ring, non-aromatic 3 to 8-membered ring, or condensed ring having 9 or more carbon atoms, wherein at least one hydrogen in the ring may be substituted by halogen, alkyl group having 1 to 3 carbon atoms or halogenated alkyl group, and at least one-CH in the alkyl group₂-may be substituted by-O-, -S-or-NH-, at least one-CH ═ of said alkyl groups may be substituted by-N ═ of said alkyl groups;

Z^KIndependently a single bond, alkylene group having 1 to 8 carbon atoms, and Z^KAt least one-CH of₂-may be substituted by-O-, -S-, -COO-, -OCO-, -CSO-, -OCS-, -N ═ N-, -CH ═ N-or-N ═ CH-, said Z^KAt least one-CH of₂-CH₂-canSubstituted by-CH-, -CF-or-C ≡ C-, said Z ≡ C ≡^KAt least one hydrogen in (a) may be substituted with a halogen;

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

mK is independently an integer of 1 to 3.

R in the formulae (K2-1) to (K2-8), the formulae (K4-1) to (K4-6) and the formulae (K5-1) to (K5-3)^KIndependently an alkyl group having 3 to 10 carbon atoms or an alkoxy group having 3 to 10 carbon atoms, at least one-CH in the alkyl group or the alkoxy group₂-CH₂-may be substituted by-CH ═ CH-.

Depending on the desired properties of the liquid crystal composition, chiral agents having relatively low twisting power may be used. The chiral agent having relatively low twisting power is required to have high solubility in the liquid crystal composition, and examples thereof include compounds represented by the following formulae (Op-1) to (Op-13).

As the chiral agent contained in the liquid crystal composition, one compound may be used, or two or more compounds may be used.

In order to easily exhibit an optically isotropic liquid crystal phase, the chiral agent is preferably contained in an amount of 0.5 to 40 wt%, more preferably 1 to 25 wt%, and particularly preferably 2 to 15 wt%, based on the total weight of the liquid crystal composition of the present invention.

In order to set a desired pitch length, a chiral agent having a polymerizable group or a chiral agent which undergoes photoisomerization may be used.

3. Optically isotropic liquid crystalline phase

The 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. The "pitch based on the liquid crystal order of the liquid crystal composition on a microscopic scale (hereinafter, sometimes referred to as pitch)" is preferably 700nm or less, more preferably 500nm or less, and most preferably 350nm or less.

Here, the "non-liquid crystal isotropic phase" is a generally defined isotropic phase, that is, a disordered phase, and is an isotropic phase in which even if a region having a local order parameter that is not zero is formed, the formation cause of the region is a shake. For example, an isotropic phase that is expressed on the high temperature side of the nematic phase corresponds to a non-liquid crystal isotropic phase in the present specification. The same definition is applied to the chiral liquid crystal in the present specification.

In the present specification, the "optically isotropic liquid crystal phase" refers to a phase that exhibits optically isotropic liquid crystal phase rather than shaking, and for example, a phase that exhibits platelet (platelet) structure (blue phase in a narrow sense) is an example thereof.

In the optically isotropic liquid crystal composition of the present invention, although the liquid crystal phase is optically isotropic, a typical platelet structure may not be observed in a blue phase under observation with a polarizing microscope. Therefore, in the present specification, a phase exhibiting a platelet structure is referred to as a blue phase, and an optically isotropic liquid crystal phase including the blue phase is referred to as an optically isotropic liquid crystal phase. That is, the blue phase is contained in the optically isotropic liquid crystal phase.

In general, blue phases are classified into three kinds of blue phases I, II, and III, all of which are optically active and isotropic. In the blue phase of the blue phase I or the blue phase II, two or more diffracted lights due to Bragg reflection (Bragg reflection) from different lattice planes are observed. The blue phase is generally observed in the temperature region between the non-liquid crystal isotropic phase and the chiral nematic phase.

The state where the optically isotropic liquid crystal phase does not exhibit two or more colors of diffracted light means that platelet structures observed in the blue phases I and II are not observed, and the state is substantially monochromatic on one side. In the optically isotropic liquid crystal phase that does not exhibit two or more colors of diffracted light, it is not necessary that the color brightness be uniform in the plane.

