Liquid crystal composite and liquid crystal light-adjusting element

文档序号：1409248 发布日期：2020-03-06 浏览：41次中文

阅读说明：本技术 液晶复合体及液晶调光元件 (Liquid crystal composite and liquid crystal light-adjusting element ) 是由松田尚子松村良成田辺真裕美于 2018-07-18 设计创作，主要内容包括：本发明提供一种含有如下的液晶组合物且适于调光的液晶复合体、以及具有所述液晶复合体的液晶调光元件,所述液晶组合物满足上限温度高、下限温度低、粘度小、光学各向异性大、正介电各向异性大之类的特性的至少一种,或在这些特性的至少两种之间具有适当的平衡。一种液晶复合体,含有液晶组合物以及聚合体,所述液晶组合物包含具有大的正介电各向异性的特定化合物,所述液晶复合体可进而含有具有高的上限温度或低的下限温度的特定化合物或具有大的负介电各向异性的特定化合物。(The present invention provides a liquid crystal composite suitable for dimming, which contains a liquid crystal composition satisfying at least one of characteristics such as a high upper limit temperature, a low lower limit temperature, a low viscosity, a large optical anisotropy, and a large positive dielectric anisotropy, or having an appropriate balance between at least two of these characteristics, and a liquid crystal dimming element having the liquid crystal composite. A liquid crystal composite contains a liquid crystal composition containing a specific compound having a large positive dielectric anisotropy and a polymer, and may further contain a specific compound having a high upper limit temperature or a low lower limit temperature or a specific compound having a large negative dielectric anisotropy.)

1. A liquid crystal composite comprising a liquid crystal composition containing at least one compound selected from the compounds represented by the formula (1) as a first component, and a polymer,

in the formula (1), R¹Is alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, or alkenyl group having 2 to 12 carbon atoms; ring a 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; z¹Is a single bond, ethylene, carbonyloxy, or difluoromethyleneoxy; x¹And X²Independently hydrogen or fluorine; y is¹Is fluorine, chlorine, cyano, alkyl of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, alkoxy of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, or alkenyloxy of carbon number 2 to 12 with at least one hydrogen substituted by fluorine or chlorine; a is 1,2,3, or 4.

2. The liquid crystal composite according to claim 1, wherein the liquid crystal composition contains at least one compound selected from the group of compounds represented by formulae (1-1) to (1-47) as a first component,

in the formulae (1-1) to (1-47), R¹Is alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms or alkenyl group having 2 to 12 carbon atoms, X¹And X²Independently hydrogen or fluorine; y is¹Is fluorine, chlorine, cyano, alkyl of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, alkoxy of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, or alkenyloxy of carbon number 2 to 12 with at least one hydrogen substituted by fluorine or chlorine.

3. The liquid crystal composite according to claim 1 or 2, wherein the proportion of the first component is in the range of 5 to 90% by weight based on the weight of the liquid crystal composition.

4. The liquid crystal composite according to any one of claims 1 to 3, wherein the liquid crystal composition contains at least one compound selected from the group consisting of compounds represented by formula (2) as a second component,

in the formula (2), R²And R³Independently 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 or chlorine; ring B and ring C are independently 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene, or pyrimidine-2, 5-diyl; z²Is a single bond, ethylene, ethynylene, or carbonyloxy; b is 1,2, or 3.

5. The liquid crystal composite according to any one of claims 1 to 4, wherein the liquid crystal composition contains at least one compound selected from the group of compounds represented by formulae (2-1) to (2-23) as a second component,

in the formulae (2-1) to (2-23), R²And R³Independently 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 or chlorine.

6. The liquid crystal composite according to claim 4 or 5, wherein the proportion of the second component is in the range of 5 to 90% by weight based on the weight of the liquid crystal composition.

7. The liquid crystal composite according to any one of claims 1 to 6, wherein the liquid crystal composition contains at least one compound selected from the group consisting of compounds represented by formula (3) as a third component,

in the formula (3), R⁴And R⁵Independently 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 alkenyloxy group having 2 to 12 carbon atoms; ring D and ring F are independently 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene in which at least one hydrogen is substituted by fluorine or chlorine, naphthalene-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, chroman-2, 6-diyl, or chroman-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine; ring E is 2, 3-difluoro-1, 4-phenylene, 2-chloro-3-fluoro-1, 4-phenylene, 2, 3-difluoro-5-methyl-1, 4-phenylene, 3,4, 5-trifluoronaphthalene-2, 6-diyl, or 7, 8-difluorochroman-2, 6-diyl; z³And Z⁴Independently a single bond, ethylene, carbonyloxy, or methyleneoxy; c is 1,2 or 3, d is 0 or 1; the sum of c and d is 3 or less.

8. The liquid crystal composite according to any one of claims 1 to 7, wherein the liquid crystal composition contains at least one compound selected from the group of compounds represented by formulae (3-1) to (3-22) as a third component,

in the formulae (3-1) to (3-22), R⁴And R⁵Independently 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 alkenyloxy group having 2 to 12 carbon atoms.

9. The liquid crystal composite according to claim 7 or 8, wherein the proportion of the third component ranges from 3 to 25% by weight based on the weight of the liquid crystal composition.

10. The liquid crystal composite according to any one of claims 1 to 9, wherein the polymer is a polymer derived from a polymerizable compound containing at least one compound selected from the compounds represented by formula (4),

P¹-Z⁵-P²(4)

in the formula (4), Z⁵Is C1-20 alkylene, wherein at least one hydrogen may be substituted by C1-5 alkyl, fluorine, chlorine, or P³Substituted by at least one-CH₂May be substituted by-O-, -CO-, -COO-, -OCO-, -NH-, -N (R)⁶) -, -CH ═ CH-, or-C ≡ C-substituted, at least one-CH₂-may be substituted by a divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic saturated aliphatic compound, a carbocyclic or heterocyclic unsaturated aliphatic compound, or a carbocyclic or heterocyclic aromatic compound, in which the number of carbons is from 5 to 35 and at least one hydrogen may pass through R⁶Or P³Substituted, here, R⁶Is an alkyl group having 1 to 12 carbon atoms, in which at least one-CH group₂May be substituted by-O-, -CO-, -COO-, or-OCO-substitution; p¹、P²And P³Independently a polymerizable group.

11. The liquid crystal composite according to claim 10, wherein in formula (4), Z⁵Is C1-20 alkylene, wherein at least one hydrogen may be substituted by C1-5 alkyl, fluorine, chlorine, or P³Substituted by at least one-CH₂May be substituted by-O-, -CO-, -COO-, -OCO-, -NH-, -N (R)⁶) -, -CH ═ CH-, or-C ≡ C-substituted, at least one hydrogen may be substituted by R⁶Or P³Substituted, here, R⁶Is an alkyl group having 1 to 12 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-; p¹、P²And P³Independently a polymerizable group.

12. The liquid crystal complex according to claim 10 or 11, wherein in formula (4), P is¹、P²And P³Independently a group selected from the group of polymerizable groups represented by the formulae (P-1) to (P-6),

in the formulae (P-1) to (P-6), M¹、M²And M³Independently hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine.

13. The liquid crystal composite according to any one of claims 10 to 12, wherein in formula (4), P is¹、P²And P³Is an acryloyloxy group or a methacryloyloxy group.

14. The liquid crystal composite according to any one of claims 1 to 9, wherein the polymer is a polymer derived from a polymerizable compound containing at least one compound selected from the compounds represented by formula (5),

in the formula (5), M⁴And M⁵Independently hydrogen or methyl; z⁶Is alkylene group having 21 to 80 carbon atoms, in which at least one hydrogen may be substituted by alkyl group having 1 to 20 carbon atoms, fluorine, or chlorine, and at least one-CH₂May be substituted by-O-, -CO-, -COO-, -OCO-, -NH-, -N (R)⁶) -, -CH ═ CH-, or-C ≡ C-substituted where R is substituted⁶Is an alkyl group having 1 to 12 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

15. The liquid crystal composite according to any one of claims 1 to 9, wherein the polymer is a polymer derived from a polymerizable compound containing at least one compound selected from the compounds represented by formula (6),

in formula (6), M⁶Is hydrogen or methyl; z⁷Is a single bond or an alkylene group having 1 to 5 carbon atoms, in which alkylene group at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-; r⁷Is an alkyl group having 1 to 40 carbon atoms, in which at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-, at least one-CH₂May be substituted by a divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic saturated aliphatic compound, a carbocyclic or heterocyclic unsaturated aliphatic compound, or a carbocyclic or heterocyclic aromatic compound, in which the carbon number is from 5 to 35 and at least one hydrogen may be substituted by an alkyl group of carbon number 1 to 12, of which at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

16. The liquid crystal composite according to claim 15, wherein in formula (6), M is⁶Is hydrogen or methyl; z⁷Is a single bond or an alkylene group having 1 to 5 carbon atoms, in which alkylene group at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-; r⁷Is an alkyl group having 1 to 40 carbon atoms, in which at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

