JP2019028458A - Liquid crystal capsule and production method of the same - Google Patents

Abstract

To provide a liquid crystal capsule having a particle diameter smaller than a lower limit of the wavelength region of visible light so as to exhibit optical anisotropy, and a production method of the liquid crystal capsule.SOLUTION: A liquid crystal capsule that is strong and has a particle diameter smaller than a lower limit (about 380 nm) of the wavelength region of visible light is obtained by using a styrene maleic acid anhydride copolymer as a surfactant and a melamine prepolymer for forming a capsule wall. The present invention also provides a production method of the liquid crystal capsule.SELECTED DRAWING: None

Description

  The present invention relates to a liquid crystal capsule and a manufacturing method thereof. In particular, the present invention relates to a liquid crystal capsule having an average particle diameter of about 10 nm to 380 nm and a method for producing the same so as to be optically isotropic.

Liquid crystal capsules having a structure in which a liquid crystal composition is encapsulated in a hollow portion of the capsule are used as liquid crystal display elements, and are expected to be used particularly in flexible displays (for example, Patent Document 1, Patent Document 2, Patent Document 3 and Non-Patent Document 1).
Specifically, a liquid crystal display element is known that is applied to a comb-shaped (lateral electric field) substrate using a bar coater or the like and a mixture containing a liquid crystal capsule and a binder (resin) is driven by only one side substrate. Yes. Such a liquid crystal display element is driven using the Kerr effect.

  When a liquid crystal capsule is used for such a liquid crystal display element driven by only one side substrate, if the particle size of the liquid crystal capsule exceeds the lower limit of the wavelength range of visible light (about 380 nm), the scattering of visible light increases, and black It becomes difficult to display.

JP-A-8-67878 JP2010-2111182 Korean registered patent 1506328

Optics EXPRESS Vol. 21, No. 13 P15719-15727 (1 July 2013)

  Under the above circumstances, a liquid crystal capsule having a particle size smaller than the lower limit of the wavelength range of visible light so as to be optically isotropic, and a method for producing the same are desired.

The inventors mix a liquid crystal composition (a composition comprising one or more liquid crystal compounds) and a surfactant, and prepare a microemulsion and a nanoemulsion therefrom using an emulsifier such as a homogenizer, It came to invent the liquid crystal capsule manufactured through the process which mixes the said nanoemulsion and a monomer and manufactures a liquid crystal capsule using an in-situ polymerization method, and its manufacturing method.
Here, the microemulsion is an emulsion composed of droplets having a number average particle size of several micrometers to several hundreds of micrometers, and the nanoemulsion is composed of droplets having a number average particle diameter of several nanometers to several hundreds of nanometers. It is an emulsion.

The present invention includes, for example, the following aspects of the invention.
First, a liquid crystal capsule in which a liquid crystal composition is covered with a melamine resin or a urea-formalin resin. Next, Step A for preparing a microemulsion from a mixed material obtained by mixing a liquid crystal composition and a surfactant, Step B for preparing a nanoemulsion from the microemulsion, and mixing a melamine prepolymer into the nanoemulsion. And a liquid crystal capsule manufacturing method including the step C of manufacturing the liquid crystal capsule.

  According to the present invention, a liquid crystal capsule having an average particle diameter smaller than the lower limit (about 380 nm) of the visible light wavelength region can be obtained so as to be optically isotropic.

The present invention includes the following items.
Item 1. A liquid crystal capsule having an average particle diameter of 10 nm to 380 nm, wherein the liquid crystal composition is covered with a capsule wall made of a melamine resin or a urea-formalin resin.

Item 2. Item 2. The liquid crystal capsule according to item 1, wherein the liquid crystal composition is covered with a capsule wall made of melamine resin.

