Cholesteric liquid crystal composition

Abstract

To provide a liquid crystal composition that makes it possible to manufacture a cholesteric liquid crystal element exhibiting high contrast and a reduced response time.SOLUTION: A cholesteric liquid crystal composition comprises: a host liquid crystal composition containing a specific compound as a first component; at least one optically active compound selected from specific compounds as a first additive; and at least one polymerizable compound selected from specific compounds as a second additive, where, based on a mass of the host liquid crystal composition, a content of the second additive is less than 2.0 mass%.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a cholesteric liquid crystal composition. [Background technology]

[0002] Liquid crystal elements containing liquid crystal compositions that exhibit a "cholesteric phase" are known. This cholesteric phase is a liquid crystal phase in which the orientational order of the molecules rotates in a helical fashion. The helical axis is perpendicular to the direction of the orientational order. The helical period is called the "pitch." Liquid crystal compositions that exhibit a cholesteric phase selectively reflect circularly polarized light, and the direction of rotation of the light vector corresponds to the handedness of the cholesteric helix. The reflected wavelength λ can be calculated from the cholesteric helix pitch P and the average birefringence index n of the cholesteric liquid crystal using equation (A). λ=n×P (A)

[0003] The pitch also depends on, for example, the type of optically active compound in the liquid crystal composition or its concentration. For example, Patent Document 1 discloses a cholesteric liquid crystal composition containing an optically active compound having an octahydrobinaphthalene skeleton.

[0004] The most common cholesteric liquid crystal devices are SSCT (surface stabilized cholesteric texture) and PSCT (polymer stabilized cholesteric texture) devices. SSCT and PSCT devices form cholesteric liquid crystal compositions that initially exhibit a planar structure that reflects light of a specific wavelength in the absence of an applied voltage, and can be switched to a focal conic light-scattering structure by applying an alternating current pulse, or vice versa.

[0005] These liquid crystal devices are bistable, meaning that after the electric field is switched off, each state is maintained and only the re-application of the electric field causes a transition back to the initial state. When a higher voltage pulse is applied, the cholesteric liquid crystal composition transitions to a homeotropically aligned, transparent state, from which it relaxes to a planar state if the voltage is switched off quickly, or to a focal conic state if the voltage is switched off slowly. The minimum drive voltage required to return from the planar state (reflective) to the homeotropic phase (transmissive) is called the Vreset voltage. The lower this drive voltage, the less power consumed.

[0006] Cholesteric liquid crystal devices generally do not require a backlight. In the planar orientation, the cholesteric liquid crystal composition in a pixel selectively reflects light of a specific wavelength according to formula (A) above, resulting in the pixel appearing as a corresponding reflected color, for example, against a black background. This reflected color disappears upon transition to a scattering state due to the focal conic structure or a homeotropic transparent state. Because cholesteric liquid crystal devices display color in the planar state, it is particularly important to stably maintain the planar structure when no voltage is applied in order to achieve good contrast. Furthermore, a short response time is required to display moving images. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Publication No. 2021-152137 Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a liquid crystal composition that enables the production of a cholesteric liquid crystal device having a higher contrast and a shorter response time. [Means for solving the problem]

[0009] As a result of extensive research, the inventors have found that a liquid crystal composition containing an optically active compound, a liquid crystal compound having a cyano group, and a polymerizable compound having a predetermined amount of mesogenic moieties can solve the above-mentioned problems, and have completed the present invention.

[0010] The present invention includes the following items.

[0011] Item 1. A host liquid crystal composition containing at least one compound selected from the compounds represented by formula (1) as a first component, and at least one optically active compound selected from the compounds represented by formula (Ch1) and formula (Ch2) as a first additive, and at least one polymerizable compound selected from the compounds represented by formula (M1) as a second additive, A cholesteric liquid crystal composition, wherein the content of the second additive is less than 2.0% by weight based on the weight of the host liquid crystal composition. [ka] In formula (1), R 11 is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms; ring A 1 is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl; Z 11 is a single bond, carbonyloxy, or difluoromethyleneoxy; X 11 and X 12 is hydrogen or fluorine; n1 is 1 or 2; In formula (Ch1) and formula (Ch2), R 1 , R 2 , and R 3is hydrogen, halogen, cyano, -SF5, or alkyl having 1 to 10 carbon atoms, in which at least one -CH2- may be replaced by -O-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups at least one hydrogen may be replaced by fluorine or chlorine; ring A, ring B, ring E, and ring F are 5,6,7,8-tetrahydronaphthalene-1,2-diyl or naphthalene. ring C, ring D, and ring G are 1,4-cyclohexylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl, tetrahydropyran-3,5-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, or 1,4-bicyclo-(2,2,2)-octylene, in which at least one hydrogen may be replaced by fluorine or chlorine; Z 1 , Z 2 , Z 3 , Z 4 , and Z 5 represents a single bond or alkylene having 1 to 20 carbon atoms, in which at least one -CH2- may be replaced by -O-, -CO-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups at least one hydrogen may be replaced by fluorine or chlorine; a, b, and c are 2, 3, or 4; In formula (M1), R a and R b is a polymerizable group represented by any one of formulas (P-1) to (P-6), hydrogen, halogen, -C≡N, -N=C=O, or -N=C=S, and R a and R b at least one of the above is the polymerizable group, [ka] In formulas (P-1) to (P-6), M 1 From M 3 is hydrogen, fluorine, alkyl having 1 to 5 carbon atoms, or alkyl having 1 to 5 carbon atoms in which at least one hydrogen atom is replaced by fluorine, and M1 From M 3 In the formula (I), at least one -CH2- in the alkyl may be replaced by -O-; M1 and A M2 is a divalent group obtained by removing two hydrogen atoms from a ring having aromaticity, and in these rings, at least one hydrogen atom may be replaced by a halogen atom, an alkyl having 1 to 5 carbon atoms, a halogenated alkyl having 1 to 5 carbon atoms, an alkyl having 1 to 5 carbon atoms in which at least one —CH— is replaced by —O— or —COO—, a polymerizable group represented by any of formulas (P-1) to (P-6), an alkyl having 1 to 5 carbon atoms in which at least one hydrogen atom is replaced by a polymerizable group represented by any of formulas (P-1) to (P-6), or a halogenated alkyl having 1 to 5 carbon atoms in which at least one hydrogen atom is replaced by a polymerizable group represented by any of formulas (P-1) to (P-6); Y M1 and Y M2 represents a single bond or alkylene having 1 to 12 carbon atoms, in which at least one -CH2- may be replaced by -O- or -S-, and at least one -CH2-CH2- may be replaced by -CH=CH-, -C≡C-, -COO-, or -OCO-; Y M1 and Y M2 at least one of is a single bond or an alkylene having 1 to 4 carbon atoms, in which at least one -CH2- may be replaced by -O-; Z M is a single bond, -(CH2) m2 -, -O(CH2) m2 -, -(CH2) m2 O-, -O(CH2) m2O—, —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- (wherein m2 is 1 or 2); and m1 is an integer from 1 to 5.

[0012] Item 2. Formula (M1) contains two or three polymerizable groups represented by any one of formulas (P-1) to (P-6), and R a and R b are polymerizable groups represented by any one of formulas (P-1) to (P-6). Item 3. The cholesteric liquid crystal composition according to item 1 or 2, wherein the total content of polymerizable compounds is less than 2.0% by mass based on the mass of the host liquid crystal composition. Section 4.Y M1 and Y M2 represents a single bond or alkylene having 1 to 8 carbon atoms, in which at least one -CH2- may be replaced by -O- or -S-, and at least one -CH2-CH2- may be replaced by -CH=CH-, -C≡C-, -COO-, or -OCO-; Y M1 and Y M2 Item 4. The cholesteric liquid crystal composition according to any one of items 1 to 3, wherein at least one of the -CH2- groups is a single bond or an alkylene group having 1 to 4 carbon atoms in which at least one -CH2- group may be replaced by -O-.

[0013] Item 5. The cholesteric liquid crystal composition according to any one of items 1 to 4, further comprising at least one polymerizable compound selected from the compounds represented by formulae (M1-1) to (M1-5) as a second additive. [ka] In formulas (M1-1) to (M1-5), R a , R b , Y, Z M is R in formula (M1) a , R b , Y, Z M are synonymous with X M1 is a halogen, an alkyl having 1 to 5 carbon atoms, a halogenated alkyl having 1 to 5 carbon atoms, an alkyl having 1 to 5 carbon atoms in which at least one -CH2- is replaced by -O- or -COO-, a polymerizable group represented by any one of formulas (P-1) to (P-6), an alkyl having 1 to 5 carbon atoms in which at least one hydrogen is replaced by a polymerizable group represented by any one of formulas (P-1) to (P-6), or a halogenated alkyl having 1 to 5 carbon atoms in which at least one hydrogen is replaced by a polymerizable group represented by any one of formulas (P-1) to (P-6), and X M2 is hydrogen or methyl; f is 0, 1, 2, 3, or 4; g is 0, 1, 2, or 3; and h is 0, 1, or 2.

[0014] Item 6. The cholesteric liquid crystal composition according to any one of items 1 to 5, wherein the content of the polymerization initiator is 0.1% by mass or less based on the mass of the host liquid crystal composition.

[0015] Item 7. The cholesteric liquid crystal composition according to any one of items 1 to 6, containing at least one optically active compound selected from the compounds represented by formulas (Ch1-1) to (Ch1-6) and formulas (Ch2-1) to (Ch2-3) as a first additive. [ka]

[0016] [ka] In formulas (Ch1-1) to (Ch1-6) and formulas (Ch2-1) to (Ch2-3), R 1 , R2 , and R 3 is hydrogen, halogen, cyano, —SF5, or alkyl having 1 to 10 carbon atoms, in which at least one —CH2— may be replaced by —O—, —COO—, —OCO—, —CH═CH—, or —C≡C—, and in these groups, at least one hydrogen may be replaced by fluorine or chlorine; ring A, ring B, ring E, and ring F are 5,6,7,8-tetrahydronaphthalene-1,2-diyl or naphthalene-1,2-diyl.

[0017] Item 8. The cholesteric liquid crystal composition according to any one of items 1 to 7, wherein the content of the first additive is in the range of 0.1% by mass to 10% by mass, based on the mass of the host liquid crystal composition.