17. The liquid crystal composite according to any one of claims 1 to 9, wherein the polymer is a polymer derived from a polymerizable compound containing at least one compound selected from the group of compounds represented by formula (7), formula (8), and formula (9),

in the formulae (7), (8) and (9), ring G, ring I, ring J, ring K, ring L and ring M are independently 1, 4-cyclohexylene, 1, 4-phenylene, 1, 4-cyclohexenylene, pyridine-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, naphthalene-2, 6-diyl or fluorene-2, 7-diyl, and in these divalent groups, at least one hydrogen may be substituted with fluorine, chlorine, cyano, hydroxyl, formyl, trifluoroacetyl, difluoromethyl, trifluoromethyl, alkyl having 1 to 5 carbon atoms, alkoxy having 1 to 5 carbon atoms, alkoxycarbonyl having 2 to 5 carbon atoms or alkanoyl having 1 to 5 carbon atoms; z⁸、Z¹⁰、Z¹²、Z¹³And Z¹⁷Independently is a single bond, -O-, -COO-, -OCO-, or-OCOO-; z⁹、Z¹¹、Z¹⁴And Z¹⁶Independently a single bond, -OCH₂-、-CH₂O-、-COO-、-OCO-、-COS-、-SCO-、-OCOO-、-CONH-、-NHCO-、-CF₂O-、-OCF₂-、-CH₂CH₂-、-CF₂CF₂-、-CH＝CHCOO-、-OCOCH＝CH-、-CH₂CH₂COO-、-OCOCH₂CH₂-、-CH＝CH-、-N＝CH-、-CH＝N-、-N＝C(CH₃)-、-C(CH₃) -N-, -N-, or-C ≡ C-; z¹⁵Is a single bond, -O-or-COO-; y is²Is hydrogen, fluorine, chlorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl of carbon number 1 to 20, alkenyl of carbon number 2 to 20, alkoxy of carbon number 1 to 20, or alkoxycarbonyl of carbon number 2 to 20; f and h are integers from 1 to 4; k and m are independently integers from 0 to 3; the sum of k and m is 1 to 4; e. g, i, j, l, and n are independently integers from 0 to 20; m⁷To M¹²Independently hydrogen or methyl.

18. The liquid crystal composite according to any one of claims 1 to 17, wherein the proportion of the liquid crystal composition is in the range of 50 to 95% by weight and the proportion of the polymer is in the range of 5 to 50% by weight, based on the weight of the liquid crystal composite.

19. The liquid crystal composite according to any one of claims 1 to 18, wherein the precursor of the liquid crystal composite is a polymerizable composition containing a liquid crystal composition and a polymerizable compound, the polymerizable composition containing a photopolymerization initiator as an additive.

20. A liquid crystal light-modulating element, wherein the light-modulating layer is the liquid crystal composite according to any one of claims 1 to 19, and the light-modulating layer is sandwiched between a pair of transparent substrates, and the transparent substrates have transparent electrodes.

21. The liquid crystal dimming element according to claim 20, wherein the transparent substrate is a glass plate or an acrylic plate.

22. The liquid crystal dimming element according to claim 20, wherein the transparent substrate is a plastic film.

23. A dimming window using the liquid crystal dimming element as claimed in any one of claims 20 to 22.

24. A smart window using the liquid crystal dimming element of any one of claims 20 to 22.

25. Use of a liquid crystal composite according to one of claims 1 to 19 in a liquid crystal dimming element.

26. Use of a liquid crystal composite according to one of claims 1 to 19 in a liquid crystal dimming element in which the transparent substrate is a plastic film.

27. Use of a liquid crystal composite according to one of claims 1 to 19 in a light control window.

28. Use of a liquid crystal composite according to one of claims 1 to 19 in a smart window.

Technical Field

The present invention generally relates to a liquid crystal light adjusting device. More specifically, the present invention relates to a liquid crystal light control element having a liquid crystal composite in which a polymer and a liquid crystal composition are combined.

Background

A method of scattering light or the like is used for the liquid crystal light control element. Such an element is used in a building material such as a window glass or a partition of a room, a vehicle-mounted part, or the like. In these devices, a soft substrate such as a plastic film is used in addition to a hard substrate such as a glass substrate. In the liquid crystal composition sandwiched between these substrates, the arrangement of liquid crystal molecules is changed by adjusting the applied voltage. By this method, light transmitted through the liquid crystal composition can be controlled, and thus the liquid crystal light control element is widely used in a display, an optical shutter, a light control window (prior document 1), a smart window (prior document 2), and the like.

An example of the liquid crystal light control element is a polymer dispersed type of light scattering mode. The liquid crystal composition is dispersed in the polymer. The element has the following features. The element is easy to manufacture. Since the film thickness can be easily controlled over a large area, a device with a large screen can be manufactured. A polarizing plate is not required, and thus a vivid display can be achieved. The angle of view is wide due to light scattering. The element has such excellent properties and is expected to be used for a light control glass, a projection display, a large-area display, and the like.

Another example is a polymer network (polymer network) type liquid crystal dimming element. In elements of the type described, the liquid crystal composition is present in a three-dimensional network of polymers. The composition is continuous, an aspect that is different from the polymer dispersed type. The element of the type described also has the same characteristics as the element of the polymer dispersion type. There are also liquid crystal light control elements in which a polymer network type and a polymer dispersion type are mixed.

A liquid crystal composition having appropriate characteristics is used for the liquid crystal light control element. By improving the properties of the composition, elements with good properties can be obtained. The correlation between the properties of both is summarized in the following Table 1. The properties of the composition are further illustrated on an element basis. The temperature range of the nematic phase is associated with the temperature range in which the element can be used. The upper limit temperature of the nematic phase is preferably about 90 ℃ or higher, and the lower limit temperature of the nematic phase is preferably about-20 ℃ or lower. The viscosity of the composition correlates to the response time of the element. In order to control the transmittance of light, the response time is preferably short. Ideally shorter than 1 millisecond of response time. Therefore, it is preferable that the viscosity of the composition is small. Further, it is preferable that the viscosity at low temperature is low. The elastic constant of the composition is correlated to the response time of the element. In order to achieve a short response time in the element, it is more preferable that the elastic constant in the composition is large.

TABLE 1 characteristics of liquid crystal compositions and liquid crystal dimming elements

Numbering	Characteristics of liquid Crystal composition	Characteristics of liquid crystal light-adjusting element
			1	Wide temperature range of nematic phase	Wide temperature range
2	Low viscosity	Short response time
			3	Large optical anisotropy	High haze
4	Large positive or negative dielectric anisotropy	Low threshold voltage and low power consumption
			5	Has large specific resistance	High voltage holding ratio
6	Is stable to light and heat	Long service life
			7	Large elastic constant	Short response time

The optical anisotropy of the composition is correlated with the haze ratio of the liquid crystal dimming element. The haze ratio is a ratio of diffused light to total transmitted light. When light is blocked, the haze ratio is preferably high. It is preferable for a large haze ratio that the optical anisotropy is large. The large dielectric anisotropy of the composition contributes to low threshold voltage or low power consumption in the device. Therefore, it is preferable that the dielectric anisotropy is large. The large specific resistance of the composition contributes to a large voltage holding ratio in the device. Therefore, a composition having a large specific resistance in the initial stage is preferable. A composition having a large specific resistance after a long-term use is preferable. The stability or weatherability of the composition to light or heat is correlated to the lifetime of the element. When the stability or weather resistance is good, the life is long. These characteristics are desirable for the element.

The liquid crystal dimming element has a normal mode (normal mode) and a reverse mode (reverse mode). In the normal mode, it is opaque when no voltage is applied and becomes transparent when a voltage is applied. In the reverse mode, it is transparent when no voltage is applied and becomes opaque when a voltage is applied. The normal mode element can be widely used, and has the advantages of being cheap and easy to manufacture.

Disclosure of Invention

Problems to be solved by the invention

The present invention addresses the problem of providing a liquid crystal composite suitable for dimming, which contains a liquid crystal composition that satisfies at least one of the characteristics of a high upper limit temperature of a nematic phase, a low lower limit temperature of the nematic phase, a low viscosity, a large optical anisotropy, a large positive dielectric anisotropy, a large specific resistance, a high stability to light, a high stability to heat, and a large elastic constant. Another object is to provide a liquid crystal composite suitable for dimming, which contains a liquid crystal composition having an appropriate balance between at least two of these characteristics. Still another object is to provide a liquid crystal light control element having such a liquid crystal composite. Still another object is to provide a liquid crystal light-controlling element having characteristics such as a short response time, a high voltage holding ratio, a low threshold voltage, a high haze ratio, and a long life.

Means for solving the problems

The present invention relates to a liquid crystal composite containing a liquid crystal composition containing at least one compound selected from compounds represented by formula (1) as a first component, and a polymer, a liquid crystal light-controlling element having the composite, and the like.

In the formula (1), R¹Is alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms, or alkenyl group having 2 to 12 carbon atoms; ring a 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; z¹Is a single bond, ethylene, carbonyloxy, or difluoromethyleneoxy; x¹And X²Independently hydrogen or fluorine; y is¹Is fluorine, chlorine, cyano, alkyl of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, alkoxy of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, or alkenyloxy of carbon number 2 to 12 with at least one hydrogen substituted by fluorine or chlorine; a is 1,2,3, or 4.

ADVANTAGEOUS EFFECTS OF INVENTION

The present invention is advantageous in that it provides a liquid crystal composite suitable for light control, which contains a liquid crystal composition that satisfies at least one of characteristics such as a high upper limit temperature of a nematic phase, a low lower limit temperature of the nematic phase, a low viscosity, a large optical anisotropy, a large positive dielectric anisotropy, a large specific resistance, a high stability to light, a high stability to heat, and a large elastic constant. Another advantage resides in providing a liquid crystal composite containing a liquid crystal composition having an appropriate balance between at least two of these characteristics and suitable for dimming. Still another advantage is to provide a liquid crystal dimming device having such a liquid crystal composite. Still another advantage is to provide a liquid crystal light modulating element having characteristics such as a short response time, a large voltage holding ratio, a low threshold voltage, a large haze ratio, and a long lifetime.