式（１）および式（２）において、Ｒ^１、Ｒ^２およびＲ^３は独立して、炭素数１から１２のアルキル、炭素数１から１２のアルコキシ、または炭素数２から１２のアルケニルであり；環Ａ^１、Ａ^２、Ａ^３、Ａ^４およびＡ^５は独立して、１，４−シクロへキシレン、１，４−フェニレン、２−フルオロ−１，４−フェニレン、２，５−ジフルオロ−１，４−フェニレン、２，６−ジフルオロ−１，４−フェニレン、ピリジン−２，５−ジイル、ピリミジン−２，５−ジイル、１，３−ジオキサン−２，５−ジイル、またはテトラヒドロピラン−２，５−ジイルであり；Ｚ^１、Ｚ^２、Ｚ^３、Ｚ^４およびＺ^５は独立して、単結合、エチレン、ビニレン、メチレンオキシ、カルボニルオキシ、ジフルオロメチレンオキシ、エチニレン、またはテトラフルオロエチレンであるが、Ｚ^１およびＺ^２のうち、少なくとも１つはエチニレンであり；Ｘ^１、Ｘ^２、Ｘ^３、Ｘ^４、Ｘ^５およびＸ^６は独立して、水素またはフッ素であるが、Ｘ^１およびＸ^２が同時にフッ素であることはなく、Ｘ^４およびＸ^５が同時にフッ素であることはなく；Ｙ^１はフッ素、塩素、少なくとも１つの水素がハロゲンで置き換えられた炭素数１から１２のアルキル、少なくとも１つの水素がハロゲンで置き換えられた炭素数１から１２のアルコキシ、または少なくとも１つの水素がハロゲンで置き換えられた炭素数２から１２のアルケニルであり；ｌは、１または２であり、ｍは、０，１または２であり、ｌおよびｍが２を表す場合、複数存在する環Ａ^２、環Ａ^４、Ｚ^２およびＺ^４は、それぞれ同じであっても、異なっていてもよい。 Item 3. The liquid crystal composition is at least one compound selected from the group of compounds represented by the formula (1) as the liquid crystal compound 1, and at least selected from the group of compounds represented by the formula (2) as the liquid crystal compound 2. Item 3. The liquid crystal capsule according to item 1 or 2, wherein the proportion of the compound containing one compound and having cyano is less than 3% by weight with respect to the entire liquid crystal composition.

In Formula (1) and Formula (2), R ¹ , R ² and R ³ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons. Rings A ¹ , A ² , A ³ , A ⁴ and A ⁵ are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro; -1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran be a ^{2,5-diyl; Z 1, Z 2, Z} 3, Z 4 and ^{Z 5} are each independently a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy ethynylene, While others are tetrafluoroethylene, of ^{Z 1} and ^{Z 2,} at least one is an ^{ethynylene; X 1, X 2, X} 3, X 4, X 5 and ^{X 6} are each independently hydrogen or fluorine But X ¹ and X ² are not simultaneously fluorine and X ⁴ and X ⁵ are not simultaneously fluorine; Y ¹ is fluorine, chlorine, carbon in which at least one hydrogen is replaced by halogen An alkyl having 1 to 12 carbon atoms, an alkoxy having 1 to 12 carbon atoms in which at least one hydrogen is replaced by a halogen, or an alkenyl having 2 to 12 carbon atoms in which at least one hydrogen is replaced by a halogen; or a 2, m is 0, 1 or 2, if l and m is 2, ^the ring ^{a 2} there are a plurality of, ring ^a 4, ^{Z 2} and ^{Z 4,} respectively Even Flip, it may be different.

式（３）において、Ｒ^４およびＲ^５は独立して、炭素数１から１２のアルキル、炭素数１から１２のアルコキシ、または炭素数２から１２のアルケニルであり；環Ａ^６または環Ａ^７は独立して、１，４−シクロへキシレン、１，４−フェニレン、２−フルオロ−１，４−フェニレン、２，５−ジフルオロ−１，４−フェニレン、または２，６−ジフルオロ−１，４−フェニレンであり；Ｚ^６は、単結合、エチレン、ビニレン、メチレンオキシ、カルボニルオキシ、ジフルオロメチレンオキシ、エチニレン、またはテトラフルオロエチレンであり；Ｚ^７は、単結合、エチレン、ビニレン、メチレンオキシ、カルボニルオキシ、ジフルオロメチレンオキシ、またはテトラフルオロエチレンであり；ｎは、０、１または２であり、ｎが２を表す場合、複数存在する環Ａ^７およびＺ^７は、それぞれ同じであっても、異なっていてもよく；ただし、式（１）で表される化合物は除く。 Item 4. Item 4. The liquid crystal capsule according to item 3, wherein the liquid crystal composition further contains at least one compound selected from the group of compounds represented by formula (3) as the liquid crystal compound 3.

In Formula (3), R ⁴ and R ⁵ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons; ring A ⁶ or ring A ⁷ Are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, or 2,6-difluoro-1, be a 4-phenylene; Z ⁶ is a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy ethynylene or be a tetrafluoroethylene,; Z ⁷ is a single bond, ethylene, vinylene, methyleneoxy, Carbonyloxy, difluoromethyleneoxy or tetrafluoroethylene; n is 0, 1 or 2 and n represents 2 If, ring A ^7, and Z ⁷ there is a plurality, even in each same or different; provided that the compound represented by the formula (1) is excluded.