[0018] Item 9. The cholesteric liquid crystal composition according to any one of items 1 to 8, comprising at least one compound selected from the compounds represented by formula (1-1) to formula (1-9) as a first component: [ka] In formulas (1-1) to (1-9), R 11 is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms; X 11 and X 12 is hydrogen or fluorine.

[0019] Item 10. The cholesteric liquid crystal composition according to any one of items 1 to 9, wherein the content of the first component is in the range of 5% by mass to 30% by mass based on the mass of the host liquid crystal composition.

[0020] Item 11. The cholesteric liquid crystal composition according to any one of items 1 to 10, wherein the host liquid crystal composition further contains at least one compound selected from the compounds represented by formula (2) as a second component: [ka] In equation (2), R 21 is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms; 2 is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; Z 21 is a single bond, ethylene, vinylene, carbonyloxy, or difluoromethyleneoxy; X 21 and X 22 is hydrogen or fluorine; Y 21 is fluorine, chlorine, alkyl having 1 to 12 carbon atoms in which at least one hydrogen has been replaced by fluorine or chlorine, alkoxy having 1 to 12 carbon atoms in which at least one hydrogen has been replaced by fluorine or chlorine, or alkenyloxy having 2 to 12 carbon atoms in which at least one hydrogen has been replaced by fluorine or chlorine; and n2 is 1, 2, 3, or 4.

[0021] Item 12. The cholesteric liquid crystal composition according to item 11, comprising at least one compound selected from the compounds represented by formulas (2-1) to (2-38) as a second component: [ka]

[0022] [ka]

[0023] [ka]

[0024] [ka]

[0025] [ka] In equations (2-1) to (2-38), R 21 is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms.

[0026] Item 13. The cholesteric liquid crystal composition according to item 11 or 12, wherein the content of the second component is in the range of 5% by mass to 50% by mass based on the mass of the host liquid crystal composition.

[0027] Item 14. The cholesteric liquid crystal composition according to any one of items 1 to 13, wherein the host liquid crystal composition further contains at least one compound selected from the compounds represented by formula (3) as a third component: [ka] In equation (3), R 31 and R 32 is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine; 3 and ring D 3 is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z 31 is a single bond, ethylene, vinylene, ethynylene, methyleneoxy, or carbonyloxy; and n3 is 1, 2, or 3.

[0028] Item 15. The cholesteric liquid crystal composition according to item 14, further comprising at least one compound selected from the compounds represented by formula (3-1) to formula (3-20) as a third component: [ka]

[0029] [ka] In equations (3-1) to (3-20), R 31 and R 32 is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms in which at least one hydrogen has been replaced by fluorine or chlorine.

[0030] Item 16. The cholesteric liquid crystal composition according to item 14 or 15, wherein the content of the third component is in the range of 10% by mass to 90% by mass based on the mass of the host liquid crystal composition. Item 17. The cholesteric liquid crystal composition according to any one of items 1 to 16, wherein the host liquid crystal composition has an optical anisotropy at a wavelength of 589 nm (measured at 25°C) in the range of 0.10 to 0.40, and a dielectric anisotropy at a frequency of 1 kHz (measured at 25°C) in the range of 10 to 100. Item 18. The cholesteric liquid crystal composition according to any one of items 1 to 17, wherein the selective reflection wavelength is in the range of 350 to 800 nm. [Effects of the Invention]

[0031] The present invention provides a liquid crystal composition that enables the production of cholesteric liquid crystal devices with higher contrast and shorter response times. DETAILED DESCRIPTION OF THE INVENTION

[0032] The terms used in this specification are as follows. The terms "liquid crystal composition" and "liquid crystal element" may be abbreviated as "composition" and "element," respectively. "Liquid crystal element" is a general term for liquid crystal display panels, liquid crystal display modules, liquid crystal devices, etc. that use liquid crystal compositions. "Liquid crystal compound" is a general term for compounds that have a liquid crystal phase, such as a nematic phase, cholesteric phase, or smectic phase, and compounds that do not have a liquid crystal phase but are mixed into a composition for the purpose of adjusting properties such as the temperature range, viscosity, and dielectric anisotropy of the liquid crystal phase. This compound has a six-membered ring, such as 1,4-cyclohexylene or 1,4-phenylene, and its molecular structure is rod-like.

[0033] The compounds in this specification will be explained using the following compound (1z) as an example. [ka] In formula (1z), the symbols α and β enclosed in a hexagon correspond to ring α and ring β, respectively, and represent rings such as six-membered rings and fused rings. When the subscript 'x' is 2, two rings α exist. The two groups represented by the two rings α may be the same or different. This rule applies to any two rings α when the subscript 'x' is greater than 2. This rule also applies to other symbols, such as the bonding group Z. A diagonal line across one side of ring β indicates that any hydrogen on ring β may be replaced with a substituent (-Sp-P). The subscript 'y' indicates the number of replaced substituents. When the subscript 'y' is 0, there is no such replacement. When the subscript 'y' is 2 or greater, there are multiple substituents (-Sp-P) on ring β. In this case, the "may be the same or different" rule also applies. Note that this rule also applies when the symbol Ra is used for multiple compounds.

[0034] In formula (1z), for example, an expression such as "Ra and Rb are alkyl, alkoxy, or alkenyl" means that Ra and Rb are independently selected from the group of alkyl, alkoxy, and alkenyl, where the group represented by Ra and the group represented by Rb may be the same or different.

[0035] At least one compound selected from the compounds represented by formula (1z) may be abbreviated as "compound (1z)." "Compound (1z)" means one compound represented by formula (1z), a mixture of two compounds, or a mixture of three or more compounds. The same applies to compounds represented by other formulas. The expression "at least one compound selected from the compounds represented by formula (1z) and formula (2z)" means at least one compound selected from the group consisting of compound (1z) and compound (2z). Similarly, expressions such as "at least one compound selected from the compounds represented by formula (1z) to formula (3z)" mean at least one compound selected from the group consisting of compound (1z), compound (2z), and compound (3z).

[0036] The expression "at least one 'A'" means that the number of 'A' is arbitrary. The expression "at least one 'A' may be replaced with 'B'" means that when there is one 'A', the position of 'A' is arbitrary, and when there are two or more 'As', their positions can be selected without restriction. The expression "at least one -CH2- may be replaced with -O-" is sometimes used. In this case, -CH2-CH2-CH2- may be converted to -O-CH2-O- by replacing non-adjacent -CH2- with -O-. However, adjacent -CH2- cannot be replaced with -O- because this replacement would produce -OO-CH2- (peroxide).

[0037] The alkyl of the liquid crystal compound is linear or branched, and does not include cyclic alkyl. Linear alkyl is preferred to branched alkyl. The same applies to terminal groups such as alkoxy and alkenyl. The trans configuration of 1,4-cyclohexylene is preferred over cis to increase the maximum temperature. 2-Fluoro-1,4-phenylene is asymmetric, so it exists in left-facing (L) and right-facing (R) configurations. [ka] The same applies to divalent groups such as tetrahydropyran-2,5-diyl, and to linking groups such as carbonyloxy (-COO- or -OCO-).

[0038] Liquid crystal compositions are prepared by mixing multiple liquid crystal compounds. Additives such as optically active compounds, antioxidants, UV absorbers, dyes, antifoaming agents, polymerizable compounds, polymerization initiators, and polymerization inhibitors may be added to the liquid crystal composition as needed. In relation to these additives, the liquid crystal composition is sometimes referred to as a "host liquid crystal composition," or, together with the type of liquid crystal phase, as a "host nematic liquid crystal composition." Furthermore, each liquid crystal compound in a "host liquid crystal composition" is sometimes referred to as a "component compound." The proportion (content) of the liquid crystal compound is expressed as a mass percentage (mass%) based on the mass of the host liquid crystal composition. The proportion (addition amount) of an additive is expressed as a mass percentage relative to the mass of the host liquid crystal composition. Note that parts per million (ppm) may be used for some additives.

[0039] The proportion of the liquid crystal compound or additive or additives contained in the composition can be determined by analyzing the mixture of liquid crystal compounds by gas chromatography using a flame ionization detector (FID). The area ratio of the peaks in the gas chromatogram corresponds to the proportion of the liquid crystal compound.

[0040] In this specification, a liquid crystal composition that is produced by adding an optically active compound to a host liquid crystal composition that exhibits a nematic phase and that exhibits a "cholesteric phase" is referred to as a "cholesteric liquid crystal" or a "cholesteric liquid crystal composition."

[0041] The "maximum temperature of a nematic or cholesteric phase" may be abbreviated as the "maximum temperature." The "minimum temperature of a nematic or cholesteric phase" may be abbreviated as the "minimum temperature." "High resistivity" means that the composition has high resistivity not only at room temperature but also at temperatures close to the maximum temperature of the cholesteric phase in the initial stage, and that after prolonged use, it has high resistivity not only at room temperature but also at temperatures close to the maximum temperature of the cholesteric phase. "High voltage holding ratio" means that the element has high voltage holding ratio not only at room temperature but also at temperatures close to the maximum temperature of the cholesteric phase in the initial stage, and that after prolonged use, it has high voltage holding ratio not only at room temperature but also at temperatures close to the maximum temperature of the cholesteric phase.

[0042] The cholesteric liquid crystal composition of the present invention has suitable properties, and by improving the properties of this composition, a liquid crystal device having good properties can be obtained. The ratio of the reflectance of a cholesteric liquid crystal composition in the planar state to that in the focal conic state is related to the contrast of the cholesteric liquid crystal device. As shown in the examples, this reflectance ratio can be determined by dividing the reflectance when a high voltage is applied and then turned off by the reflectance when a low voltage is applied and then turned off. A large ratio is preferred. The viscosity of the composition is related to the response time of the device. A short response time is preferable for displaying moving images on the device. A response time shorter than even 1 millisecond is desirable. Therefore, a low viscosity of the composition is preferable. The viscosity at 25°C is preferably 120 mPa·s or less, and more preferably 80 mPa·s or less. A low viscosity at low temperatures is even more preferable. The helical pitch length of the composition is preferably such that the reflection wavelength can be adjusted to the visible region with as little added amount of optically active compound as possible so as not to impair the properties of the host nematic liquid crystal composition.Furthermore, it is preferable that the temperature dependence of the helical pitch length is almost zero or small so as not to deteriorate the display quality due to changes in environmental temperature.