Detailed Description

In the specification, terms such as "liquid crystal compound", "polymerizable compound", "liquid crystal composition", "polymerizable composition", "liquid crystal composite", and "liquid crystal light control element" are used. The "liquid crystalline compound" is a general term for compounds having a liquid crystal phase such as a nematic phase or a smectic phase, and compounds which do not have a liquid crystal phase but are added to the composition for the purpose of adjusting the characteristics such as the temperature range, viscosity, and dielectric anisotropy of the nematic phase. The compound has a six-membered ring such as 1, 4-cyclohexylene or 1, 4-phenylene, and its molecular structure is rod-like (rod like). The "polymerizable compound" is a compound added for the purpose of forming a polymer in the liquid crystal composition. The liquid crystalline compound having an alkenyl group is not polymerizable in its meaning.

The "liquid crystal composition" is prepared by mixing a plurality of liquid crystalline compounds. Additives such as optically active compounds, antioxidants, ultraviolet absorbers, pigments, antifoaming agents, and polar compounds may be added to the liquid crystal composition as required. In the case where an additive is added, the proportion of the liquid crystalline compound is also represented by a weight percentage (wt%) based on the liquid crystal composition containing no additive. The proportion of the additive is represented by weight percent (wt%) based on the liquid crystal composition containing no additive. That is, the ratio of the liquid crystalline compound or the additive is calculated based on the total weight of the liquid crystalline compound.

The "polymerizable composition" is prepared by mixing a polymerizable compound into a liquid crystal composition. That is, the polymerizable composition is a mixture of at least one polymerizable compound and the liquid crystal composition. Additives such as a polymerization initiator, a polymerization inhibitor and a polar compound are added to the polymerizable compound as required. In the case where an additive is added, the proportion of the polymerizable compound or the liquid crystal composition is also represented by a weight percentage (wt%) based on the polymerizable composition containing no additive. The proportions of the additives such as the polymerization initiator, the polymerization inhibitor and the polar compound are expressed by weight percent (wt%) based on the liquid crystal composition. The "liquid crystal composite" is produced by polymerization treatment of the polymerizable composition. The "liquid crystal light control element" is a generic name of a liquid crystal panel and a liquid crystal module having a liquid crystal composite and used for light control.

The "upper limit temperature of the nematic phase" may be simply referred to as "upper limit temperature". The "lower limit temperature of the nematic phase" may be simply referred to as "lower limit temperature". The "large specific resistance" means that the composition has a large specific resistance in an initial stage and also has a large specific resistance after long-term use. The "large voltage holding ratio" means that the device has a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature in the initial stage, and also has a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after long-term use. The properties of the composition or the element are sometimes investigated by time-varying tests. The expression "increase in dielectric anisotropy" means that the value increases positively in a composition having positive dielectric anisotropy, and increases negatively in a composition having negative dielectric anisotropy.

The compound represented by the formula (1) may be simply referred to as "compound (1)". At least one compound selected from the compounds represented by formula (1) may be abbreviated as "compound (1)". The "compound (1)" means one compound, a mixture of two compounds, or a mixture of three or more compounds represented by the formula (1). The same applies to the compounds represented by the other formulae. The expression "at least one 'a'" means that the number of 'a's is arbitrary. The expression "at least one 'a' may be substituted with 'B' means that the position of 'a' is arbitrary when the number of 'a' is one, and the position thereof may be selected without limitation when the number of 'a' is two or more. The rules also apply to the expression "at least one 'a' is substituted with 'B'.

Sometimes in the description "at least one-CH₂-may be substituted by-O-and the like. In said case, -CH₂-CH₂-CH₂Can pass through non-contiguous-CH₂-conversion to-O-CH by-O-substitution₂-O-. However, adjacent-CH₂-is not substituted by-O-. The reason for this is that: in the substitution, the formation of-O-CH₂- (peroxides). That is, the expression means "one-CH₂-may be substituted by-O-with at least two non-adjacent-CH₂-may be substituted by-O- ". The rule applies not only to the case of substitution to-O-, but also to the case of substitution to a divalent group such as-CH ═ CH-or-COO-.

In the chemical formula of the component compound, the end group R¹The notation of (a) is used for a variety of compounds. In these compounds, any two R¹The two radicals indicated may be identical or else different. For example, R of the compound (1-1)¹Is ethyl, and R of the compound (1-2)¹In the case of ethyl. Also, there are R of the compound (1-1)¹R of the compound (1-2) is ethyl¹In the case of propyl. The rules apply to other tokens as well. In formula (1), when the subscript 'a' is 2, there are two rings a. In the compounds, the two groups represented by the two rings a may be the same or may be different. The rule also applies to any two rings a where subscript 'a' is greater than 2. The rules apply to other tokens as well. The rule also applies to the case where the compounds have substituents represented by the same symbols.

The symbols A, B, C, D and the like surrounded by hexagons correspond to the rings such as ring a, ring B, ring C, ring D, and the like, respectively, and represent the rings such as a six-membered ring, a condensed ring, and the like. In the expression "ring a and ring B are independently X, Y or Z", the subject is plural, and thus "independently" is used. When the subject is "ring a," independent "is not used since the subject is singular. In the case where "ring a" is used in a plurality of formulae, "the rule of" may be the same or may be different "applies to" ring a ". The same applies to the other groups.

2-fluoro-1, 4-phenylene refers to the following two divalent radicals. In the chemical formula, fluorine can be towards left (L) or right (R). The rules also apply to divalent radicals such as tetrahydropyran-2, 5-diyl that are asymmetric about left and right by removal of two hydrogens from the ring. The rules also apply to divalent bonding groups such as carbonyloxy (-COO-or-OCO-).

The alkyl group of the liquid crystalline compound is linear or branched and does not include a cyclic alkyl group. In the liquid crystalline compound, a linear alkyl group is preferable to a branched alkyl group. These cases are also the same for terminal groups such as alkoxy groups and alkenyl groups. In order to increase the upper limit temperature, the steric configuration associated with the 1, 4-cyclohexylene group is a trans configuration rather than a cis configuration.

The present invention is as follows.

Item 1. a liquid crystal composite containing a liquid crystal composition containing at least one compound selected from the compounds represented by formula (1) as a first component, and a polymer.

Item 2. the liquid crystal composite according to item 1, wherein the liquid crystal composition contains at least one compound selected from the group of compounds represented by formulae (1-1) to (1-47) as the first component.

In the formulae (1-1) to (1-47), R¹Is alkyl group having 1 to 12 carbon atoms, alkoxy group having 1 to 12 carbon atoms or alkenyl group having 2 to 12 carbon atoms, X¹And X²Independently hydrogen or fluorine; y is¹Is fluorine, chlorine, cyano, alkyl of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, alkoxy of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, or alkenyloxy of carbon number 2 to 12 with at least one hydrogen substituted by fluorine or chlorine.

Item 3. the liquid crystal composite according to item 1 or item 2, wherein the proportion of the first component ranges from 5% by weight to 90% by weight based on the weight of the liquid crystal composition.

Item 4. the liquid crystal composite according to any one of item 1 to item 3, wherein the liquid crystal composition contains at least one compound selected from the compounds represented by formula (2) as the second component.

In the formula (2), R²And R³Independently 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 or chlorine; ring B and ring C are independently 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, 2, 5-difluoro-1, 4-phenylene, or pyrimidine-2, 5-diyl; z²Is a single bond, ethylene, ethynylene, or carbonyloxy; b is 1,2, or 3.

Item 5. the liquid crystal composite according to any one of item 1 to item 4, wherein the liquid crystal composition contains at least one compound selected from the group of compounds represented by formulae (2-1) to (2-23) as the second component.

In the formulae (2-1) to (2-23), R²And R³Independently 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 or chlorine.

Item 6 the liquid crystal composite according to item 4 or item 5, wherein the proportion of the second component is in a range of 5 to 90% by weight based on the weight of the liquid crystal composition.

The liquid crystal composite according to any one of items 1 to 6, wherein the liquid crystal composition contains at least one compound selected from the compounds represented by formula (3) as a third component.

In the formula (3), R⁴And R⁵Independently 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 alkenyloxy group having 2 to 12 carbon atoms; ring D and ring F are independently 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene in which at least one hydrogen is substituted by fluorine or chlorine, naphthalene-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, chroman-2, 6-diyl, or chroman-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine; ring E is 2, 3-difluoro-1, 4-phenylene, 2-chloro-3-fluoro-1, 4-phenylene, 2, 3-difluoro-5-methyl-1, 4-phenylene, 3,4, 5-trifluoronaphthalene-2, 6-diyl, or 7, 8-difluorochroman-2, 6-diyl; z³And Z⁴Independently a single bond, ethylene, carbonyloxy, or methyleneoxy; c is 1,2 or 3, d is 0 or 1; the sum of c and d is 3 or less.

Item 8. the liquid crystal composite according to any one of item 1 to item 7, wherein the liquid crystal composition contains at least one compound selected from the group of compounds represented by formulae (3-1) to (3-22) as a third component.

In the formulae (3-1) to (3-22), R⁴And R⁵Independently 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 alkenyloxy group having 2 to 12 carbon atoms.