The optically isotropic liquid crystal phase that does not exhibit two or more colors of diffracted light has an advantage that the intensity of reflected light due to bragg reflection is suppressed or shifted to the low wavelength side.

In addition, although color sensitivity may sometimes be a problem when used as a display element in a liquid crystal medium that reflects visible light, reflection of visible light can be eliminated at a pitch longer than a narrow blue phase (a phase that exhibits a platelet structure) because the reflection wavelength shifts at a low wavelength in a liquid crystal that does not exhibit diffracted light of two or more colors.

The optically isotropic liquid crystal composition of the present invention can also be obtained by adding a chiral agent to a composition having a chiral nematic phase and not having an optically isotropic liquid crystal phase. Further, the composition of a liquid crystal having a chiral nematic phase and no optical isotropy contains the compound 1, an optically active compound, and optionally other components. In this case, since an optically isotropic liquid crystal phase is not exhibited, it is preferable to add a chiral agent at a concentration such that the pitch becomes 700nm or more.

The temperature range in which the liquid crystal composition of the preferred embodiment of the present invention exhibits an optically isotropic liquid crystal phase can be expanded as follows: a chiral agent is added to a liquid crystal composition having a wide temperature range in which a nematic phase or a chiral nematic phase and an isotropic phase coexist, thereby expressing an optically isotropic liquid crystal phase. For example, a liquid crystal composition having a wide temperature range in which a nematic phase and an isotropic phase coexist is prepared by mixing a liquid crystal compound having a high clearing point with a liquid crystal compound having a low clearing point, and a chiral agent is added thereto, whereby a composition exhibiting an optically isotropic liquid crystal phase in a wide temperature range can be prepared.

as the liquid crystal composition having a wide temperature range in which a nematic phase or a chiral nematic phase and an isotropic phase coexist, a liquid crystal composition having a difference between the upper limit temperature and the lower limit temperature in which a chiral nematic phase and a non-liquid crystal isotropic phase coexist, which is 3 to 150 ℃, is preferable, and a liquid crystal composition having a difference between 5 and 150 ℃ is more preferable. Further, the difference between the upper limit temperature and the lower limit temperature at which the nematic phase and the non-liquid crystal isotropic phase coexist is preferably 3 to 150 ℃.

when an electric field is applied to the liquid crystal medium of the present invention in an optically isotropic liquid crystal phase, electric birefringence occurs, but the kerr effect is not necessarily the case.

Since the longer the pitch, the larger the electric birefringence in the optically isotropic liquid crystal phase, the longer the pitch can be set by adjusting the kind and content of the chiral agent so as to increase the electric birefringence as long as the requirements for other optical characteristics (transmittance, diffraction wavelength, and the like) are satisfied.

4. Other ingredients

The optically isotropic liquid crystal composition of the present invention may further contain a solvent, a polymer substance, a dichroic dye, a photochromic compound, and the like, within a range that does not largely affect the properties of the composition.

Examples of the dichroic dye used in the liquid crystal composition of the present invention include merocyanine type, styryl type, azo type, methylamine type, azoxy type, quinophthalone type, anthraquinone type, tetrazine type, and the like.

5. Optically isotropic polymer/liquid crystal composite

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

5-1. Polymer/liquid crystal composite

The polymer/liquid crystal composite material of the present invention is a composite material including a liquid crystal composition and a polymer, exhibits optical isotropy, and is useful for a light conversion element driven by an optically isotropic liquid crystal phase. The liquid crystal composition contained in the polymer/liquid crystal composite material of the present invention is the liquid crystal composition of the present invention.

In the present specification, 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 compound of a polymer, and the polymer and the liquid crystal composition may be in a phase-separated state in a state where a part or all of the polymer is not dissolved in the liquid crystal composition. In the present specification, a nematic phase refers to a narrow nematic phase that does not include a chiral nematic phase, unless otherwise specified.

The optically isotropic polymer/liquid crystal composite material according to the preferred embodiment of the present invention can exhibit an optically isotropic liquid crystal phase in a wide temperature range. In addition, the polymer/liquid crystal composite material according to the preferred embodiment of the present invention has an extremely high response speed. In addition, the polymer/liquid crystal composite material according to the preferred embodiment of the present invention can be preferably used for a light conversion element based on the above-described effects.