[0043] The temperature range of the cholesteric phase is related to the temperature range in which the device can be used. The preferred upper limit temperature of the cholesteric phase is about 70°C or higher, and the preferred lower limit temperature of the cholesteric phase is about -10°C or lower. A high resistivity in a composition contributes to a high voltage holding ratio in the device. Therefore, a composition having a high resistivity not only at room temperature but also at temperatures close to the upper limit temperature of the cholesteric phase is preferred. A composition having a high resistivity not only at room temperature but also at temperatures close to the upper limit temperature of the cholesteric phase after long-term use is preferred. The resistivity of the liquid crystal composition at room temperature is preferably 1×10 10 Ω·cm or more, and more preferably 1×10 12 Ω·cm or more, and more preferably 1×10 14 Ω·cm or more.

[0044] The optical anisotropy of a composition is related to a bright display. To achieve a bright display, a liquid crystal composition with a relatively large optical anisotropy is required. The optical anisotropy at a wavelength of 589 nm (measured at 25°C) of the host liquid crystal composition is preferably in the range of 0.10 to 0.40, more preferably in the range of 0.12 to 0.35, and even more preferably in the range of 0.15 to 0.30. A relatively large dielectric anisotropy in a composition contributes to a low driving voltage in a device, so a relatively large dielectric anisotropy is preferred. The dielectric anisotropy at a frequency of 1 kHz (measured at 25°C) of the host liquid crystal composition is preferably in the range of 10 to 100, more preferably in the range of 10 to 60, even more preferably in the range of 15 to 55, and particularly preferably in the range of 20 to 50.

[0045] The cholesteric liquid crystal composition of the present invention will be described in the following order. First, the composition structure will be described. Second, the main properties of the additives and component compounds in the host liquid crystal composition, as well as the main effects of these compounds on the cholesteric liquid crystal composition and device, will be described. Third, the combination and ratio of the additives and component compounds in the composition will be described. Fourth, preferred forms of the additives and component compounds will be described. Fifth, preferred additives and component compounds will be shown. Sixth, additives that may be added to the composition will be described. Seventh, methods for synthesizing the additives and component compounds will be described. Finally, uses of the composition will be described.

[0046] First, the constitution of the cholesteric liquid crystal composition of the present invention will be explained. The cholesteric liquid crystal composition of the present invention contains a host liquid crystal composition containing at least one compound selected from the compounds represented by formula (1) as a first component, at least one optically active compound selected from the compounds represented by formula (Ch1) and formula (Ch2) as a first additive, and at least one polymerizable compound selected from the compounds represented by formula (M1) as a second additive. In the cholesteric liquid crystal composition of the present invention, the content of the second additive is less than 2.0% by mass based on the mass of the host liquid crystal composition.

[0047] The composition of the present invention may further contain other liquid crystal compounds, other additives, etc. "Other liquid crystal compounds" are liquid crystal compounds other than compound (1), such as the second component and third component described below. "Other additives" are additives other than compound (Ch1), compound (Ch2), or compound (M1), which are mixed into the composition for the purpose of further adjusting the properties. Other additives include antioxidants, ultraviolet absorbers, dyes, antifoaming agents, polymerizable compounds, polymerization initiators, polymerization inhibitors, polar compounds, etc.

[0048] Secondly, the main properties of the additives and the component compounds in the host liquid crystal composition, as well as the main effects of these compounds on the cholesteric liquid crystal composition and device, are explained. The optically active compound, compound (Ch1) or compound (Ch2) (first additive), is added to a host nematic liquid crystal composition to produce a cholesteric phase. Therefore, the structures of compound (Ch1) and compound (Ch2) are not racemic. Compound (Ch1) or compound (Ch2) can be produced by the method described in International Publication No. 2014 / 097952. The cholesteric liquid crystal composition of the present invention uses compound (Ch1) or compound (Ch2) as the optically active compound, and therefore has a reflection wavelength in the visible region with a small amount of the optically active compound added. Furthermore, the helical pitch length exhibits little temperature dependence.

[0049] The compound represented by compound (M1) contributes to improving contrast when added to the composition in a predetermined amount.

[0050] The cholesteric liquid crystal composition of the present invention contains the compound (1) as the first component in the host liquid crystal composition, which allows the viscosity to be low, the response time of the device to be short, and the driving voltage to be reduced. The main properties of the first component and other component compounds in the host liquid crystal composition are summarized in Table 1 based on the effects of the present invention. In the symbols in Table 1, L means large or high, M means medium, and S means small or low. The symbols L, M, and S are classifications based on qualitative comparison between the component compounds, and 0 (zero) means extremely small.

[0051] [Table 1]

[0052] The main effects of the component compounds on the properties of the composition are as follows: the first component compound (1) decreases the viscosity and increases the dielectric anisotropy; the second component compound (2) increases the dielectric anisotropy; and the third component compound (3) decreases the viscosity, increases the optical anisotropy, and increases the maximum temperature or decreases the minimum temperature.

[0053] Third, the combination and proportion of additives and component compounds in the composition will be described. The composition contains at least a combination of Compound (1) + Compound (Ch1) or Compound (Ch2) + Compound (M1). Also preferred are Compound (1) + Compound (Ch1) or Compound (Ch2) + Compound (M1) + Compound (2), Compound (1) + Compound (Ch1) or Compound (Ch2) + Compound (M1) + Compound (3), or Compound (1) + Compound (Ch1) or Compound (Ch2) + Compound (M1) + Compound (2) + Compound (3). More preferred is Compound (1) + Compound (Ch1) or Compound (Ch2) + Compound (M1) + Compound (2) + Compound (3).

[0054] The preferred addition ratio of compound (Ch1) or compound (Ch2) based on the mass of the host liquid crystal composition is 0.1 mass% or more to obtain a stable twist state in the cholesteric liquid crystal composition, and 10 mass% or less to avoid impairing the properties of the host nematic liquid crystal composition. The more preferred addition ratio is in the range of 0.5 to 7 mass%, and the most preferred addition ratio is in the range of 1 to 5 mass%.

[0055] The content of compound (M1) in the composition is less than 2.0% by mass based on the mass of the host liquid crystal composition. The inventors have discovered that cholesteric liquid crystal compositions containing less than 2.0% by mass of compound (M1), a polymerizable compound having a specific structure, provide high contrast. The content of compound (M1) is sufficient to be 0.1% by mass or more, preferably 0.2% by mass or more. Cholesteric liquid crystal compositions provide particularly high contrast when the content of compound (M1) is 0.3% to 1.5% by mass. When the cholesteric liquid crystal composition contains a polymerizable compound other than compound (M1), particularly when it contains a polymerizable compound having a polymerizable group represented by any of formulas (P-1) to (P-6), the total content of compound (M1) and the polymerizable compounds other than compound (M1) is preferably less than 2.0% by mass based on the mass of the host liquid crystal composition. In this case, the compound (M1) is contained in an amount of at least 0.2% by mass or more, preferably 0.3% by mass or more, based on the mass of the host liquid crystal composition, and the content of the compound (M1) is preferably 50% by mass or more, more preferably 60% by mass or more, and even more preferably 70% by mass or more, based on the mass of the total content of the polymerizable compounds.

[0056] Based on the mass of the host liquid crystal composition, the proportion of the first component, compound (1), is preferably 5 mass% or more to reduce viscosity and increase dielectric anisotropy. It is also preferably 30 mass% or less. A more preferred proportion is in the range of 10 to 25 mass%, and a particularly preferred proportion is in the range of 10 to 20 mass%.

[0057] When the host liquid crystal composition contains the second component, a preferred ratio of the compound (2) as the second component is 5% by mass or more, based on the mass of the host liquid crystal composition, for increasing the dielectric anisotropy, and 50% by mass or less for avoiding increasing the viscosity or the minimum temperature.

[0058] When the host liquid crystal composition contains a third component, the proportion of the third component, compound (3), is preferably 10% by mass or more based on the mass of the host liquid crystal composition to reduce viscosity or adjust optical anisotropy, and 90% by mass or less to prevent reduction of dielectric anisotropy. A more preferred proportion is in the range of 30 to 85% by mass. A particularly preferred proportion is in the range of 45 to 80% by mass.

[0059] Fourth, preferred forms of additives and component compounds will be explained.

[0060] Preferred forms of the compounds represented by formula (Ch1) and formula (Ch2), which are the first additives, are described below. 1 , R 2 , and R 3 is hydrogen, halogen, cyano, -SF5, or alkyl having 1 to 10 carbon atoms, in which at least one -CH2- may be replaced by -O-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups at least one hydrogen may be replaced by fluorine or chlorine. 1 , R 2 , or R 3 is alkyl having 1 to 10 carbon atoms. Ring A, ring B, ring E, and ring F are 5,6,7,8-tetrahydronaphthalene-1,2-diyl or naphthalene-1,2-diyl. Preferred ring A or ring B is 5,6,7,8-tetrahydronaphthalene-1,2-diyl, and preferred ring E or ring F is naphthalene-1,2-diyl. Ring C, ring D, and ring G are 1,4-cyclohexylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl, tetrahydropyran-3,5-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, or 1,4-bicyclo-(2,2,2)-octylene, and in these rings, at least one hydrogen may be replaced by fluorine or chlorine. Preferred ring C, ring D, or ring G is 1,4-cyclohexylene or 1,4-phenylene. 1 , Z 2 , Z3 , Z 4 , and Z 5 is a single bond or an alkylene having 1 to 20 carbon atoms, in which at least one -CH2- may be replaced by -O-, -CO-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups at least one hydrogen may be replaced by fluorine or chlorine. 1 , Z 2 , Z 3 , Z 4 , or Z 5 is a single bond or —OCO—. a, b, and c are 2, 3, or 4. Preferably, a, b, or c is 2 or 3.

[0061] A preferred embodiment of the compound represented by formula (M1), which is the second additive, is described below. a and R b is a polymerizable group represented by any one of formulas (P-1) to (P-6) (hereinafter referred to as "polymerizable group represented by formulas (P-1) to (P-6)"), hydrogen, halogen, -C≡N, -N=C=O, or -N=C=S, and R a and R b At least one of the groups is the polymerizable group. [ka]

[0062] In formulas (P-1) to (P-6), M 1 From M 3 is hydrogen, fluorine, alkyl having 1 to 5 carbon atoms, or alkyl having 1 to 5 carbon atoms in which at least one hydrogen atom is replaced by fluorine, and M 1 From M 3 In the above, at least one -CH2- in the alkyl may be replaced with -O-. a or R b is a polymerizable group represented by formula (P-1). 1 , M 2 , or M 3 is hydrogen, fluorine, or methyl.