Item 9. the liquid crystal composite according to item 7 or item 8, wherein the proportion of the third component ranges from 3% by weight to 25% by weight based on the weight of the liquid crystal composition.

Item 10 the liquid crystal composite according to any one of item 1 to item 9, wherein the polymer is a polymer derived from a polymerizable compound containing at least one compound selected from the compounds represented by formula (4).

P¹-Z⁵-P²(4)

In the formula (4), Z⁵Is C1-20 alkylene, wherein at least one hydrogen may be substituted by C1-5 alkyl, fluorine, chlorine, or P³Substituted by at least one-CH₂May be substituted by-O-, -CO-, -COO-, -OCO-, -NH-, -N (R)⁶) -, -CH ═ CH-, or-C ≡ C-substituted, at least one-CH₂-may be substituted by a divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic saturated aliphatic compound, a carbocyclic or heterocyclic unsaturated aliphatic compound, or a carbocyclic or heterocyclic aromatic compound, in which the number of carbons is from 5 to 35 and at least one hydrogen may pass through R⁶Or P³Substituted, here, R⁶Is an alkyl group having 1 to 12 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-; p¹、P²And P³Independently a polymerizable group.

The liquid crystal complex according to item 10, wherein in formula (4), Z⁵Is C1-20 alkylene, wherein at least one hydrogen may be substituted by C1-5 alkyl, fluorine, chlorine, or P³Substituted by at least one-CH₂May be substituted by-O-, -CO-, -COO-, -OCO-, -NH-, -N (R)⁶) -, -CH ═ CH-, or-C ≡ C-substituted, and in these divalent groups, the carbon number is 5 to 35, and at least one hydrogen may pass through R⁶Or P³Substituted, here, R⁶Is an alkyl group having 1 to 12 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-; p¹、P²And P³Independently a polymerizable group.

Item 12 the liquid crystal complex according to item 10 or item 11, wherein in formula (4), P¹、P²And P³Independently a group selected from the group of polymerizable groups represented by the formulae (P-1) to (P-6).

The liquid crystal complex according to any one of item 10 to item 12, wherein in formula (4), P¹、P²And P³Is an acryloyloxy group or a methacryloyloxy group.

The liquid crystal composite according to any one of items 1 to 9, wherein the polymer is a polymer derived from a polymerizable compound containing at least one compound selected from the compounds represented by formula (5).

In the formula (5), M⁴And M⁵Independently hydrogen or methyl; z⁶Is alkylene group having 21 to 80 carbon atoms, in which at least one hydrogen may be substituted by alkyl group having 1 to 20 carbon atoms, fluorine, or chlorine, and at least one-CH₂May be substituted by-O-, -CO-, -COO-, -OCO-, -NH-, -N (R)⁶) -, -CH ═ CH-, or-C ≡ C-substituted where R is substituted⁶Is an alkyl group having 1 to 12 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

In formula (6), M⁶Is hydrogen or methyl; z⁷Is a single bond or an alkylene group having 1 to 5 carbon atoms, in which alkylene group at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-; r⁷Is an alkyl group having 1 to 40 carbon atoms, in which at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-, at least one-CH₂May be substituted by a divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic saturated aliphatic compound, a carbocyclic or heterocyclic unsaturated aliphatic compound, or a carbocyclic or heterocyclic aromatic compound, in which the carbon number is from 5 to 35 and at least one hydrogen may be substituted by an alkyl group of carbon number 1 to 12, of which at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

The liquid crystal complex of item 16, wherein in formula (6), M⁶Is hydrogen or methyl; z⁷Is a single bond or an alkylene group having 1 to 5 carbon atoms, in which alkylene group at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-; r⁷Is an alkyl group having 1 to 40 carbon atoms, in which at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

In the formulae (7), (8) and (9), the ring G, the ring I, the ring J, the ring K, the ring L and the ring M are independently 1, 4-cyclohexylene, 1, 4-phenylene, 1, 4-cyclohexenylene, pyridine-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, naphthalene-2, 6-diyl or fluorene-2, 7-diyl, and in these divalent groups, at least one hydrogen may be fluorine, chlorine, cyano, hydroxyl, methyl etherAcyl, trifluoroacetyl, difluoromethyl, trifluoromethyl, alkyl of 1 to 5 carbon atoms, alkoxy of 1 to 5 carbon atoms, alkoxycarbonyl of 2 to 5 carbon atoms, or alkanoyl of 1 to 5 carbon atoms; z⁸、Z¹⁰、Z¹²、Z¹³And Z¹⁷Independently is a single bond, -O-, -COO-, -OCO-, or-OCOO-; z⁹、Z¹¹、Z¹⁴And Z¹⁶Independently a single bond, -OCH₂-、-CH₂O-、-COO-、-OCO-、-COS-、-SCO-、-OCOO-、-CONH-、-NHCO-、-CF₂O-、-OCF₂-、-CH₂CH₂-、-CF₂CF₂-、-CH＝CHCOO-、-OCOCH＝CH-、-CH₂CH₂COO-、-OCOCH₂CH₂-、-CH＝CH-、-N＝CH-、-CH＝N-、-N＝C(CH₃)-、-C(CH₃) -N-, -N-, or-C ≡ C-; z¹⁵Is a single bond, -O-or-COO-; y is²Is hydrogen, fluorine, chlorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl of carbon number 1 to 20, alkenyl of carbon number 2 to 20, alkoxy of carbon number 1 to 20, or alkoxycarbonyl of carbon number 2 to 20; f and h are integers from 1 to 4; k and m are independently integers from 0 to 3; the sum of k and m is 1 to 4; e. g, i, j, l, and n are independently integers from 0 to 20; m⁷To M¹²Independently hydrogen or methyl.

Item 18. the liquid crystal composite according to any one of item 1 to item 17, wherein a proportion of the liquid crystal composition is in a range of 50 to 95 wt% and a proportion of the polymer is in a range of 5 to 50 wt%, based on the weight of the liquid crystal composite.

Item 19. the liquid crystal composite according to any one of items 1 to 18, wherein the precursor of the liquid crystal composite is a polymerizable composition containing a liquid crystal composition and a polymerizable compound, the polymerizable composition containing a photopolymerization initiator as an additive.

Item 20. a liquid crystal dimming element, wherein the dimming layer is the liquid crystal composite according to any one of items 1 to 19, the dimming layer is sandwiched by a pair of transparent substrates, and the transparent substrates have transparent electrodes.

Item 21 the liquid crystal dimming element of item 20, wherein the transparent substrate is a glass plate or an acrylic plate.

The liquid crystal dimming element of item 20, wherein the transparent substrate is a plastic film.

Item 23. a dimming window using the liquid crystal dimming element according to any one of items 20 to 22.

An intelligent window using the liquid crystal dimming element of any one of items 20 to 22.

Item 25. use of a liquid crystal composite according to any one of items 1 to 19 in a liquid crystal dimming element.

Item 26. use of a liquid crystal composite according to any one of items 1 to 19 in a liquid crystal dimming element in which the transparent substrate is a plastic film.

Item 27. use of a liquid crystal composite according to any one of item 1 to item 19 in a light control window.

Item 28. use of a liquid crystal composite according to any one of items 1 to 19 in a smart window.

The present invention also includes the following items. (a) The liquid crystal composite according to item 1, which comprises a liquid crystal comprising Y selected from the group consisting of those represented by the formula (1)¹A liquid crystal composition containing at least one of fluorine compounds as a first component, and a polymer. (b) The liquid crystal composite according to item 1, which comprises a liquid crystal comprising Y selected from the group consisting of those represented by the formula (1)¹A liquid crystal composition having at least one of cyano compounds as a first component, and a polymer.

The present invention also includes the following items. (c) The liquid crystal composite according to item 2, which contains a liquid crystal composition comprising at least one compound selected from the group consisting of the compound (1-1), the compound (1-2), the compound (1-3), the compound (1-9), the compound (1-13), the compound (1-16), the compound (1-21), the compound (1-22), the compound (1-23), the compound (1-24), the compound (1-27), the compound (1-28), the compound (1-33), the compound (1-36), the compound (1-41), and the compound (1-42) according to item 2 as a first component, and a polymer.

The present invention also includes the following items. (d) The liquid crystal composite according to item 5, which contains a liquid crystal composition comprising at least one compound selected from the group consisting of the compound (2-1), the compound (2-2), the compound (2-3), the compound (2-4), the compound (2-6), the compound (2-9), the compound (2-10), the compound (2-12), the compound (2-13), the compound (2-14), the compound (2-16), the compound (2-17), the compound (2-19), and the compound (2-21) according to item 5 as a second component, and a polymer.

The present invention also includes the following items. (e) The liquid crystal composite according to item 8, which contains a liquid crystal composition comprising at least one compound selected from the group of the compound (3-1), the compound (3-2), the compound (3-3), the compound (3-4), the compound (3-6), the compound (3-7), the compound (3-8), and the compound (3-10) according to item 8 as a third component, and a polymer.

The present invention also includes the following items. (a) The liquid crystal composite as described above, wherein the ratio of the liquid crystal composition is in the range of 50 to 90% by weight and the ratio of the polymer is in the range of 10 to 50% by weight based on the weight of the liquid crystal composite. (b) The liquid crystal composite as described above, wherein the ratio of the liquid crystal composition is in the range of 50 to 85% by weight and the ratio of the polymer is in the range of 15 to 50% by weight based on the weight of the liquid crystal composite. (c) The liquid crystal composite as described above, wherein the ratio of the liquid crystal composition is in the range of 60 to 80% by weight and the ratio of the polymer is in the range of 20 to 40% by weight based on the weight of the liquid crystal composite.