5-2. polymerizable monomer and the like

In the present specification, a mixture containing a polymerizable monomer and a liquid crystal composition is referred to as a "polymerizable monomer/liquid crystal mixture". The "polymerizable monomer/liquid crystal mixture" may contain, as required, a polymerization initiator (item 5-2 to 3), a curing agent (item 5-2 to 4), a curing accelerator (item 5-2 to 4), a stabilizer (item 5-2 to 4), a dichroic dye, a photochromic compound, and the like, which will be described later, in such a range that the effects of the present invention are not impaired. For example, the polymerizable monomer/liquid crystal mixture of the present invention may contain 0.1 to 20 parts by weight of a polymerization initiator per 100 parts by weight of the polymerizable monomer, if necessary. The "polymerizable monomer/liquid crystal mixture" is necessarily a liquid crystal medium when polymerized at a temperature at which a blue phase is exhibited, but is not necessarily a liquid crystal medium when polymerized at a temperature at which an isotropic phase is formed.

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 a mixture of a polymerizable monomer or the like and the liquid crystal composition exhibits an isotropic phase or a blue phase and at a temperature at which the mixture becomes an isotropic phase or an optically isotropic liquid crystal phase. That is, it is preferable that the polymer/liquid crystal composite material is at a temperature at which light on the longer wavelength side than visible light is not substantially scattered and the polymer/liquid crystal composite material exhibits optical isotropy after polymerization.

As the raw material of the polymer constituting the composite material of the present invention, for example, a low molecular weight monomer, a macromonomer, or an oligomer can be used, and in the present specification, the raw material monomer of the polymer is used in the meaning including the low molecular weight monomer, the macromonomer, or the oligomer. Further, since the obtained polymer preferably has a three-dimensional crosslinked structure, a polyfunctional monomer having two or more polymerizable functional groups is preferably used as a raw material monomer 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 raw material monomers for the polymer, it is preferable to add 10% by weight or more of a monomer containing two or more polymerizable functional groups to the monomer because the composite material of the present invention is likely to exhibit high transparency and isotropy.

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

In order to obtain a more preferable composite material, a monofunctional or polyfunctional monomer having a mesogen portion and a monomer having a polymerizable functional group which does not have a mesogen portion may be used in combination. Further, if necessary, a polymerizable compound other than a monofunctional or polyfunctional monomer having a mesogen portion and a monomer having a polymerizable functional group without a mesogen portion may be used.

5-2-1. monofunctional or polyfunctional monomer having mesogen portion

The monofunctional or difunctional monomer having a mesogen portion is not particularly limited in structure, and examples thereof include compounds represented by the following formula (M1) or formula (M2).

R^a-Y-(A^M-Z^M)_m1-A^M-Y-R^b(M1)

R^b-Y-(A^M-Z^M)_m1-A^M-Y-R^b(M2)

in the formula (M1), R^aIs hydrogen, halogen, -C ≡ N, -N ═ C ═ O, -N ═ C ═ S, or alkyl having 1 to 20 carbon atoms, and at least one-CH in the alkyl group₂-may be substituted by-O-, -S-, -CO-, -COO-, or-OCO-, at least one of said alkyl groups being-CH₂-CH₂-may be substituted by-CH ═ CH-, -CF ═ CF-, or-C ≡ C-, in the alkyl group, at least one-CH in the alkyl group₂-in a-O-, -S-, -COO-, or-OCO-substituted radical, or at least one-CH in said alkyl radical₂-CH₂-at least one hydrogen of the groups substituted with-CH ═ CH-, -CF ═ CF-or-C ≡ C-may be substituted with halogen or-C ≡ N. R^bIndependently a polymerizable group of formula (M3-1) to formula (M3-7).

Preferred R^aIs hydrogen, halogen, -C ≡ N, -CF₃、-CF₂H、-CFH₂、-OCF₃、-OCF₂H. An alkyl group having 1 to 20 carbon atoms, an alkoxy group having 1 to 19 carbon atoms, an alkenyl group having 2 to 21 carbon atoms, and an alkynyl group having 2 to 21 carbon atoms. Especially preferred R^ais-C.ident.N, an alkyl group having 1 to 20 carbon atoms, and an alkoxy group having 1 to 19 carbon atoms.