[0063] In formula (M1), A M1 and A M2 is a divalent group obtained by removing two hydrogen atoms from an aromatic ring. Examples of divalent groups obtained by removing two hydrogen atoms from an aromatic ring include 1,4-phenylene, naphthalene-2,6-diyl, tetrahydronaphthalene-2,6-diyl, phenanthrene-2,7-diyl, and fluorene-2,7-diyl, in which at least one -CH2- group in the ring may be replaced with -O-, and at least one -CH= group in the ring may be replaced with -N=. In these rings, at least one hydrogen may be replaced with a halogen, an alkyl having 1 to 5 carbon atoms, an alkyl having 1 to 5 carbon atoms in which at least one hydrogen has been replaced with a halogen (halogenated alkyl having 1 to 5 carbon atoms), an alkyl having 1 to 5 carbon atoms in which at least one -CH2- has been replaced with -O- or -COO-, a polymerizable group represented by any of formulas (P-1) to (P-6), an alkyl having 1 to 5 carbon atoms in which at least one hydrogen has been replaced with a polymerizable group represented by any of formulas (P-1) to (P-6), or a halogenated alkyl having 1 to 5 carbon atoms in which at least one hydrogen has been replaced with a polymerizable group represented by any of formulas (P-1) to (P-6). M1 or A M2 is 1,4-phenylene or fluorene-2,7-diyl, and in these rings, at least one hydrogen may be replaced by fluorine, alkyl having 1 to 5 carbon atoms, or a polymerizable group represented by formula (P-1).

[0064] In formula (M1), Y M1 and Y M2 represents a single bond or an alkylene having 1 to 12 carbon atoms, in which at least one -CH2- may be replaced by -O- or -S-, and at least one -CH2-CH2- may be replaced by -CH=CH-, -C≡C-, -COO-, or -OCO-; Y M1 and Y M2At least one of Y is a single bond or an alkylene having 1 to 4 carbon atoms in which at least one -CH2- may be replaced by -O-. In this way, the polymerizable group and the ring structure are directly bonded, or the chain length of the bonding group between the polymerizable group and the ring structure is relatively short, such as an alkylene having 1 to 4 carbon atoms in which at least one -CH2- may be replaced by -O-, and therefore, it is believed that the compound (M1) enhances the stability of the cholesteric composition when it is in a planar structure state. Furthermore, Y M1 and Y M2 At least one of these is preferably a single bond or alkylene having 4 carbon atoms in which at least one -CH2- is replaced with -O-.

[0065] In formula (M1), Z M is a single bond, -(CH2) m2 -, -O(CH2) m2 -, -(CH2) m2 O-, -O(CH2) m2 O-, -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-, and m2 is 1 or 2. Preferred Z M is a single bond, -C≡C-, -COO-, or -OCO-. m1 is an integer of 1 to 5, preferably an integer of 1 to 3, more preferably 1 or 2, and even more preferably 2. In particular, in compound (M1), A M1 and A M2 When both are 1,4-phenylene, m1 is preferably 2.

[0066] In formulas (M1-1) to (M1-5), R a , R b , Y, Z Mis R in formula (M1) a , R b , Y, Z M are synonymous with each other. X M1 is a halogen, an alkyl having 1 to 5 carbon atoms, a halogenated alkyl having 1 to 5 carbon atoms, an alkyl having 1 to 5 carbon atoms in which at least one -CH2- is replaced with -O- or -COO-, a polymerizable group represented by any one of formulas (P-1) to (P-6), an alkyl having 1 to 5 carbon atoms in which at least one hydrogen is replaced with a polymerizable group represented by any one of formulas (P-1) to (P-6), or a halogenated alkyl having 1 to 5 carbon atoms in which at least one hydrogen is replaced with a polymerizable group represented by any one of formulas (P-1) to (P-6). M1 is fluorine, alkyl having 1 to 5 carbon atoms, or a polymerizable group represented by any one of formulas (P-1) to (P-6). M2 is hydrogen or methyl; f is 0, 1, 2, 3, or 4; g is 0, 1, 2, or 3; and h is 0, 1, or 2.

[0067] The compound (M1) is a polymerizable compound. The number of polymerizable groups represented by formulas (P-1) to (P-6) contained in the formula (M1) is preferably two or three, and more preferably two. a and R b are preferably polymerizable groups represented by formula (P-1) to formula (P-6). All of the polymerizable groups contained in formula (M1) are preferably polymerizable groups represented by formula (P-1).

[0068] The preferred forms of the compounds represented by formula (1), (2), and (3), which are component compounds in the host liquid crystal composition, are described below. 11 is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms. 11 is an alkyl having 1 to 12 carbon atoms to increase stability, or an alkenyl having 2 to 12 carbon atoms to decrease viscosity. 21is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms. 21 is an alkyl having 1 to 12 carbon atoms to increase stability. 31 and R 32 is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine. 31 or R 32 is an alkyl having 1 to 12 carbon atoms to increase stability, and an alkenyl having 2 to 12 carbon atoms to decrease viscosity.

[0069] Preferred alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, and octyl, and more preferred alkyl groups are methyl, ethyl, propyl, butyl, and pentyl for decreasing the viscosity.

[0070] Preferred alkoxy is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, or heptyloxy. For decreasing the viscosity, more preferred alkoxy is methoxy or ethoxy.

[0071] Preferred alkenyls are 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, and 5-hexenyl. More preferred alkenyls are vinyl, 1-propenyl, 3-butenyl, and 3-pentenyl for reducing viscosity. The preferred configuration of -CH=CH- in these alkenyls depends on the position of the double bond. For reducing viscosity, trans is preferred for alkenyls such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, and 3-hexenyl. Cis is preferred for alkenyls such as 2-butenyl, 2-pentenyl, and 2-hexenyl.

[0072] Preferred alkenyloxy groups are vinyloxy, allyloxy, 3-butenyloxy, 3-pentenyloxy, and 4-pentenyloxy. To decrease the viscosity, more preferred alkenyloxy groups are allyloxy and 3-butenyloxy.

[0073] Preferred examples of alkyl in which at least one hydrogen is replaced by fluorine or chlorine include fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl, and 8-fluorooctyl. More preferred examples are 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, and 5-fluoropentyl for increasing the dielectric anisotropy.

[0074] Preferred examples of alkenyl in which at least one hydrogen is replaced by fluorine or chlorine include 2,2-difluorovinyl, 3,3-difluoro-2-propenyl, 4,4-difluoro-3-butenyl, 5,5-difluoro-4-pentenyl, and 6,6-difluoro-5-hexenyl. More preferred examples are 2,2-difluorovinyl and 4,4-difluoro-3-butenyl to reduce viscosity.

[0075] Ring A 1 is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl. 1 is 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,6-difluoro-1,4-phenylene for increasing the optical anisotropy or for increasing the dielectric anisotropy. 2is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl. 2 is 1,4-cyclohexylene to increase the maximum temperature, 1,4-phenylene to increase the optical anisotropy, and 2-fluoro-1,4-phenylene or 2,6-difluoro-1,4-phenylene to increase the dielectric anisotropy. 3 and ring D 3 is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene. 3 or ring D 3 is 1,4-cyclohexylene for decreasing the viscosity or increasing the maximum temperature, and is 1,4-phenylene or 2-fluoro-1,4-phenylene for increasing the optical anisotropy or decreasing the minimum temperature.

[0076] Ring A 1 and ring C 2 In the formula, tetrahydropyran-2,5-diyl is [ka] or [ka] and preferably [ka] is.

[0077] Z 11 is a single bond, carbonyloxy, or difluoromethyleneoxy. 11 is a single bond to decrease the viscosity, and is carbonyloxy or difluoromethyleneoxy to increase the dielectric anisotropy. 21is a single bond, ethylene, vinylene, carbonyloxy, or difluoromethyleneoxy. 21 is a single bond to decrease the viscosity, and is difluoromethyleneoxy to increase the dielectric anisotropy. 31 is a single bond, ethylene, vinylene, ethynylene, methyleneoxy, or carbonyloxy. 31 is a single bond to reduce viscosity.

[0078] X 11 and X 12 is hydrogen or fluorine. 11 or X 12 is hydrogen to decrease the viscosity, and is fluorine to increase the dielectric anisotropy. 21 and X 22 is hydrogen or fluorine. 21 or X 22 is fluorine to increase the dielectric anisotropy.

[0079] Y 21 is fluorine, chlorine, alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, alkoxy having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or alkenyloxy having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine. 21 is fluorine, alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or alkoxy having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine in order to increase the dielectric anisotropy.

[0080] A preferred example of alkyl in which at least one hydrogen is replaced by fluorine or chlorine is trifluoromethyl. A preferred example of alkoxy in which at least one hydrogen is replaced by fluorine or chlorine is trifluoromethoxy.

[0081] n1 is 1 or 2. Desirable n1 is 1 for decreasing the viscosity, and 2 for increasing the maximum temperature or the optical anisotropy. n2 is 1, 2, 3, or 4. Desirable n2 is 1 or 2 for decreasing the viscosity, and 3 or 4 for increasing the dielectric anisotropy. n3 is 1, 2, or 3. Desirable n3 is 1 for decreasing the viscosity, and 2 or 3 for increasing the maximum temperature or the optical anisotropy.

[0082] Fifth, preferred additives and component compounds are shown. The first additive is at least one selected from the group consisting of compound (Ch1) and compound (Ch2), and is preferably compound (Ch1). At least one of the first additives is preferably compound (Ch1-2), compound (Ch1-3), or compound (Ch1-4). The most preferred optically active compound is (Ch1-4). In this case, R 1 and R 2 is preferably alkyl having 1 to 10 carbon atoms.

[0083] Preferred compounds as the second additive are compounds (M1-1) to (M1-5). In compounds (M1-1) to (M1-5), R a , R b , Y, Z M is R in compound (M1) a , R b , Y, Z M In the compounds (M1-1) to (M1-5), X M1is preferably a halogen, an alkyl having 1 to 5 carbon atoms, a polymerizable group represented by any one of formulas (P-1) to (P-6), or an alkyl having 1 to 5 carbon atoms substituted with a polymerizable group represented by any one of formulas (P-1) to (P-6), and is preferably fluorine, methyl, or a polymerizable group represented by any one of formulas (P-1) to (P-6). f is preferably 0, 1, or 2, and more preferably 0 or 1. g is preferably 0, 1, or 2, and more preferably 0 or 1. h is preferably 0 or 1. In compounds (M1-1) to (M1-5), X M1 The total number is preferably 0 to 3, more preferably 0 to 2, and even more preferably 0 to 1. As the second additive, the compounds (M1-1) to (M1-3) are preferred, the compound (M1-1) or the compound (M1-2) is preferred, and the compound (M1-1) is particularly preferred.