The liquid crystal dimming element of the present invention is explained in the following order. First, the structure of the liquid crystal composite will be explained. Second, the structure of the liquid crystal composition will be described. Thirdly, the main characteristics of the component compounds and the main effects of the compounds on the composition will be described. Fourth, the combination of the ingredients in the composition, the preferred proportions of the ingredients, and their basis are described. Fifth, preferred embodiments of the component compounds will be described. Sixth, preferred component compounds are shown. Seventh, a method for synthesizing the component compound will be explained. Eighth, additives that can be added to the composition will be described. Ninth, a polymerizable compound and a polymerizable composition will be described. Finally, the liquid crystal composite will be explained.

First, the structure of the liquid crystal composite will be explained. The liquid crystal composite can be obtained by polymerizing the polymerizable composition. The polymerizable composition is a mixture of a liquid crystal composition and a polymerizable compound. The liquid crystal composition has positive dielectric anisotropy. Additives may also be added to the composition. The additive is a photopolymerization initiator, a polar compound, or the like. The polymerizable composition provides a liquid crystal composite because a polymer produced by polymerization undergoes phase separation. That is, a liquid crystal composite is produced by combining a polymer and a liquid crystal composition. The liquid crystal composite is suitable for an element in a normal mode which is opaque when no voltage is applied and becomes transparent when a voltage is applied. The optical anisotropy of the liquid crystal composition is associated with the refractive index of the polymer and the transparency of the liquid crystal dimming element. Generally, a liquid crystal composition having a high optical anisotropy (Δ n) is preferred. The optical anisotropy is preferably 0.16 or more, and more preferably 0.18 or more.

In the polymer dispersion type device, the liquid crystal composition is dispersed in the polymer as droplets. Each droplet is independent and discontinuous. On the other hand, in the polymer network type element, the polymer has a three-dimensional lattice structure, and the liquid crystal composition is continuous while being surrounded by the lattice. In these elements, the ratio of the liquid crystal composition based on the liquid crystal composite is preferably large in order to efficiently generate light scattering. When the droplet or grid is large, the drive voltage is low. Therefore, the ratio of the polymer is preferably small from the viewpoint of low driving voltage. The response time is short when the drop or grid is small. Therefore, the proportion of the polymer is preferably large from the viewpoint of short response time.

The preferable proportion of the liquid crystal composition is in the range of 50 to 95% by weight based on the weight of the liquid crystal composite. The preferred ratio also ranges from 50 wt% to 90 wt%. Further, the preferable ratio is in the range of 50 to 85% by weight. Particularly preferred proportions are in the range of 60 to 80% by weight. Particularly preferred proportions are in the range of 70 to 80% by weight. The ratio of the polymer can be easily calculated because the total of the liquid crystal composite and the polymer is 100% by weight. The ratio of the polymer based on the liquid crystal composite is the same as the ratio of the polymerizable compound based on the polymerizable composition.

When the ratio of the liquid crystal composition to the polymer is in these ranges, a polymer network type element is produced. When the proportion of the polymer is large, a polymer-dispersed structure is mixed. On the other hand, when the proportion of the polymer is less than 5% by weight, a polymer-stabilized alignment type element is produced. It is simply referred to as a Polymer Stabilized Alignment (PSA) element. In example 1 of International publication No. 2012-050178, "the monomer is added in an amount of 0.5 wt% based on the liquid crystal material" (paragraph 0105). As is clear from the above description, a slight amount of a polymerizable compound is added to a liquid crystal material (liquid crystal composition) in a PSA element.

In the PSA element, the polymer adjusts the pretilt angle of the liquid crystal molecules. By optimizing the pretilt angle, the liquid crystal molecules are stabilized, and the response time of the element is shortened. On the other hand, in the polymer network type element of the normal mode, there is a difference in refractive index between the polymer and the liquid crystal molecules, and therefore light scattering is caused and the element becomes opaque. When a voltage is applied to the element, liquid crystal molecules are aligned perpendicular to the substrates, and the element becomes transparent. Thus, in the polymer network type element, unlike a Polymer Stabilized Alignment (PSA) element, a polarizing plate is not required.

Second, the structure of the liquid crystal composition will be described. The composition contains a plurality of liquid crystalline compounds. The composition may also contain additives. The additive is optically active compound, antioxidant, ultraviolet absorbent, pigment, defoaming agent, polymerization initiator, polymerization inhibitor, polar compound, etc. From the viewpoint of the liquid crystalline compound, the compositions are classified into composition a and composition B. The composition a may further contain other liquid crystalline compounds, additives, and the like in addition to the liquid crystalline compound selected from the compound (1), the compound (2), and the compound (3). The "other liquid crystalline compound" is a liquid crystalline compound different from the compound (1), the compound (2) and the compound (3). Such compounds are mixed in the composition for the purpose of further adjusting the properties.

The composition B substantially contains only a liquid crystalline compound selected from the group consisting of the compound (1), the compound (2) and the compound (3). "substantially" means that the composition B may contain additives but does not contain other liquid crystalline compounds. The amount of ingredients of composition B is small compared to composition a. From the viewpoint of cost reduction, composition B is superior to composition a. From the viewpoint that the characteristics can be further adjusted by mixing other liquid crystalline compounds, the composition a is superior to the composition B.

Thirdly, the main characteristics of the component compounds and the main effects of the compounds on the composition will be described. The main properties of the component compounds are summarized in Table 2. In the notation of Table 2, L means large or high, M means moderate, and S means small or low. Note L, M, S is a classification based on qualitative comparison between component compounds, and note 0 (zero) means infinitesimal.

TABLE 2 characterization of the Compounds

Compound (I)	Compound (1)	Compound (2)	Compound (3)
				Upper limit temperature	S～L	S～L	S～L
Viscosity of the oil	M～L	S～M	M～L
				Optical anisotropy	M～L	S～L	M～L
Dielectric anisotropy	S～L	0	M～L¹⁾
				Specific resistance	L	L	L

1) The value of the dielectric anisotropy is negative, and the notation indicates the magnitude of the absolute value

The main effects of the component compounds on the properties of the composition are as follows. The compound (1) improves dielectric anisotropy. The compound (2) raises the upper limit temperature or lowers the lower limit temperature. The compound (3) increases the dielectric constant in the minor axis direction of the liquid crystal molecules.

Fourth, the combination of the ingredients in the composition, the preferred proportions of the ingredients, and their basis are described. Preferred combinations of ingredients in the composition are the first ingredient + the second ingredient, the first ingredient + the third ingredient, or the first ingredient + the second ingredient + the third ingredient. Further, a preferable combination is the first component + the second component, or the first component + the second component + the third component.

The preferred proportion of the first component is about 5% by weight or more in order to improve the dielectric anisotropy, and about 90% by weight or less in order to lower the lower limit temperature. Even more preferred is a ratio in the range of about 10 wt% to about 85 wt%. A particularly preferred ratio is in the range of about 20% to about 80% by weight.

The preferable proportion of the second component is about 5% by weight or more in order to increase the upper limit temperature or decrease the lower limit temperature, and about 90% by weight or less in order to increase the dielectric anisotropy. Even more preferred is a ratio in the range of about 10 wt% to about 85 wt%. A particularly preferred ratio is in the range of about 20% to about 80% by weight.

The preferable ratio of the third component is about 3 wt% or more in order to increase the dielectric constant in the short axis direction of the liquid crystal molecules, and about 25 wt% or less in order to lower the lower limit temperature. Even more preferred is a ratio in the range of about 5 wt% to about 20 wt%. A particularly preferred ratio is in the range of about 5% to about 15% by weight.

Fifth, preferred embodiments of the component compounds will be described. In the formulae (1), (2) and (3), R¹Is an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, or an alkenyl group having 2 to 12 carbon atoms. Preferred R is for improving stability to light or heat¹Is an alkyl group having 1 to 12 carbon atoms.

R²And R³Independently 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 or chlorine. For increasing the upper limit temperature or decreasing the lower limit temperature, R is preferably²Or R³R is an alkenyl group having 2 to 12 carbon atoms, and is preferably selected from the group consisting of²Or R³Is an alkyl group having 1 to 12 carbon atoms.

R⁴And R⁵Independently an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, carbonAn alkenyl group having a number of 2 to 12, or an alkenyloxy group having a carbon number of 2 to 12. Preferred R is for improving stability to light or heat⁴Or R⁵Is an alkyl group having 1 to 12 carbon atoms, and R is preferably selected to increase the dielectric constant in the minor axis direction of the liquid crystal molecules⁴Or R⁵Is alkoxy with 1 to 12 carbon atoms.

Preferred alkyl groups are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or octyl. In order to lower the lower limit temperature, a more preferable alkyl group is a methyl group, an ethyl group, a propyl group, a butyl group, or a pentyl group.

Preferred alkoxy groups are methoxy, ethoxy, propoxy, butoxy, pentoxy, hexoxy, or heptoxy. In order to lower the lower limit temperature, a more preferable alkoxy group is a methoxy group or an ethoxy group.