In the formula (M2), R^bIndependently a polymerizable group of formula (M3-1) to formula (M3-7).

Here, in the formulae (M3-1) to (M3-7), R^dIndependently hydrogen, halogen or alkyl with 1-5 carbon atoms, wherein at least one hydrogen in the alkyl can be substituted by halogen. Preferred R^dHydrogen, halogen and methyl. Particularly preferredR^dHydrogen, fluorine and methyl.

Further, it is preferable that the formula (M3-2), the formula (M3-3), the formula (M3-4) and the formula (M3-7) are polymerized by radical polymerization. The polymerization of the formula (M3-1), the formula (M3-5) and the formula (M3-6) is preferably carried out by cationic polymerization. Since the polymerization is all living polymerization, 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.

In the formulae (M1) and (M2), A^MIndependently an aromatic or non-aromatic 5-membered ring, 6-membered ring or condensed ring having 9 or more carbon atoms, and at least one-CH in the ring₂may be substituted by-O-, -S-, -NH-, or-NCH₃-substituted, at least one-CH ═ in the ring may be substituted with-N ═ and at least one hydrogen atom in the ring may be substituted with halogen, and alkyl group having 1 to 5 carbon atoms, or halogenated alkyl group. Preferred A^MThe concrete example is as follows: 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, naphthalene-2, 6-diyl, tetrahydronaphthalene-2, 6-diyl, fluorene-2, 7-diyl, or bicyclo [2.2.2 ] diyl]Octane-1, 4-diyl, at least one-CH in the ring₂-may be substituted with-O-, at least one-CH ═ in the ring may be substituted with-N ═ and at least one hydrogen in the ring may be substituted with halogen, alkyl group having 1 to 5 carbon atoms or halogenated alkyl group having 1 to 5 carbon atoms.

Considering the stability of the compound, compared to-CH where oxygen is adjacent to oxygen₂-O-O-CH₂-CH in which oxygen is not adjacent to oxygen₂-O-CH₂-O-is more preferred. The same applies to sulfur.

Of the specific examples, A is particularly preferred^MIs 1, 4-cyclohexylene, 1, 4-cyclohexenylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 3-difluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene, 2, 6-difluoro-1, 4-phenylene, 2-methyl-1, 4-phenylene, 2-trifluoromethyl-1, 4-phenylene, 2, 3-bis (trifluoromethyl) -1, 4-phenylene, naphthalene-2, 6-diyl, tetrahydronaphthalene-2, 6-diyl, fluorene-2, 7-diyl, 9-methylfluorene-2, 7-diyl, 1, 3-dioxane-2, 5-diyl, Pyridine-2, 5-diyl, and pyrimidine-2, 5-diyl. Furthermore, what is needed isThe three-dimensional configurations of the 1, 4-cyclohexylene group and the 1, 3-dioxane-2, 5-diyl group are in the trans-configuration rather than in the cis-configuration.

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.

In the formulas (M1) and (M2), Y is independently a single bond or an alkylene group having 1 to 20 carbon atoms, and at least one-CH in the alkylene group₂-may be substituted by-O-, -S-, at least one-CH of said alkylene groups₂-CH₂-may be substituted by-CH ═ CH-, -C ≡ C-, -COO-, or-OCO-. Preferred Y is a single bond, - (CH)₂)_m2-、-O(CH₂)_m2-, and- (CH)₂)_m2O- (in the formula, m2 is an integer of 1-20). Particularly preferred Y is a single bond, - (CH)₂)_m2-、-O(CH₂)_m2-, and- (CH)₂)_m2o- (in the formula, m2 is an integer of 1-10). In view of stability of the compound, -Y-R^aand-Y-R^bIt is preferred that none of the groups-O-, -O-S-, -S-O-, or-S-.

In the formulae (M1) and (M2), Z^MIndependently 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 formulae (M1) and (M2), M1 is an integer of 1 to 6. Preferably, m1 is an integer of 1 to 3. When m1 is 1, the bicyclic compound has two 6-membered rings or the like. When m1 is 2 or 3, the compounds are tricyclic and tetracyclic, respectively. For example, when m1 is 1, two A' s^MMay be the same or may be different. In addition, for example, when m1 is 2, three A^M(or two Z^M) May be the same or may be different. The same applies to m1 being 3-6. With respect to R^a、R^b、R^d、Z^M、A^MAnd Y are also the same.