[0084] Preferred examples of the compound (M1) include compounds represented by any of the following formulae: a , R b , Y, X M1 is R in formulas (M1-1) to (M1-5). a , R b , Y, X M1 and the preferred ranges are also the same. [ka]

[0085] [ka]

[0086] [ka]

[0087] Preferred compounds for the first component are compounds (1-1) to (1-9). Of these compounds, at least one is preferably compound (1-3), compound (1-7), or compound (1-8). More preferably, it is compound (1-3).

[0088] Preferred compounds for the second component are those represented by formulas (2-1) to (2-38). Of these compounds, at least one is preferably compound (2-9), compound (2-15), compound (2-19), compound (2-20), compound (2-30), compound (2-31), or compound (2-37). More preferably, it is compound (2-30) or compound (2-31).

[0089] Preferred compounds for the third component are compounds (3-1) to (3-20). Of these compounds, at least one is preferably compound (3-1), compound (3-2), compound (3-9), compound (3-10), compound (3-15), compound (3-16), compound (3-17), compound (3-19), or compound (3-20).

[0090] Sixth, additives that may be added to the composition are described below. Such additives include a polymerization initiator, an optically active compound other than the compound (Ch1) and the compound (Ch2), an antioxidant, an ultraviolet absorber, a dye, an antifoaming agent, a polymerizable compound other than the compound (M1), a polymerization inhibitor, a polar compound, etc.

[0091] When a polymerization initiator is added to the composition, a photoradical polymerization initiator, a thermal radical polymerization initiator, a photocationic polymerization initiator, or the like may be appropriately selected depending on the polymerizable group possessed by the compound (M1) or other polymerizable compounds.

[0092] Examples of the photoradical polymerization initiator include DAROCUR 1173 and 4265 (all trade names, BASF Japan Ltd.), IRGACURE 184, 369, 500, 651, 784, 819, 907, 1300, 1700, 1800, 1850, and 2959 (all trade names, BASF Japan Ltd.), and the like.

[0093] Examples of preferred initiators for radical polymerization include benzoyl peroxide, diisopropyl peroxydicarbonate, t-butylperoxy-2-ethylhexanoate, t-butylperoxypivalate, t-butylperoxydiisobutyrate, lauroyl peroxide, dimethyl 2,2′-azobisisobutyrate (MAIB), di-t-butyl peroxide (DTBPO), azobisisobutyronitrile (AIBN), and azobiscyclohexanecarbonitrile (ACN).

[0094] Examples of the photocationic polymerization initiator include diaryliodonium salts (hereinafter referred to as "DAS") and triarylsulfonium salts (hereinafter referred to as "TAS").

[0095] Examples of DAS include diphenyliodonium tetrafluoroborate, diphenyliodonium hexafluorophosphonate, diphenyliodonium hexafluoroarsenate, diphenyliodonium trifluoromethanesulfonate, diphenyliodonium trifluoroacetate, diphenyliodonium-p-toluenesulfonate, diphenyliodonium tetra(pentafluorophenyl)borate, 4-methoxyphenylphenyliodonium tetrafluoroborate, 4-methoxyphenylphenyliodonium hexafluorophosphonate, 4-methoxyphenylphenyliodonium hexafluoroarsenate, 4-methoxyphenylphenyliodonium trifluoromethanesulfonate, 4-methoxyphenylphenyliodonium trifluoroacetate, and 4-methoxyphenylphenyliodonium-p-toluenesulfonate.

[0096] The sensitivity of DAS can be increased by adding a photosensitizer such as thioxanthone, phenothiazine, chlorothioxanthone, xanthone, anthracene, diphenylanthracene, or rubrene.

[0097] Examples of TAS include triphenylsulfonium tetrafluoroborate, triphenylsulfonium hexafluorophosphonate, triphenylsulfonium hexafluoroarsenate, triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium trifluoroacetate, triphenylsulfonium-p-toluenesulfonate, triphenylsulfonium tetra(pentafluorophenyl)borate, 4-methoxyphenyldiphenylsulfonium tetrafluoroborate, 4-methoxyphenyldiphenylsulfonium hexafluorophosphonate, 4-methoxyphenyldiphenylsulfonium hexafluoroarsenate, 4-methoxyphenyldiphenylsulfonium trifluoromethanesulfonate, 4-methoxyphenyldiphenylsulfonium trifluoroacetate, and 4-methoxyphenyldiphenylsulfonium-p-toluenesulfonate.

[0098] Specific examples of trade names of cationic photopolymerization initiators include Cyracure UVI-6990, Cyracure UVI-6974, and Cyracure UVI-6992 (each trade name, UCC Corporation), Adeka Optomer SP-150, SP-152, SP-170, and SP-172 (each trade name, ADEKA Corporation), Rhodorsil Photoinitiator 2074 (trade name, Rhodia Japan Co., Ltd.), IRGACURE 250 (trade name, BASF Japan Co., Ltd.), and UV-9380C (trade name, GE Toshiba Silicones Co., Ltd.).

[0099] From the viewpoint of obtaining a higher contrast, the amount of the polymerization initiator added is preferably 0.1% by mass or less, more preferably 0.05% by mass or less, further preferably 0.03% by mass or less, and particularly preferably 0.01% by mass or less, based on the host liquid crystal composition. The cholesteric liquid crystal composition of the present invention may not contain a polymerization initiator.

[0100] Examples of optically active compounds other than Compound (Ch1) and Compound (Ch2) include Compound (5-1) to Compound (5-5). The preferred ratio of optically active compounds other than Compound (Ch1) and Compound (Ch2) is about 5% by mass or less relative to the host liquid crystal composition. A more preferred ratio is in the range of about 0.0% by mass to about 2.0% by mass. The cholesteric liquid crystal composition of the present invention has suitable properties even without the addition of optically active compounds other than Compound (Ch1) and Compound (Ch2).

[0101] [ka]

[0102] Examples of polymerizable compounds other than compound (M1) include compounds other than compound (M1) that have a polymerizable group represented by formulas (P-1) to (P-6). These compounds may or may not have a mesogenic moiety. For specific examples of polymerizable compounds other than compound (M1), see paragraphs

[0141] to

[0159] of JP 2019-214698 A. The total content of polymerizable compounds (including compound (M1)) in the cholesteric liquid crystal composition of the present invention is preferably less than 2.0% by mass relative to the host liquid crystal composition. It is also preferably 0.1% by mass or more. The cholesteric liquid crystal composition of the present invention exhibits suitable properties even without the addition of polymerizable compounds other than compound (M1).

[0103] In order to prevent a decrease in resistivity due to heating in the atmosphere, or to maintain a large voltage holding ratio not only at room temperature but also at temperatures close to the upper limit temperature after long-term use of the element, an antioxidant such as compounds (6-1) to (6-3) may be further added to the composition.

[0104] [ka]

[0105] Because compound (6-2) has low volatility, it is effective in maintaining a high voltage holding ratio not only at room temperature but also at temperatures close to the upper limit temperature after long-term use of the device. The preferred antioxidant content is about 50 ppm or more to achieve this effect, and about 600 ppm or less to avoid lowering the upper limit temperature or raising the lower limit temperature. A more preferred content is in the range of about 100 ppm to about 300 ppm.

[0106] Preferred examples of ultraviolet absorbers include benzophenone derivatives, benzoate derivatives, and triazole derivatives. Light stabilizers such as sterically hindered amines are also preferred. Preferred examples of light stabilizers include compounds (7-1) to (7-16). The preferred ratio of these absorbers and stabilizers is about 50 ppm or more to obtain their effects, and about 10,000 ppm or less to avoid lowering the maximum temperature or raising the minimum temperature. A more preferred ratio is in the range of about 100 ppm to about 10,000 ppm.

[0107] [ka]

[0108] [ka]

[0109] A quencher is a compound that receives light energy absorbed by a liquid crystal compound and converts it into thermal energy, thereby preventing decomposition of the liquid crystal compound. Preferred examples of the quencher include compounds (8-1) to (8-7). The preferred proportion of these quenchers is about 50 ppm or more to obtain the desired effect, and about 20,000 ppm or less to avoid increasing the minimum temperature. A more preferred proportion is in the range of about 100 ppm to about 10,000 ppm.

[0110] [ka]

[0111] Seventh, the synthesis methods of the additives and component compounds will be described. These compounds can be obtained from Sigma-Aldrich Corporation or synthesized by known methods. Compound (M1-1) can be synthesized by the method described in International Publication No. 2015-4947. Compound (Ch1-4) can be synthesized by the method described in International Publication No. 2014-97952. Compound (1-7) can be synthesized by the method described in Japanese Patent Application Laid-Open No. 10-114733. Compound (2-19) can be synthesized by the method described in Japanese Patent Application Laid-Open No. 10-251186. Compound (3-1) can be synthesized by the method described in Japanese Patent Application Laid-Open No. 9-77692.

[0112] Compounds for which no synthetic method is described can be synthesized by methods described in textbooks such as Organic Syntheses (John Wiley & Sons, Inc.), Organic Reactions (John Wiley & Sons, Inc.), Comprehensive Organic Synthesis (Pergamon Press), and New Experimental Chemistry Lectures (Maruzen). Compositions can be prepared from the compounds thus obtained by known methods. For example, the component compounds can be mixed and dissolved by heating.

[0113] Finally, the use of the composition will be described. The composition of the present invention can be used as a cholesteric liquid crystal composition having a selective reflection wavelength in the range of 350 to 800 nm by including the optically active compound, compound (Ch1) or compound (Ch2). The composition of the present invention can have the above-mentioned suitable properties by adjusting the ratio of the component compounds or by mixing other liquid crystal compounds, as necessary, and is suitable for liquid crystal devices, particularly reflective liquid crystal devices. [Example]

[0114] The present invention will be further described in detail by way of examples, but is not limited to these examples. The present invention also includes mixtures of at least two of the compositions of the examples, such as a mixture of the composition of Example 1 and the composition of Example 13.