Preferred alkenyl groups 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, or 5-hexenyl. Further preferable alkenyl group is vinyl, 1-propenyl, 3-butenyl, or 3-pentenyl in order to lower the lower limit temperature. The preferred steric configuration of-CH ═ CH-in these alkenyl groups depends on the position of the double bond. For the purpose of lowering the lower limit temperature and the like, the trans configuration is preferred among alkenyl groups such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl, 3-hexenyl. Among alkenyl groups such as 2-butenyl, 2-pentenyl, 2-hexenyl, the cis configuration is preferred.

Preferred alkenyloxy groups are vinyloxy, allyloxy, 3-butenyloxy, 3-pentenyloxy, or 4-pentenyloxy. In order to lower the lower limit temperature, a more preferred alkenyloxy group is an allyloxy group or a 3-butenyloxy group.

Preferred examples of alkyl groups in which at least one hydrogen is substituted by fluorine or chlorine are fluoromethyl, 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl, 5-fluoropentyl, 6-fluorohexyl, 7-fluoroheptyl, or 8-fluorooctyl. Further preferable examples are 2-fluoroethyl, 3-fluoropropyl, 4-fluorobutyl and 5-fluoropentyl for improving the dielectric anisotropy.

Preferred examples of alkenyl groups in which at least one hydrogen is substituted by fluorine or chlorine are 2, 2-difluorovinyl, 3-difluoro-2-propenyl, 4-difluoro-3-butenyl, 5-difluoro-4-pentenyl, or 6, 6-difluoro-5-hexenyl. Further preferable examples for lowering the lower limit temperature are 2, 2-difluorovinyl group or 4, 4-difluoro-3-butenyl group.

Ring a 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. In order to improve the optical anisotropy, ring A is preferably 1, 4-phenylene or 2-fluoro-1, 4-phenylene. In order to increase the upper limit temperature, the steric configuration associated with the 1, 4-cyclohexylene group is a trans configuration rather than a cis configuration. Tetrahydropyran-2, 5-diyl as

Preferably, it is

Ring B and ring C are independently 1, 4-cyclohexylene, 1, 4-phenylene, 2-fluoro-1, 4-phenylene, or 2, 5-difluoro-1, 4-phenylene. For increasing the upper temperature limit or for decreasing the lower temperature limit, ring B or ring C is preferably a 1, 4-cyclohexylene group, and for decreasing the lower temperature limit, ring B or ring C is preferably a 1, 4-phenylene group.

Ring D and ring F are independently 1, 4-cyclohexylene, 1, 4-cyclohexenylene, tetrahydropyran-2, 5-diyl, 1, 4-phenylene in which at least one hydrogen is substituted by fluorine or chlorine, naphthalene-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, chroman-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine, or chroman-2, 6-diyl in which at least one hydrogen is substituted by fluorine or chlorine. For lowering the lower limit temperature or for raising the upper limit temperature, ring D or ring F is preferably 1, 4-cyclohexylene, and for lowering the lower limit temperature, ring D or ring F is preferably 1, 4-phenylene.

Ring E is 2, 3-difluoro-1, 4-phenylene, 2-chloro-3-fluoro-1, 4-phenylene, 2, 3-difluoro-5-methyl-1, 4-phenylene, 3,4, 5-trifluoronaphthalene-2, 6-diyl, or 7, 8-difluorochroman-2, 6-diyl. The preferred ring E is 2, 3-difluoro-1, 4-phenylene for lowering the lower limit temperature, 2-chloro-3-fluoro-1, 4-phenylene for lowering the optical anisotropy, and 7, 8-difluorochroman-2, 6-diyl for increasing the dielectric constant in the short axis direction of the liquid crystal molecule.

Z¹Is a single bond, ethylene, carbonyloxy, or difluoromethyleneoxy. For raising the upper limit temperature, preferred is Z¹Is a single bond, and Z is preferably a bond for improving dielectric anisotropy¹Is difluoromethyleneoxy. Z²Is a single bond, ethylene, ethynylene, or carbonyloxy. Preferred Z is Z for improving stability to light or heat²Is a single bond. Z³And Z⁴Independently a single bond, ethylene, carbonyloxy, or methyleneoxy. For lowering the lower limit temperature, Z is preferable³Or Z⁴Is a single bond, and Z is preferably Z for lowering the lower limit temperature³Or Z⁴Is ethylene, and Z is preferably Z for increasing the dielectric constant in the minor axis direction of the liquid crystal molecules³Or Z⁴Is a methyleneoxy group.

a is 1,2,3, or 4. In order to lower the lower limit temperature, a is preferably 2, and in order to improve the dielectric anisotropy, a is preferably 3. b is 1,2, or 3. For lowering the lower limit temperature, b is preferably 1, and for raising the upper limit temperature, b is preferably 2 or 3.

c is 1,2, or 3; d is 0 or 1; the sum of c and d is 3 or less. For lowering the lower limit temperature, c is preferably 1, and for raising the upper limit temperature, c is preferably 2 or 3. For lowering the lower limit temperature, d is preferably 0, and for lowering the lower limit temperature, d is preferably 1.

X¹And X²Independently hydrogen or fluorine. For raising the upper limit temperature, X is preferable¹Or X²Is hydrogen, and X is preferably selected for improving the dielectric anisotropy¹Or X²Is fluorine.

Y¹Is fluorine, chlorine, cyano, alkyl of carbon number 1 to 12 with at least one hydrogen substituted by fluorine or chlorine, carbon with at least one hydrogen substituted by fluorine or chlorineAn alkoxy group having a number of 1 to 12, or an alkenyloxy group having a carbon number of 2 to 12 in which at least one hydrogen is substituted with fluorine or chlorine. For reducing the viscosity, Y is preferred¹Fluorine, Y is preferred for improving dielectric anisotropy¹Is cyano.

The polymer is derived from a polymerizable compound. The polymerizable compound may be used alone or as a mixture of a plurality of compounds. From the viewpoint of further adjusting the characteristics of the light control element, a mixture of a plurality of compounds is preferable. Examples of the polymerizable compound are compound (4), compound (5), compound (6), compound (7), compound (8), or compound (9). The polymerizable compound may be a mixture of compounds selected from the group of the compound (4) to the compound (9). The polymerizable compound may also be a mixture with a polymerizable compound other than the compounds (4) to (9). The polymerizable compound preferably contains 50% by weight or more of the compound (4), the compound (5), the compound (6), the compound (7), the compound (8), the compound (9), or a mixture thereof.

In the formula (4), Z⁵Is C1-20 alkylene, wherein at least one hydrogen may be substituted by C1-5 alkyl, fluorine, chlorine, or P³Substituted by at least one-CH₂May be substituted by-O-, -CO-, -COO-, -OCO-, -NH-, -N (R)⁶) -, -CH ═ CH-, or-C ≡ C-substituted, at least one-CH₂-may be substituted by a divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic saturated aliphatic compound, a carbocyclic or heterocyclic unsaturated aliphatic compound, or a carbocyclic or heterocyclic aromatic compound, in which the number of carbons is from 5 to 35 and at least one hydrogen may pass through R⁶Or P³And (4) substitution. Here, R⁶Is an alkyl group having 1 to 12 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

Examples of the divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic saturated aliphatic compound are 1, 4-cyclohexylene, decahydronaphthalene-2, 6-diyl, tetrahydropyran-2, 5-diyl, 1, 3-dioxane-2, 5-diyl, and the like. Examples of the divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic unsaturated aliphatic compound are 1, 4-cyclohexenylene, dihydropyran-2, 5-diyl, and the like. Examples of the divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic aromatic compound are a 1, 4-phenylene group, a 1, 4-phenylene group in which at least one hydrogen is substituted with fluorine, a 1,2,3, 4-tetrahydronaphthalene-2, 6-diyl group, a naphthalene-1, 2-diyl group, a pyrimidine-2, 5-diyl group, and the like.

Preferred Z⁵Is alkylene group having 1 to 20 carbon atoms, in which at least one hydrogen may be substituted by alkyl group having 1 to 5 carbon atoms, at least one-CH₂-may be substituted by-O-at least one-CH₂May be substituted by a divalent group formed by removing two hydrogens from a carbocyclic saturated aliphatic compound or a carbocyclic aromatic compound, and the number of carbons in these divalent groups is from 5 to 35. Further preferred is Z⁵Is alkylene group having 1 to 20 carbon atoms, in which at least one hydrogen may be substituted by alkyl group having 1 to 5 carbon atoms, at least one-CH₂-may be substituted by-O-.

Preferred Z is Z for improving compatibility with the liquid crystal composition⁵Containing a ring structure such as 1, 4-cyclohexylene or 1, 4-phenylene. For easy formation of the lattice structure, Z is preferred⁵Including chain structures such as alkylene groups. Examples of the compound (4) include compounds (4-1) to (4-5).

In the formula (4-1), p is an integer of 1 to 6, in the formula (4-2), q is an integer of 5 to 20, and in the formula (4-4), r is an integer of 1 to 15.

P¹、P²And P³Independently a polymerizable group. Preferred polymerizable groups are represented by the formulae (P-1) to (P-6). Further preferred polymerizable groups are represented by the formulae (P-1) to (P-3).

In the formulae (P-1) to (P-6), M¹、M²And M³Independently hydrogen, fluorine, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 5 carbon atoms in which at least one hydrogen is substituted with fluorine or chlorine. For the purpose of enhancing reactivity, M is preferred¹、M²Or M³Is hydrogen or methyl. Further preferred is M¹Hydrogen or methyl, further preferred M²Or M³Is hydrogen.