The compound represented by the formula (M1) (M1) and the compound represented by the formula (M2) (M2) contain a larger amount of the compound than the naturally occurring amount²H (deuterium),¹³C-like isotopes have the same properties and are therefore preferably used.

More preferable examples of the compound (M1) and the compound (M2) are the compounds (M1-1) to (M1-41) and the compounds (M2-1) to (M2-27) represented by the formulae (M1-1) to (M1-41) and (M2-1) to (M2-27). In these compounds, R^a、R^b、R^d、Z^M、A^MY and p are as defined in the formulae (M1) and (M2) described in the embodiments of the present invention.

The following partial structures of the compounds (M1-1) to (M1-41) and the compounds (M2-1) to (M2-27) will be explained. Part of the structure (a1) represents a1, 4-phenylene group in which at least one hydrogen is substituted by fluorine. Part of the structure (a2) represents at least one 1, 4-phenylene group which may be substituted by fluorine. Part of the structure (a3) represents a1, 4-phenylene group in which at least one hydrogen may be substituted by either fluorine or a methyl group. The partial structure (a4) represents fluorene in which hydrogen at the 9-position may be substituted with a methyl group.

The monomer having a mesogenic site and three or more polymerizable functional groups can be used for the purpose of optimizing the optical isotropy of the polymer/liquid crystal composite material of the present invention. As the monomer having a mesogenic site and three or more polymerizable functional groups, known compounds such as (M4-1) to (M4-3) can be preferably used, and more specific examples thereof include those described in Japanese patent laid-open Nos. 2000-327623, 2004-182949 and 2004-59772. Wherein in (M4-1) to (M4-3), R^bY, and (F) are as defined above. Za is the same as Z^Mthe same definition.

5-2-2. monomer having polymerizable functional group and having no mesogen portion

examples of the monomer having no mesogenic portion and containing a polymerizable functional group include linear acrylate or branched acrylate having 1 to 30 carbon atoms, and linear diacrylate or branched diacrylate 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, ditrimethylolpropane tetraacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trimethylolpropane triacrylate, and the like, but are not limited to these monomers.

5-2-3 polymerization initiator

The polymerization reaction in the production of the polymer constituting the composite material of the present invention is not particularly limited, and for example, photoradical polymerization, thermal radical polymerization, photocationic 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 polymerization 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), Azobiscyclohexanecarbonitrile (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").

Examples of DAS include: diphenyliodotetrafluoroborate, diphenyliodohexafluorophosphonate, diphenyliodohexafluoroarsenate, diphenyliodotrifluoromethanesulfonate, diphenyliodotrifluoroacetate, diphenyliodopara-toluenesulfonate, diphenyliodotetrakis (pentafluorophenyl) borate, 4-methoxyphenyliodotetrafluoroborate, 4-methoxyphenylphenyliodohexafluorophosphonate, 4-methoxyphenyliodohexafluoroarsenate, 4-methoxyphenylphenyliodotrifluoromethanesulfonate, 4-methoxyphenylphenyliodotrifluoroformate, 4-methoxyphenyliodopara-toluenesulfonate, etc.

The DAS can be also highly sensitive by adding a photosensitizer such as thioxanthone, phenothiazine, chlorothioxanthone, xanthone, anthracene, diphenylanthracene, rubrene, or the like.

Examples of TAS include: triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoroacetate, triphenylsulfonium-p-toluenesulfonate, triphenylsulfonium tetrakis (pentafluorophenyl) borate, 4-methoxyphenyl diphenylsulfonium tetrafluoroborate, 4-methoxyphenyl diphenylsulfonium hexafluorophosphate, 4-methoxyphenyl diphenylsulfonium hexafluoroarsenate, 4-methoxyphenyl diphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyl diphenylsulfonium trifluoroacetate, 4-methoxyphenyl diphenylsulfonium p-toluenesulfonate, etc.