[0115] Measurement methods: The characteristics were measured using the following methods. Most of these methods are based on or modified from the JEITA standard (JEITA ED-2521B) established by the Japan Electronics and Information Technology Industries Association (JEITA). The twisted nematic (TN) elements used for the measurements were not equipped with thin film transistors (TFTs).

[0116] (1) The maximum temperature of the nematic phase (NI; °C), the maximum temperature of the cholesteric phase (N * I): A sample was placed on the hot plate of a melting point measurement apparatus equipped with a polarizing microscope and heated at a rate of 1°C / min. The temperature at which a part of the sample changed from the nematic or cholesteric phase to an isotropic liquid was measured. The upper limit temperature of the nematic or cholesteric phase is sometimes abbreviated as the "maximum temperature."

[0117] (2) The lowest temperature (T C; °C): Samples with a nematic or cholesteric phase were placed in glass bottles and stored in freezers at 0 °C, -10 °C, -20 °C, -30 °C, and -40 °C for 10 days, after which the liquid crystal phase was observed. For example, when a sample remained in a nematic or cholesteric phase at -20 °C and changed to a crystalline or smectic phase at -30 °C, T C When the phase changes to a crystalline or smectic phase at 0°C or 25°C (room temperature), T C are expressed as >0°C and >25°C, respectively. The lower limit temperature of the nematic phase or the cholesteric phase is sometimes abbreviated as "lower limit temperature."

[0118] (3) Viscosity (bulk viscosity; η; measured at 25°C; mPa·s): Measurement was performed using an E-type rotational viscometer manufactured by Tokyo Keiki Co., Ltd.

[0119] (4) Viscosity (rotational viscosity; γ1; measured at 25°C; mPa·s): Measurement was performed according to the method described in M. Imai et al., Molecular Crystals and Liquid Crystals, Vol. 259, 37 (1995). A sample was placed in a TN device with a twist angle of 0° and a cell gap of 5 μm between the two glass substrates. A voltage was applied to this device in 0.5 V increments ranging from 16 V to 19.5 V. After a 0.2-second period without voltage application, a single square wave (rectangular pulse; 0.2 seconds) followed by no voltage application (2 seconds) was applied repeatedly. The peak current and peak time of the transient current generated by this voltage application were measured. The rotational viscosity was calculated from these measurements and equation (10) on page 40 of the paper by M. Imai et al. The value of the dielectric anisotropy required for this calculation was determined by the method described below using the device used to measure the rotational viscosity.

[0120] (5) Optical anisotropy (refractive index anisotropy; Δn; measured at 25°C): Measurements were made using light with a wavelength of 589 nm and an Abbe refractometer equipped with a polarizing plate attached to an eyepiece. After rubbing the surface of the main prism in one direction, a sample was dropped onto the main prism. The refractive index n∥ was measured when the direction of polarized light was parallel to the rubbing direction. The refractive index n⊥ was measured when the direction of polarized light was perpendicular to the rubbing direction. The optical anisotropy value was calculated from the formula Δn=n∥-n⊥.

[0121] (6) Dielectric anisotropy (Δε; measured at 25°C): A sample was placed in a TN device with a cell gap of 9 μm between two glass substrates and a twist angle of 80°. A sine wave (10 V, 1 kHz) was applied to the device, and the dielectric constant (ε∥) in the long axis direction of the liquid crystal molecules was measured after 2 seconds. A sine wave (0.1 V, 1 kHz) was applied to the device, and the dielectric constant (ε⊥) in the short axis direction of the liquid crystal molecules was measured after 2 seconds. The dielectric anisotropy value was calculated using the formula Δε = ε∥ - ε⊥.

[0122] (7-1) Threshold voltage (Vth(25); measured at 25°C; V): Measurement was performed using an LCD5200 luminance meter manufactured by Otsuka Electronics Co., Ltd. A halogen lamp was used as the light source. A sample was placed in an FFS element with a cell gap of 3.2 μm between the two glass substrates. The voltage (32 Hz, square wave) applied to this element was increased in steps of 0.01 V from 0 V to 10 V. During this time, light was irradiated perpendicularly onto the element, and the amount of light transmitted through the element was measured. A voltage-transmittance curve was created in which the maximum amount of light represented 100% transmittance and the minimum amount of light represented 0% transmittance. The threshold voltage was expressed as the voltage at which the transmittance reached 95%.

[0123] (7-2) Threshold voltage (Vth(-30); measured at -30°C; V): Same as (7-1) except that it was measured at -30°C.

[0124] (8) Voltage holding ratio (VHR-1; measured at 25°C; %): The TN element used for the measurement had a polyimide alignment film, and the distance between the two glass substrates (cell gap) was 5 μm. After the sample was placed in the element by vacuum injection, the injection port was sealed with an ultraviolet-curing adhesive. A pulse voltage (1 V for 60 microseconds) was applied to the TN element to charge it. The decaying voltage was measured for 166.7 milliseconds with a high-speed voltmeter, and the area A between the voltage curve and the horizontal axis in a unit period was calculated. Area B was the area when there was no decay. The voltage holding ratio was expressed as the percentage of area A to area B.

[0125] (9) Voltage holding ratio (VHR-2; measured at 60°C; %): The voltage holding ratio was measured in the same manner as above, except that the measurement was performed at 60°C instead of 25°C. The obtained value was expressed as VHR-2.

[0126] (10) Voltage holding ratio (VHR-3; measured at 60°C; %): After ultraviolet irradiation, the voltage holding ratio was measured to evaluate the stability against ultraviolet rays. The TN element used for the measurement had a polyimide alignment film and a cell gap of 5 μm. A sample was injected into this element, and the irradiated light was 5 mW / cm. 2 The element was irradiated with ultraviolet light of 167 minutes. The light source was a black light F40T10 / BL (peak wavelength 369 nm) manufactured by iGraphics Co., Ltd., and the distance between the element and the light source was 5 mm. In measuring VHR-3, the decaying voltage was measured over a period of 166.7 milliseconds. Compositions with a large VHR-3 have high stability against ultraviolet light.

[0127] (11) Voltage holding ratio (VHR-4; measured at 60°C; %): After the TN element into which the sample was injected was heated in a thermostatic chamber at 120°C for 20 hours, the voltage holding ratio was measured to evaluate the thermal stability. In the VHR-4 measurement, the voltage decay time was measured as 166.7 milliseconds. A composition with a large VHR-4 has high thermal stability.

[0128] (12) Voltage holding ratio (VHR-5; measured at 60°C; %): After the TN device into which the sample was injected was left standing under a backlight for two weeks, the voltage holding ratio was measured to evaluate the stability against the backlight. In the VHR-5 measurement, the voltage decay time was measured as 166.7 milliseconds. A composition with a large VHR-5 has high stability against the backlight.

[0129] (13) Response time (τ; measured at 25°C; ms): Measurements were performed using an LCD5200 luminance meter manufactured by Otsuka Electronics Co., Ltd. The light source was a halogen lamp. The low-pass filter was set to 5 kHz. The sample was placed in a TN device with a cell gap of 5 μm between two glass substrates. A square wave (60 Hz, Vth(25), 0.5 s) was applied to the device. Light was irradiated perpendicularly to the device, and the amount of light reflected from the device was measured. The maximum amount of light was considered to be 100% reflectance, and the minimum amount of light was considered to be 0% reflectance. The rise time (τr; rise time; ms) was the time required for the reflectance to change from 90% to 10%. The fall time (τf; ms) was the time required for the reflectance to change from 10% to 90%. The response time was expressed as the sum of the rise time and fall time. A voltage is applied to the element into which the sample has been injected in increments of 1 V from 0 V to 40 V, and the voltage at which the element switches from the initial reflective state to the transmissive state is defined as Vreset (V).

[0130] (14) Elastic constant (K; measured at 25°C; pN): Measurements were performed using a Yokogawa-Hewlett-Packard HP4284A LCR meter. A sample was placed in a horizontally aligned device with a cell gap of 20 μm between the two glass substrates. A charge of 0 to 20 volts was applied to the device, and the capacitance and applied voltage were measured. The measured capacitance (C) and applied voltage (V) were fitted using equations (2.98) and (2.101) on page 75 of the "Liquid Crystal Device Handbook" (Nikkan Kogyo Shimbun, Ltd.), and the values ​​of K11 and K33 were obtained from equation (2.99). Next, K22 was calculated using equation (3.18) on page 171 of the same publication, using the previously determined values ​​of K11 and K33. The elastic constant was expressed as the average of the values ​​of K11, K22, and K33 thus determined.

[0131] (15) Resistivity (ρ; measured at 25°C; Ωcm): 1.0 mL of sample was poured into a container equipped with electrodes. A DC voltage (10 V) was applied to the container, and the DC current was measured after 10 seconds. The resistivity was calculated using the following formula: (resistivity) = {(voltage) × (capacity of container)} / {(DC current) × (dielectric constant of vacuum)}.

[0132] (16) Helical pitch (P; measured at room temperature; μm): The helical pitch was measured by the wedge method. See page 196 of "Liquid Crystal Handbook" (published by Maruzen in 2000). The sample was poured into a wedge-shaped cell and allowed to stand at room temperature for two hours. The distance between the disclination lines (d2 - d1) was then observed using a polarizing microscope (Nikon Corporation, MM40 / 60 series). The helical pitch (P) was calculated using the following formula, where θ is the angle of the wedge cell: P = 2 × (d2 - d1) × tan θ.

[0133] (17) Dielectric constant in the minor axis direction (ε⊥; measured at 25°C): A sample was placed in a TN device with a cell gap of 9 μm between two glass substrates and a twist angle of 80°. A sine wave (0.1 V, 1 kHz) was applied to the device, and the dielectric constant in the minor axis direction (ε⊥) of the liquid crystal molecules was measured after 2 seconds.

[0134] (18) Frequency dependence of dielectric anisotropy (F10; measured at -20°C): A sample was placed in a TN device with a cell gap of 9 μm between two glass substrates and a twist angle of 80°. Sine waves (0.5 V, 20 Hz, 50 Hz, 100 Hz, 1 kHz, 5 kHz, 10 kHz, 50 kHz, 100 kHz, 500 kHz, and 1000 kHz) were applied to the device, and the dielectric constant (ε⊥) in the minor axis direction of the liquid crystal molecules was measured after 2 seconds. F10 was defined as the frequency at which the dielectric anisotropy decreased by 10% compared to the dielectric anisotropy at 20 Hz. A larger F10 indicates smaller frequency dependence.