In the formula (5), M⁴And M⁵Independently hydrogen or methyl. For the purpose of enhancing reactivity, M is preferred⁴Or M⁵Is hydrogen.

Z⁶Is alkylene group having 21 to 80 carbon atoms, in which at least one hydrogen may be substituted by alkyl group having 1 to 20 carbon atoms, fluorine, or chlorine, and at least one-CH₂May be substituted by-O-, -CO-, -COO-, -OCO-, -NH-, -N (R)⁶) -, -CH ═ CH-, or-C ≡ C-substituted where R is substituted⁶Is an alkyl group having 1 to 12 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-. To achieve low voltage drive, Z is preferred⁶Is alkylene group having 21 to 60 carbon atoms, in which at least one hydrogen may be substituted by alkyl group having 1 to 20 carbon atoms, at least one-CH₂-may be substituted by-O-, -COO-, or-OCO-.

To achieve low voltage driving, Z is further preferable⁶Is an alkylene group in which at least one hydrogen is substituted with an alkyl group. When both hydrogens of the alkylene group are substituted with alkyl groups, steric hindrance is preferably prevented. For example, two alkyl groups are sufficiently separated, or an alkyl group having 1 to 5 carbon atoms is used in one of the alkyl groups. The same applies when at least three hydrogens are substituted with alkyl groups.

An example of the compound (5) is a compound (5-1).

In the formula (5-1), R⁸And R¹⁰Independently an alkyl group of carbon number 1 to 5, R⁹And R¹¹Independently an alkyl group of carbon number 5 to 20, in which at least one-CH₂May be substituted by-O-, -CO-, -COO-, or-OCO-, Z⁸Is alkylene with 10 to 30 carbon atoms, in which at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

Examples of the compound (5-1) include the compound (5-1-1) and the compound (5-1-2).

In the formulae (5-1-1) and (5-1-2), for example R⁸And R¹⁰Is ethyl, R⁹And R¹¹Independently is-CH₂OCOC₉H₁₉、-CH₂OCOC₁₀H₂₁、-CH₂OC₈H₁₇or-CH₂OC₁₁H₂₃。

In formula (6), M⁶Is hydrogen or methyl. For the purpose of enhancing reactivity, M is preferred⁶Is hydrogen.

Z⁷Is a single bond or an alkylene group having 1 to 5 carbon atoms, in which alkylene group at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-. Preferred Z⁷Is a single bond or an alkylene group having 1 to 5 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

R⁷Is an alkyl group having 1 to 40 carbon atoms, in which at least one hydrogen may be substituted by fluorine or chlorine, at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-, at least one-CH₂May be substituted by a divalent group generated by removing two hydrogens from a carbocyclic or heterocyclic saturated aliphatic compound, a carbocyclic or heterocyclic unsaturated aliphatic compound, or a carbocyclic or heterocyclic aromatic compound, in which the carbon number is from 5 to 35 and at least one hydrogen may be substituted by an alkyl group of carbon number 1 to 12, of which at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-. Preferred R⁷Is an alkyl group having a carbon number of 5 to 30. Further preferred is R⁷Is a branched alkyl group having 5 to 30 carbon atoms.

Examples of the compound (6) include the compounds (6-1) to (6-6).

In the formulae (6-1) to (6-5), R¹²Is an alkyl group having 5 to 20 carbon atoms, in which at least one-CH group₂-may be substituted by-O-, -CO-, -COO-, or-OCO-, R¹³And R¹⁴Independently an alkyl group of carbon number 3 to 10, in which at least one-CH₂-may be substituted by-O-, -CO-, -COO-, or-OCO-.

Z⁸、Z¹⁰、Z¹²、Z¹³And Z¹⁷Independently a single bond, -O-, -COO-, -OCO-, or-OCOO-. Z⁹、Z¹¹、Z¹⁴And Z¹⁶Independently a single bond, -OCH₂-、-CH₂O-、-COO-、-OCO-、-COS-、-SCO-、-OCOO-、-CONH-、-NHCO-、-CF₂O-、-OCF₂-、-CH₂CH₂-、-CF₂CF₂-、-CH＝CHCOO-、-OCOCH＝CH-、-CH₂CH₂COO-、-OCOCH₂CH₂-、-CH＝CH-、-N＝CH-、-CH＝N-、-N＝C(CH₃)-、-C(CH₃) N-, -N-, or-C ≡ C-. Z¹⁵Is a single bond, -O-, or-COO-. Preferred Z⁸、Z¹⁰、Z¹²、Z¹³Or Z¹⁷Is a single bond or-O-. Preferred Z⁹、Z¹¹、Z¹⁴Or Z¹⁶Is a single bond, -OCH₂-、-CH₂O-、-COO-、-OCO-、-CH₂CH₂-、-CH₂CH₂COO-, or-OCOCH₂CH₂-。

Y²Is hydrogen, fluorine, chlorine, trifluoromethyl, trifluoromethoxy, cyano, alkyl having 1 to 20 carbon atoms, alkenyl having 2 to 20 carbon atoms, alkoxy having 1 to 20 carbon atoms, or alkoxycarbonyl having 2 to 20 carbon atoms. Preferred is Y²Is cyano, alkyl, or alkoxy.

f and h are integers from 1 to 4; k and m are independently integers from 0 to 3; the sum of k and m is 1 to 4; e. g, i, j, l, and n are independently integers from 0 to 20.

M⁷To M¹²Independently hydrogen or methyl.

Examples of the compound (7) include compounds (7-1) to (7-24).

In the formulae (7-1) to (7-24), M7 is hydrogen or methyl, and e is an integer of 1 to 20.

Examples of the compound (8) include compounds (8-1) to (8-31).

In the formulae (8-1) to (8-31), M8 and M9 are independently hydrogen or methyl, and g and i are independently integers of 1 to 20.

Examples of the compound (9) include compounds (9-1) to (9-10).

In formulae (9-1) to (9-10), M¹⁰、M¹¹And M¹²Independently hydrogen or methyl, j, l, and n are independently integers from 1 to 20.

Sixth, preferred component compounds are shown. Preferred compounds (1) are the compounds (1-1) to (1-47) described in the item 2. Of these compounds, it is preferable that at least one of the first components is a compound (1-1), a compound (1-2), a compound (1-3), a compound (1-9), a compound (1-13), a compound (1-16), a compound (1-21), a compound (1-22), a compound (1-23), a compound (1-24), a compound (1-27), a compound (1-28), a compound (1-33), a compound (1-36), a compound (1-41), or a compound (1-42).

Preferred compound (2) is the compound (2-1) to the compound (2-23) described in the item 5. Of these compounds, at least one of the second components is preferably compound (2-1), compound (2-2), compound (2-3), compound (2-4), compound (2-6), compound (2-9), compound (2-10), compound (2-12), compound (2-13), compound (2-14), compound (2-16), compound (2-17), compound (2-19), or compound (2-21).

Preferred compound (3) is the compound (3-1) to the compound (3-22) described in the item 8. Of these compounds, it is preferable that at least one of the third components is compound (3-1), compound (3-2), compound (3-3), compound (3-4), compound (3-6), compound (3-7), compound (3-8), or compound (3-10). Preferably, at least two of the third components are a combination of the compound (3-1) and the compound (3-6), the compound (3-1) and the compound (3-10), the compound (3-3) and the compound (3-6), the compound (3-3) and the compound (3-10), the compound (3-4) and the compound (3-6), or the compound (3-4) and the compound (3-10).

Seventh, a method for synthesizing the component compound will be explained. These compounds can be synthesized using known methods. A synthesis method is exemplified. The compounds (1-9) and (1-16) were synthesized by the method described in Japanese patent laid-open No. 2-233626. The compound (2-1) is synthesized by the method described in Japanese patent laid-open publication No. 59-176221. The compound (3-1) is synthesized by the method described in Japanese patent laid-open No. Hei 2-503441. Antioxidants are commercially available. The compound having s of 1 of formula (11) described later can be obtained from Aldrich (Sigma Aldrich Corporation). The compound (11) having s of 7 and the like was synthesized by the method described in the specification of U.S. Pat. No. 3660505. The polymerizable compound may be commercially available or synthesized by a known method.

Compounds not described in the synthesis method can be synthesized by the methods described in the following written description: organic Synthesis (Organic Synthesis), Inc. (John Wiley & Sons, Inc.), (Organic Reactions), Inc. (John Wiley & Sons, Inc.)), (Organic Synthesis), Integrated Circuit (Pergeman Press), New Experimental chemistry lecture (Bolus), etc. The compositions are prepared from the compounds obtained in the manner described, using known methods. For example, the component compounds are mixed and then dissolved in each other by heating.

Eighth, additives that can be added to the composition will be described. Such additives include optically active compounds, antioxidants, ultraviolet absorbers, pigments, antifoaming agents, polymerization initiators, polymerization inhibitors, polar compounds, and the like. An optically active compound is added to the composition for the purpose of inducing a helical structure of liquid crystal molecules to impart a twist angle (torsion angle). Examples of such compounds are compound (10-1) to compound (10-5). The preferable proportion of the optically active compound is about 5% by weight or less. Even more preferred is a ratio in the range of about 0.01 wt% to about 2 wt%.

In order to prevent a decrease in specific resistance caused by heating in the atmosphere or to maintain a large voltage holding ratio at room temperature and at a temperature close to the upper limit temperature even after the device is used for a long time, an antioxidant is added to the composition. Preferable examples of the antioxidant are a compound (11) wherein s is an integer of 1 to 9, and the like.