Specific trade names of the photocationic polymerization initiator are, for example, Hilackle (Cyracure) UVI-6990, Hilackle UVI-6974, Hilackle UVI-6992 (trade name, UCC (stock)), Adeka optomer SP-150, SP-152, SP-170, SP-172 (trade name, Adeka (stock)), Rhodoschil Photoinitiator (Rhodorsil Photonitiator) 2074 (trade name, Rhodia Japan) (stock)), Irgacure (IRGACURE)250 (trade name, Nippon Barff (stock)), UV-9380C (trade name, GE Toshiba Silicone (GETABAS (stock)), and the like.

5-2-4 hardening agents and the like

In the production of the polymer constituting the composite material of the present invention, one or more other preferable components, for example, a curing agent, a curing accelerator, a stabilizer, and the like may be further added in addition to the polymerizable monomer and the like and the polymerization initiator.

As the hardener, a conventionally known 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, acid anhydride-based curing agents, and the like. Examples of the amine-based curing agent include: aliphatic polyamines such as diethylenetriamine, triethylenetetramine, tetraethylpentamine, m-xylylenediamine, trimethylhexamethylenediamine, 2-methylpentamethylenediamine, and diethylaminopropylamine; alicyclic polyamines such as isophorone diamine, 1, 3-bisaminomethylcyclohexane, bis (4-aminocyclohexyl) methane, norbornene diamine, 1, 2-diaminocyclohexane, and Laromin (Laromin); aromatic polyamines such as diaminodiphenylmethane, diaminodiphenylethane, and m-phenylenediamine, and the like.

Examples of the novolac-based curing agent include novolac resins and biphenol novolac resins. Examples of the imidazole-based curing agent include: 2-methylimidazole, 2-ethylhexylimidazole, 2-phenylimidazole, 1-cyanoethyl-2-phenylimidazolium trimellitate, and the like.

Examples of the acid anhydride-based curing agent include: tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylcyclohexene tetracarboxylic dianhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, and the like.

further, 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 can be 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 or organic acid salts thereof, quaternary ammonium salts such as tetraethylammonium bromide and tetrabutylammonium bromide, and boron compounds such as boron trifluoride and triphenylborate. The hardening accelerator may be used alone or in combination of two or more.

In addition, for example, in order to prevent undesired polymerization during storage, a stabilizer is preferably added. As stabilizers, use may be made of all compounds known to the person skilled in the art. Typical examples of the stabilizer include: 4-ethoxyphenol, hydroquinone, Butylated Hydroxytoluene (BHT), and the like.

5-3. composition of polymer/liquid crystal composite material

The content of the liquid crystal composition in the polymer/liquid crystal composite material of the present invention is preferably as high as possible as long as the composite material can exhibit an optically isotropic liquid crystal phase. The reason for this is that: the higher the content of the liquid crystal composition, the larger the electric double refraction value of the composite material of the present invention.

In the polymer/liquid crystal composite material of the present invention, the content of the liquid crystal composition is preferably 60 to 99% by weight, more preferably 60 to 98% by weight, and particularly preferably 80 to 97% by weight, based on the composite material. In the polymer/liquid crystal composite material of the present invention, the content of the polymer is preferably 1 to 40% by weight, more preferably 2 to 40% by weight, and particularly preferably 3 to 20% by weight, based on the composite material.

6. Light conversion element

As will be described in detail in examples below, the cell obtained as an element to which voltage was applied in a direction perpendicular to the electrode surface was sandwiched between two electrode-carrying glass substrates that were not subjected to alignment treatment, and was heated to the blue phase. In this state, ultraviolet light is irradiated to perform a polymerization reaction. The polymer/liquid crystal composite (PSBP-a1) obtained in this manner maintained an optically isotropic liquid crystal phase even when cooled to room temperature. The unit having the polymer/liquid crystal composite sandwiched therebetween is used as a light conversion element.

as an element to which a voltage is applied in the horizontal direction with respect to the electrode surface, the liquid crystal composition was sandwiched between a comb-shaped electrode substrate to which no alignment treatment was applied and a counter glass substrate (no electrode was applied), and the obtained cell was heated to the blue phase. In this state, ultraviolet light is irradiated to perform a polymerization reaction. The polymer/liquid crystal composite material obtained in this way maintains an optically isotropic liquid crystal phase even when cooled to room temperature. The unit having the polymer/liquid crystal composite sandwiched therebetween is used as a light conversion element.

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