[0135] (19) Selective reflection wavelength (λ; nm) and reflectance (%): Measurements were performed using a JASCO V-700 UV-Vis-NIR spectrophotometer equipped with an ISV-922 integrating sphere unit. The sample was placed in a device with a 5 μm cell gap between two glass substrates, and the reflected wavelength was measured at a 5° incident angle. A voltage of 40 V was applied to the device, and then the reflectance at each wavelength was measured when the voltage was returned to 0 V. The wavelength showing the maximum reflectance was defined as the selective reflection wavelength (40 V), and the reflectance at the selective reflection wavelength (40 V) was defined as the maximum reflectance (reflectance max). A voltage of 20 V was applied to the device, and then the voltage was returned to 0 V. The reflectance at each wavelength was measured when the voltage was returned to 0 V, and the reflectance at the selective reflection wavelength (40 V) was defined as the minimum reflectance (reflectance min). Contrast (CR) was calculated using the following formula: CR = reflectance max / reflectance min.

[0136] (20) The temperature change of the selective reflection wavelength was measured as a difference (nm) from 25 to 60 °C.

[0137] Examples of the cholesteric liquid crystal composition of the present invention are shown below. In the following, liquid crystal compounds are represented by symbols based on the definitions in Table 2 below. In Table 2, the configuration of 1,4-cyclohexylene is trans. The number in parentheses after the symbolized compound indicates the chemical formula to which the compound belongs. The symbol (-) means other liquid crystal compounds. The proportion (percentage) of the liquid crystal compound is a mass percentage (mass %) based on the mass of the host nematic liquid crystal composition containing no additives.

[0138] [Table 2]

[0139] [Examples 1 to 6 and Comparative Examples 1 to 7] Cholesteric liquid crystal compositions of Examples 1 to 6 and Comparative Examples 1 to 7 were prepared by adding an optically active compound, a polymerizable compound, and other additives to host liquid crystal composition A in the proportions shown in Table 3 relative to the mass of host liquid crystal composition A, and the properties were evaluated. The results are shown in Table 3. In Table 3, the entries marked "(host liquid crystal composition)" indicate the evaluation results for host liquid crystal composition A.

[0140] (Host Liquid Crystal Composition A) 1V2-BEB(F,F)-C (1-3) 9% 2-BEB(F)-C (1-3) 8% 5-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 11% 3-HH-V (3-1) 12% 3-HB-O2 (3-2) 6% 1-BB(F)B-2V (3-10) 7% 2-BB(F)B-2V (3-10) 7% 5-HBB(F)B-2 (3-15) 7% 5-HBB(F)B-3 (3-15) 7% 3-HB(F)TB-2 (3-19) 6% 3-HB(F)TB-3 (3-19) 6% 3-HB(F)TB-4 (3-19) 6%

[0141] In Tables 3 and 4, blank spaces for additives or additives indicate that no additives were added, and blank spaces for evaluation indicate that no evaluation (measurement) was made. The components in Tables 3 and 4 are as follows:

[0142] [ka]

[0143] [Table 3]

[0144] The results shown in Table 3 indicate that high contrast (CR≧2.00) was obtained by using compound (M1) in an amount of less than 2% by mass relative to the host liquid crystal composition. In addition, in the case where an optically active compound other than compound (Ch1) or compound (Ch2) was used, the change in reflection wavelength was large and the contrast was low.

[0145] [Examples 7 to 13 and Comparative Example 8] Compound (Ch1-1-1) and compound (M1-1-1) were added to each of the following host liquid crystal compositions in the proportions shown in Table 4 relative to each host liquid crystal composition to prepare cholesteric liquid crystal compositions of Examples 7 to 13 and Comparative Example 8, and the properties were evaluated. The results are shown in Table 4. In Table 4, the entries marked "(host liquid crystal composition)" indicate the evaluation results for each host liquid crystal composition.

[0146] (Host Liquid Crystal Composition: Comparative Example 8) 3-HBB(F,F)-F (2-9) 12% 3-GB(F,F)XB(F,F)-F (2-15) 10% 3-BB(F,F)XB(F,F)-F (2-19) 10% 2-HHBB(F,F)-F (2-20) 4% 5-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 18% 5-HBB(F)B-2 (3-15) 12% 5-HBB(F)B-3 (3-15) 11% 2-BB(2F,5F)B-2 (3-16) 6% 3-BB(2F,5F)B-3 (3-16) 9%

[0147] (Host Liquid Crystal Composition: Example 7) 1V2-BEB(F,F)-C (1-3) 8% 3-HBB(F,F)-F (2-9) 10% 2-HHBB(F,F)-F (2-20) 4% 5-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 18% 3-HH-V (3-1) 14% 5-HBB(F)B-2 (3-15) 12% 5-HBB(F)B-3 (3-15) 11% 2-BB(2F,5F)B-2 (3-16) 6% 3-BB(2F,5F)B-3 (3-16) 9%

[0148] (Host Liquid Crystal Composition: Example 8) 1V2-BEB(F,F)-C (1-3) 9% 2-BEB(F)-C (1-3) 8% 5-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 11% 3-HH-V (3-1) 12% 3-HB-O2 (3-2) 6% 1-BB(F)B-2V (3-10) 7% 2-BB(F)B-2V (3-10) 7% 5-HBB(F)B-2 (3-15) 7% 5-HBB(F)B-3 (3-15) 7% 3-BB(F)TB-2 (3-20) 6% 3-BB(F)TB-3 (3-20) 6% 3-BB(F)TB-4 (3-20) 6%

[0149] (Host Liquid Crystal Composition: Example 9) 5-BEB(F,F)-C (1-3) 9% 2-BEB(F)-C (1-3) 8% 5-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 11% 3-HH-V (3-1) 12% 3-HB-O2 (3-2) 6% 1-BB(F)B-2V (3-10) 7% 2-BB(F)B-2V (3-10) 7% 5-HBB(F)B-2 (3-15) 7% 5-HBB(F)B-3 (3-15) 7% 3-HB(F)TB-2 (3-19) 6% 3-HB(F)TB-3 (3-19) 6% 3-HB(F)TB-4 (3-19) 6%

[0150] (Host Liquid Crystal Composition: Example 10) 3-BEB(F,F)-C (1-3) 9% 2-BEB(F)-C (1-3) 8% 5-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 11% 3-HH-V (3-1) 12% 3-HB-O2 (3-2) 6% 1-BB(F)B-2V (3-10) 7% 2-BB(F)B-2V (3-10) 7% 5-HBB(F)B-2 (3-15) 7% 5-HBB(F)B-3 (3-15) 7% 3-HB(F)TB-2 (3-19) 6% 3-HB(F)TB-3 (3-19) 6% 3-HB(F)TB-4 (3-19) 6%

[0151] (Host Liquid Crystal Composition: Example 11) 1V2-BEB(F,F)-C (1-3) 9% 2-BEB(F)-C (1-3) 8% 5-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 4% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 11% 3-HH-V (3-1) 12% 3-HB-O2 (3-2) 6% 1-BB(F)B-2V (3-10) 7% 2-BB(F)B-2V (3-10) 7% 5-HBB(F)B-2 (3-15) 7% 5-HBB(F)B-3 (3-15) 7% 3-BTB-O1 (3-17) 6% 3-HB(F)TB-3 (3-19) 6% 3-HB(F)TB-4 (3-19) 6%

[0152] (Host Liquid Crystal Composition: Example 12) 1V2-BEB(F,F)-C (1-3) 17% 2-BEB(F)-C (1-3) 4% 3-BB(F)BC (1-8) 5% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 5% 3-BB(F)B(F,F)XB(F,F)-F (2-30) 5% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 10% 3-HH-V (3-1) 5% 1-BB(F)B-2V (3-10) 7% 2-BB(F)B-2V (3-10) 8% 5-HBB(F)B-2 (3-15) 5% 5-HBB(F)B-3 (3-15) 4% 3-BTB-O1 (3-17) 10% 3-HB(F)TB-2 (3-19) 5% 3-HB(F)TB-3 (3-19) 5% 3-HB(F)TB-4 (3-19) 5%

[0153] (Host Liquid Crystal Composition: Example 13) 1V2-BEB(F,F)-C (1-3) 17% 2-BEB(F)-C (1-3) 5% 4-BB(F)B(F,F)XB(F,F)-F (2-30) 8% 3-BB(F)B(F,F)XB(F,F)-F (2-30) 3% 3-BB(F,F)XB(F)B(F,F)-F (2-31) 15% 3-GB(F,F)XB(F)B(F,F)-F (2-37) 10% 3-HH-V (3-1) 7% 3-BTB-O1 (3-17) 10% 3-HB(F)TB-3 (3-19) 5% 3-HB(F)TB-4 (3-19) 5% 3-BB(F)TB-2 (3-20) 5% 3-BB(F)TB-3 (3-20) 5% 3-BB(F)TB-4 (3-20) 5%

[0154] [Table 4]

[0155] The results shown in Tables 3 and 4 indicate that the other examples containing compound (1) have lower viscosities than Comparative Example 8, which does not contain compound (1). It was also shown that various compositions containing compound (1), compound (2), compound (3), and compound (Ch1) or compound (Ch2) and compound (M1) can provide cholesteric liquid crystal compositions with high contrast and other excellent properties. [Industrial Applicability]

[0156] The cholesteric liquid crystal composition of the present invention makes it possible to produce a cholesteric liquid crystal device having high contrast and short response time.