In the compound (11), s is preferably 1,3, 5, 7 or 9. More preferably, s is 7. since the compound (11) having s of 7 has low volatility, it is effective for maintaining a large voltage holding ratio not only at room temperature but also at a temperature close to the upper limit temperature after the device is used for a long time. In order to obtain the above effect, the preferable ratio of the antioxidant is about 50ppm or more, and the preferable ratio of the antioxidant is about 600ppm or less so as not to lower the upper limit temperature or not to raise the lower limit temperature. Even more preferred ratios range from about 100ppm to about 300 ppm.

Preferable examples of the ultraviolet absorber are benzophenone derivatives, benzoate derivatives, triazole derivatives and the like. Light stabilizers such as sterically hindered amines are also preferred. The preferable proportion of these absorbents or stabilizers is about 50ppm or more in order to obtain the above effects, and about 10000ppm or less in order not to lower the upper limit temperature or not to raise the lower limit temperature. Even more preferred ratios range from about 100ppm to about 10000 ppm.

In order to be suitable for a guest-host (GH) mode element, a dichroic dye (dichromatic dye) such as an azo dye or an anthraquinone dye is added to the composition. The preferred proportion of pigment ranges from about 0.01% to about 10% by weight. In order to prevent foaming, an antifoaming agent such as dimethylsilicone oil or methylphenylsilicone oil is added to the composition. The preferable ratio of the defoaming agent is about 1ppm or more in order to obtain the above effects, and about 1000ppm or less in order to prevent display failure. Even more preferred ratios range from about 1ppm to about 500 ppm.

The polymerizable compound is polymerized by ultraviolet irradiation. The polymerization may be carried out in the presence of a polymerization initiator such as a photopolymerization initiator. The appropriate conditions for carrying out the polymerization, or the appropriate type and amount of initiator, are known to those of ordinary skill in the art to which the invention pertains and are described in the literature. For example, brilliant solid (Irgacure)651 (registered trademark; BASF), brilliant solid (Irgacure)184 (registered trademark; BASF), or Delocur (Darocur)1173 (registered trademark; BASF) as a photopolymerization initiator is suitable for radical polymerization.

When the polymerizable compound is stored, a polymerization inhibitor may be added to prevent polymerization. The polymerizable compound is usually added to the composition in a state where the polymerization inhibitor is not removed. Examples of the polymerization inhibitor are hydroquinone derivatives such as hydroquinone and methylhydroquinone, 4-t-butylcatechol, 4-methoxyphenol, phenothiazine and the like.

The polar compound is an organic compound having polarity. Here, no compound having an ionic bond is contained. Atoms such as oxygen, sulfur, and nitrogen are negatively charged and tend to have a partial negative charge. Carbon and hydrogen are neutral or tend to have a partial positive charge. Polarity arises because part of the charge is distributed unequally among the atoms of different species in the compound. For example, the polar compound has-OH, -COOH, -SH, -NH₂、>NH、>N-, or the like.

Ninth, a polymerizable compound and a polymerizable composition will be described. In the case where the compound (4) has a high polymerizability, the polymer surrounding the droplet becomes strong or the mesh becomes dense due to crosslinking. The polymerizable compound preferably has at least one acryloyloxy group (-OCO-CH ═ CH)₂) Or methacryloxy (-OCO- (CH)₃)C＝CH₂). The compound (4) provides a corresponding polymer by polymerization. When the compound (4) is volatile, an oligomer thereof may be used. Preferred polymers are colorlessTransparent and insoluble in the liquid crystal composition. The preferred polymer has excellent adhesion to the substrate of the element, and reduces the driving voltage. In order to enhance the above effect, a polymerizable compound different from the compound (4) may be used in combination.

The compound (5) is diacrylate or dimethacrylate. Z⁶Being an alkylene group or the like, the polymer easily forms a lattice structure. At Z⁶When the molecular chain of (2) is short, the crosslinked sites of the polymer are close to each other, and therefore the size of the lattice becomes small. At Z⁶When the molecular chain length of (2) is long, the crosslinked portion of the polymer is far away, and the degree of freedom of molecular motion is increased, so that the driving voltage is lowered. At Z⁶In the case of the branched structure, the degree of freedom is further improved, and thus the driving voltage is further reduced. In order to enhance the above effect, a polymerizable compound different from the compound (5) may be used in combination.

The compound (6) is acrylate or methacrylate. At R⁷When the compound has a cyclic structure, the affinity with the liquid crystal composition is improved. At R⁷In the case of alkylene, the polymer easily forms a lattice structure. In the polymer, the degree of freedom of molecular movement is increased by the alkylene group, and thus the driving voltage is decreased. In order to further enhance the above effect, a polymerizable compound different from the compound (6) may be used in combination.

The compound (7), the compound (8), and the compound (9) have at least one acryloyloxy group (-OCO-CH ═ CH)₂) Or methacryloxy (-OCO- (CH)₃)C＝CH₂). The liquid crystalline compounds have a mesogen (a portion exhibiting rigidity of liquid crystallinity), and these compounds also have a mesogen. Therefore, these compounds are aligned in the same direction together with the liquid crystalline compound by the action of the alignment layer. The orientation is also maintained after polymerization. The liquid crystal composite has high transparency. In order to improve other properties, a polymerizable compound different from the compound (7), the compound (8) and the compound (9) may be used in combination.

The polymerizable composition is a mixture of a liquid crystal composition and a polymerizable compound. Polar compounds may also be added to the liquid crystal composition. The polar group of the compound has a non-covalently bonded interaction with the surface of a glass substrate, a metal oxide film, or the like. The compound is adsorbed on the substrate surface by the action of polar groups, and controls the orientation of liquid crystal molecules. The polar compound may control not only the liquid crystal molecules but also the polymerizable compound. Such an effect is expected for polar compounds.

The method for producing a liquid crystal composite from the polymerizable composition is as follows. First, a polymerizable composition is sandwiched between a pair of substrates. Next, the polymerizable compound is polymerized by heat or light. The polymerization is preferably carried out by irradiating ultraviolet rays. By the polymerization, the polymer phase-separates from the polymerizable composition. Thereby, a liquid crystal layer (i.e., a light modulation layer) having a light modulation function is formed between the substrates. The light modulation layer is classified into a polymer dispersion type, a polymer network type, and a mixed existence type of the two.

Finally, the liquid crystal composite will be explained. The liquid crystal composite is used for a liquid crystal light control element and the like. The reason for this is that: the transparency/opacity of the element can be controlled by the voltage applied to the element. The element can be obtained by the following method. First, a polymerizable composition is sandwiched between a pair of transparent substrates having at least one transparent electrode at a temperature higher than the upper limit temperature by a vacuum injection method or a liquid crystal dropping method. Next, the polymerizable compound in the polymerizable composition is polymerized by heat or irradiation with ultraviolet rays. At this time, a light control layer having a liquid crystal composition and a polymer can be formed, and thus a liquid crystal light control element can be obtained.

Examples of the substrate include a glass plate, a quartz plate, and an acrylic plate, which are hardly deformed. Another example is a flexible transparent plastic film such as an acrylic film or a polycarbonate film. Depending on the application, one of the substrates may be an opaque material such as silicone resin. The substrate has a transparent electrode thereon. An alignment film or the like may be provided over the transparent electrode. Examples of transparent electrodes are Indium Tin Oxide (ITO) or conductive polymers.

As the alignment layer on the substrate, a film of polyimide or polyvinyl alcohol is suitable. For example, the polyimide alignment film can be obtained by coating a polyimide resin composition on a transparent substrate, and thermally hardening at a temperature of about 180 ℃ or higher, and if necessary, performing a rubbing treatment by cotton cloth or rayon cloth.

The pair of substrates are opposed to each other so that the transparent electrode layers are positioned inside. Spacers may also be placed in order to make the thickness uniform between the substrates. Examples of the spacer are glass particles, plastic particles, alumina particles, optical spacers (photospacers), and the like. The preferred thickness of the light-modulating layer is from about 2 μm to about 50 μm, and more preferably from about 5 μm to about 20 μm. When a pair of substrates is bonded, a general-purpose sealant can be used. An example of the sealant is an epoxy thermosetting composition.

The polymerizable compound is preferably irradiated with ultraviolet light during polymerization. Examples of the ultraviolet radiation lamp include a metal halide lamp, a high-pressure mercury lamp, and an ultra-high-pressure mercury lamp. When a photopolymerization initiator is used, the wavelength of ultraviolet rays is preferably in the absorption wavelength region of the photopolymerization initiator. Avoiding the absorption wavelength range of the liquid crystal composition. The preferred wavelength is 330nm or more. Further, the preferable wavelength is 350nm or more. The reaction may be carried out at around room temperature, or may be carried out by heating.

In such an element, a light absorbing layer, a diffusion reflection plate, and the like may be disposed on the back surface of the element as necessary. The functions of mirror reflection, diffuse reflection, regressive reflection, holographic reflection and the like can also be added.

Such an element functions as a light control film or a light control glass. When the element is in the form of a film, the element may be attached to an existing window or may be sandwiched between a pair of glass plates to form a laminated glass. Such elements are used for windows arranged in the outer walls or for the separation of conference rooms from corridors. That is, there are applications such as electronic blinds, light control windows, smart windows, and the like. Further, the function as an optical switch can be applied to a liquid crystal shutter or the like.

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