Item 5. The liquid crystal composition has an optical anisotropy at a wavelength of 589 nm measured at 25 ° C. in the range of 0.20 to 0.35, and a dielectric anisotropy at a frequency of 1 kHz measured at 25 ° C. in the range of 8 to 40. Item 5. The liquid crystal capsule according to any one of Items 1 to 4, wherein

Item 6. Item 6. The method for producing a liquid crystal capsule according to any one of Items 1 to 5.

Item 7. Step A for preparing a microemulsion from a mixed material obtained by mixing a liquid crystal composition and a surfactant, Step B for preparing a nanoemulsion from the microemulsion, and a liquid crystal prepared by mixing a melamine prepolymer into the nanoemulsion. Item 7. The method for producing a liquid crystal capsule according to Item 6, comprising Step C for producing the capsule.

Item 8. Item 8. The method for producing a liquid crystal capsule according to Item 6 or 7, wherein the surfactant comprises a hydrolyzate of an electron donating monomer and maleic anhydride copolymer in radical polymerization.

Item 9. Item 9. The method for producing a liquid crystal capsule according to any one of Items 6 to 8, wherein the surfactant comprises a hydrolyzate of 1-octadecene-maleic anhydride copolymer.

Item 10. Item 8. The method for producing a liquid crystal capsule according to Item 6 or 7, wherein the surfactant contains a hydrolyzate of a styrene-maleic anhydride copolymer.

Item 11. Item 9. The method for producing a liquid crystal capsule according to any one of items 6 to 8, wherein the surfactant used in the method for producing a liquid crystal capsule has a weight average molecular weight of 1,000 to 500,000.

Item 12. Item 12. The method for producing a liquid crystal capsule according to any one of Items 6 to 11, wherein a high-pressure atomizer is used in Step B.

Item 13. Item 13. The method for producing a liquid crystal capsule according to any one of Items 6 to 12, wherein the content of the surfactant is 1 to 50 parts by weight with respect to 100 parts by weight of the liquid crystal composition.

Item 14. Item 14. The method for producing a liquid crystal capsule according to any one of Items 6 to 13, wherein the content of the capsule wall is 1 to 60 parts by weight with respect to 100 parts by weight of the liquid crystal composition.

Item 15. Item 15. The method for producing a liquid crystal capsule according to any one of items 6 to 14, wherein the content of the liquid crystal composition is 50 to 90% by weight with respect to the total amount of the liquid crystal capsule.

1. Liquid crystal capsule The liquid crystal capsule of the present invention comprises a liquid crystal composition containing a liquid crystal compound, a surfactant and a capsule wall. Specifically, the capsule wall has a closed curved surface shape, and the liquid crystal composition is disposed inside the capsule wall. Further, the hydrophilic part of the surfactant 2 is further arranged inside the capsule wall, and the hydrophobic group of the surfactant is arranged outside the liquid crystal composition. Specific examples of the closed curved surface include a spherical surface and an elliptic spherical surface. The composition of the capsule wall is not particularly limited, but a polymer is preferable, and a melamine polymer is more preferable.
The liquid crystal composition is a material composed of one or two or more liquid crystal compounds. The surfactant may be a single compound or a plurality of compounds.

  The average particle diameter of the liquid crystal capsule is 10 to 380 nm. From the viewpoint of display quality, the average particle diameter of the liquid crystal capsule is preferably 30 to 250 nm, and more preferably 30 to 200 nm. In the present specification, the “average particle diameter” is an average value based on the number of particle diameters measured 50 times by a light scattering method at 25 ° C.

  In general, the obtained liquid crystal capsules are dispersed in water, but are used in a solution state to which a binder material or the like is added. Further, one or more binder materials may be used. As the binder material, PVA (polyvinyl alcohol) or a water-soluble compound such as melamine that can be used as a capsule wall can be used. Also, a vinyl chloride, vinyl acetate, acrylic or silicone emulsion dispersed in water can be used. As long as the content in the liquid crystal capsule does not leak, the solvent substitution of water as a dispersion can be performed, and a compound that is soluble in the substituted solvent can also be used as the binder material. Further, the binder material can be reacted in a subsequent process.

2. Method for Producing Liquid Crystal Capsule The method for producing a liquid crystal capsule of the present invention comprises a step A in which a microemulsion is prepared in a mixed material containing a liquid crystal composition and a surfactant using an emulsifying device, followed by a step B in which a nanoemulsion is prepared. And Step C for producing a liquid crystal capsule by mixing the nanoemulsion with a melamine prepolymer. Step C will be further described in detail. A monomer is mixed in the nanoemulsion and a capsule wall is constructed by an in-situ polymerization method.