Claims

1. A host liquid crystal composition comprising, as a first component, at least one compound selected from the compounds represented by formula (1), and, as a first additive, at least one optically active compound selected from the compounds represented by formula (Ch1) and formula (Ch2), and, as a second additive, at least one polymerizable compound selected from the compounds represented by formula (M1), A cholesteric liquid crystal composition, wherein the content of the second additive is less than 2.0% by weight based on the weight of the host liquid crystal composition. 【Chemistry 1】 In formula (1), R １１ is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms; １ is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, or tetrahydropyran-2,5-diyl; Z １１ is a single bond, carbonyloxy, or difluoromethyleneoxy; X １１ and X １２ is hydrogen or fluorine; n1 is 1 or 2; In formula (Ch1) and formula (Ch2), R １ , R ２ , and R ３ is hydrogen, halogen, cyano, -SF ５ or alkyl having 1 to 10 carbon atoms, in which at least one —CH ２ - may be replaced by -O-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups, at least one hydrogen may be replaced by fluorine or chlorine; ring A, ring B, ring E, and ring F are 5,6,7,8-tetrahydronaphthalene-1,2-diyl or naphthalene-1,2-diyl; ring C, ring D, and ring G are 1,4-cyclohexylene, 1,4-phenylene, 1,3-dioxane-2,5-diyl, tetrahydropyran-2,5-diyl, tetrahydropyran-3,5-diyl, pyrimidine-2,5-diyl, pyridine-2,5-diyl, or 1,4-bicyclo-(2,2,2)-octylene, and in these rings, at least one hydrogen may be replaced by fluorine or chlorine; Z １ , Z ２ , Z ３ , Z ４ , and Z ５ is a single bond or an alkylene having 1 to 20 carbon atoms, and in this alkylene, at least one —CH ２ - may be replaced by -O-, -CO-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups, at least one hydrogen may be replaced by fluorine or chlorine; a, b, and c are 2, 3, or 4; In formula (M1), R ａ and R ｂ represents a polymerizable group represented by any one of formulas (P-1) to (P-6), hydrogen, halogen, —C≡N, —N═C═O, or —N═C═S, and R ａ and R ｂ at least one of the groups is the polymerizable group; 【Chemistry 2】 In formulas (P-1) to (P-6), M １ From M ３ is hydrogen, fluorine, alkyl having 1 to 5 carbon atoms, or alkyl having 1 to 5 carbon atoms in which at least one hydrogen atom is replaced by fluorine; １ From M ３ In the formula, at least one —CH ２ - may be replaced by -O-; A Ｍ１ and A Ｍ２ is a divalent group obtained by removing two hydrogen atoms from a ring having aromaticity, and in these rings, at least one hydrogen atom is replaced by a halogen atom, an alkyl having 1 to 5 carbon atoms, a halogenated alkyl having 1 to 5 carbon atoms, or at least one —CH ２ - may be replaced by an alkyl having 1 to 5 carbon atoms in which - is replaced by -O- or -COO-, a polymerizable group represented by any one of formulas (P-1) to (P-6), an alkyl having 1 to 5 carbon atoms in which at least one hydrogen is replaced by a polymerizable group represented by any one of formulas (P-1) to (P-6), or a halogenated alkyl having 1 to 5 carbon atoms in which at least one hydrogen is replaced by a polymerizable group represented by any one of formulas (P-1) to (P-6); Y Ｍ１ and Y Ｍ２ is a single bond or an alkylene having 1 to 12 carbon atoms, and in this alkylene, at least one —CH ２ - may be replaced by -O- or -S-, and at least one -CH ２ -CH ２ - may be replaced by -CH=CH-, -C≡C-, -COO-, or -OCO-; Y Ｍ１ and Y Ｍ２ At least one of is a single bond or at least one -CH ２ - is alkylene having 1 to 4 carbon atoms which may be replaced by -O-; Z Ｍ is a single bond, -(CH ２ ) ｍ２ -, -O(CH ２ ) ｍ２ -, -(CH ２ ) ｍ２ O-, -O(CH ２ ) ｍ２ O-, -CH=CH-, -C≡C-, -COO-, -OCO-, -(CF ２ ) ２ -, -(CH ２ ) ２ -COO-, -OCO-(CH ２ ) ２ -, -CH=CH-COO-, -OCO-CH=CH-, -C≡C-COO-, -OCO-C≡C-, -CH=CH-(CH ２ ) ２ -, -(CH ２ ) ２ -CH=CH-, -CF=CF-, -C≡C-CH=CH-, -CH=CH-C≡C-, -OCF ２ - (CH ２ ) ２ -, -(CH ２ ) ２ -CF ２ O-, -OCF ２ - or -CF ２ O- (wherein m2 is 1 or 2); m1 is an integer from 1 to 5.

2. Formula (M1) contains two or three polymerizable groups represented by any one of formulas (P-1) to (P-6), and R ａ and R ｂ and each of the formulas (P-1) to (P-6) is a polymerizable group represented by any one of the formulas (P-1) to (P-6).

3. The cholesteric liquid crystal composition of claim 1 , wherein the total content of the polymerizable compounds is less than 2.0% by mass based on the mass of the host liquid crystal composition.

4. Y Ｍ１ and Y Ｍ２ is a single bond or an alkylene having 1 to 8 carbon atoms, and in this alkylene, at least one —CH ２ - may be replaced by -O-, -S-, and at least one -CH ２ -CH ２ - may be replaced by -CH=CH-, -C≡C-, -COO-, or -OCO-; Y Ｍ１ and Y Ｍ２ At least one of is a single bond or at least one -CH ２ 2. The cholesteric liquid crystal composition according to claim 1, wherein - is alkylene having 1 to 4 carbon atoms which may be replaced by -O-.

5. 2. The cholesteric liquid crystal composition according to claim 1, comprising at least one polymerizable compound selected from the compounds represented by formulae (M1-1) to (M1-5) as a second additive. 【Transformation 3】 In formulas (M1-1) to (M1-5), R ａ , R ｂ , Y, Z Ｍ is R in formula (M1). ａ , R ｂ , Y, Z Ｍ are synonymous with X Ｍ１ is a halogen, an alkyl having 1 to 5 carbon atoms, a halogenated alkyl having 1 to 5 carbon atoms, or at least one —CH ２ an alkyl having 1 to 5 carbon atoms in which - is replaced by -O- or -COO-, a polymerizable group represented by any one of formulas (P-1) to (P-6), an alkyl having 1 to 5 carbon atoms in which at least one hydrogen is replaced by a polymerizable group represented by any one of formulas (P-1) to (P-6), or a halogenated alkyl having 1 to 5 carbon atoms in which at least one hydrogen is replaced by a polymerizable group represented by any one of formulas (P-1) to (P-6), Ｍ２ is hydrogen or methyl; f is 0, 1, 2, 3, or 4; g is 0, 1, 2, or 3; and h is 0, 1, or 2.

6. 2. The cholesteric liquid crystal composition according to claim 1, wherein the content of the polymerization initiator is 0.1% by mass or less based on the mass of the host liquid crystal composition.

7. 7. The cholesteric liquid crystal composition according to claim 1, comprising, as a first additive, at least one optically active compound selected from the compounds represented by formulas (Ch1-1) to (Ch1-6) and formulas (Ch2-1) to (Ch2-3). 【Chemistry 4】 【Transformation 5】 In formulas (Ch1-1) to (Ch1-6) and formulas (Ch2-1) to (Ch2-3), R １ , R ２ , and R ３ is hydrogen, halogen, cyano, -SF ５ or alkyl having 1 to 10 carbon atoms, in which at least one —CH ２ - may be replaced by -O-, -COO-, -OCO-, -CH=CH-, or -C≡C-, and in these groups, at least one hydrogen may be replaced by fluorine or chlorine; ring A, ring B, ring E, and ring F are 5,6,7,8-tetrahydronaphthalene-1,2-diyl or naphthalene-1,2-diyl.

8. 7. The cholesteric liquid crystal composition according to claim 1, wherein the content of the first additive is in the range of 0.1% by weight to 10% by weight based on the weight of the host liquid crystal composition.

9. 7. The cholesteric liquid crystal composition according to claim 1, comprising, as a first component, at least one compound selected from the compounds represented by formulas (1-1) to (1-9): 【Transformation 6】 In formulas (1-1) to (1-9), R １１ is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms; X １１ and X １２ is hydrogen or fluorine.

10. 7. The cholesteric liquid crystal composition according to claim 1, wherein the content of the first component is in the range of 5% by mass to 30% by mass based on the mass of the host liquid crystal composition.

11. 7. The cholesteric liquid crystal composition according to claim 1, wherein the host liquid crystal composition further contains at least one compound selected from the compounds represented by formula (2) as a second component: 【Transformation 7】 In formula (2), R ２１ is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms; ２ is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,3-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; Z ２１ is a single bond, ethylene, vinylene, carbonyloxy, or difluoromethyleneoxy; X ２１ and X ２２ is hydrogen or fluorine; Y ２１ is fluorine, chlorine, alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, alkoxy having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine, or alkenyloxy having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine; and n2 is 1, 2, 3, or 4.

12. 12. The cholesteric liquid crystal composition according to claim 11, comprising, as a second component, at least one compound selected from the compounds represented by formulas (2-1) to (2-38): 【Transformation 8】 【Chemistry 9】 【Chemistry 10】 【Chemistry 11】 【Chemistry 12】 In formulas (2-1) to (2-38), R ２１ is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms.

13. 12. The cholesteric liquid crystal composition according to claim 11, wherein the content of the second component is in the range of 5% by weight to 50% by weight based on the weight of the host liquid crystal composition.

14. 7. The cholesteric liquid crystal composition according to claim 1, wherein the host liquid crystal composition further contains at least one compound selected from the compounds represented by formula (3) as a third component: 【Chemistry 13】 In formula (3), R ３１ and R ３２ is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine; ３ and Ring D ３ is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,5-difluoro-1,4-phenylene; Z ３１ is a single bond, ethylene, vinylene, ethynylene, methyleneoxy, or carbonyloxy; and n3 is 1, 2, or 3.

15. The cholesteric liquid crystal composition according to claim 14, further comprising at least one compound selected from the compounds represented by formulas (3-1) to (3-20) as a third component: 【Chemistry 14】 【Chemistry 15】 In formulas (3-1) to (3-20), R ３１ and R ３２ is alkyl having 1 to 12 carbon atoms, alkoxy having 1 to 12 carbon atoms, alkenyl having 2 to 12 carbon atoms, or alkenyl having 2 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine.

16. 15. The cholesteric liquid crystal composition according to claim 14, wherein the content of the third component is in the range of 10% by weight to 90% by weight based on the weight of the host liquid crystal composition.

17. 7. A cholesteric liquid crystal composition according to claim 1, wherein the host liquid crystal composition has an optical anisotropy (measured at 25°C) at a wavelength of 589 nm in the range of 0.10 to 0.40, and a dielectric anisotropy (measured at 25°C) at a frequency of 1 kHz in the range of 10 to 100.

18. 7. The cholesteric liquid crystal composition according to claim 1, wherein the selective reflection wavelength is in the range of 350 to 800 nm.

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