2-1 Microemulsion preparation process (Process A)
When the liquid crystal composition is added little by little while stirring the surfactant solution with a homogenizer or the like, a micro-sized oil-in-water emulsion (O / W emulsion) is formed.
Hereinafter, the surfactant and the liquid crystal composition contained in the mixed material will be described.

2-1-1. Surfactant Although the surfactant used in the method for producing a liquid crystal capsule of the present invention is not particularly limited as long as it has surface activity, it preferably has affinity for both the liquid crystal composition and the surface of the capsule wall.

  Surfactants that are compatible with both the liquid crystal composition and the capsule wall surface are compounds that share hydrophobicity and hydrophilicity, such as glycerin, ethylene glycol, diethylene glycol, monoethyl ether, butanediol, propylene glycol, As the surfactant used in the method for producing a liquid crystal capsule of the present invention, it is preferable to use a hydrolyzate of a copolymer of an electron donating monomer and maleic anhydride in radical polymerization. Hydrolyzate of copolymer of styrene and maleic anhydride, hydrolyzate of copolymer of alkenyl and maleic anhydride, and hydrolysis of copolymer of ether and maleic anhydride It is more preferable to use a decomposition product, and the hydrolysis of the styrene-maleic anhydride copolymer Hydrolyzate, 1-octadecene - hydrolyzate of maleic anhydride copolymer, and 2-ethylhexyl vinyl ether - it is particularly preferable to use maleic anhydride copolymer hydrolyzate.

  If these compounds have too high molecular weight, they will not dissolve in water, and their viscosity will increase and mixing will be difficult. The weight average molecular weight of the surfactant of the present invention is preferably from 1,000 to 500,000, particularly preferably from 5,000 to 50,000.

  The content of the surfactant is preferably 1 to 50 parts by weight, more preferably 5 to 40 parts by weight with respect to 100 parts by weight of the liquid crystal composition.

2-1-2. Liquid crystal composition The liquid crystal composition can be used as a composition having a nematic phase, or can be used as an optically active composition by adding an optically active compound.
The liquid crystal composition contains a liquid crystal compound, and may optionally further contain additives such as an optically active compound, an antioxidant, an ultraviolet absorber, and a dichroic dye.
A liquid crystal composition having a positive dielectric anisotropy has a minimum temperature of a nematic phase of about −10 ° C. or lower, a maximum temperature of about 70 ° C. or higher, and an optical anisotropy of about 0.20 to about 0.35. And having a dielectric anisotropy in the range of about 8 to about 40.
A liquid crystal composition having negative dielectric anisotropy has a minimum temperature of a nematic phase of about −10 ° C. or lower, a maximum temperature of about 70 ° C. or higher, and an optical anisotropy of about 0.08 to about 0.35. And having a dielectric anisotropy in the range of about -2 to about -20. A device containing a liquid crystal composition has a large voltage holding ratio. These liquid crystal compositions are suitable for an AM device, and particularly suitable for a transmissive AM device.

(1) Liquid crystal compound contained in the liquid crystal composition The liquid crystal compound contained in the liquid crystal composition used for the mixed material is not particularly limited as long as it is compatible with the monomer and hardly soluble in water. Examples of the liquid crystal composition containing a liquid crystal compound include nematic liquid crystals, smectic liquid crystals, cholesteric liquid crystals, and chiral nematic liquid crystals. Among these, nematic liquid crystals are preferable.

表１中、Ｌは大きいまたは高い、Ｍは中程度の、Ｓは小さいまたは低い、を意味する。記号Ｌ、Ｍ、Ｓは、成分化合物のあいだの定性的な比較に基づいた分類であり、０（ゼロ）は、値がほぼゼロであることを意味する。液晶化合物２の誘電率異方性は正であり、液晶化合物４の誘電率異方性は負であり、表中の記号は、それぞれ誘電率異方性の絶対値の大小を示す。 The liquid crystal composition preferably includes liquid crystal compounds having different characteristics. Specifically, it is preferable to have predetermined characteristics with respect to the upper limit temperature, viscosity, optical anisotropy, dielectric anisotropy, specific resistance and the like of the nematic phase. In the liquid crystal composition used in the present invention, the liquid crystal compound 1 represented by the formula (1) and, if necessary, the liquid crystal compound 3 represented by the formula (3) are used. The liquid crystal composition having positive dielectric anisotropy is the liquid crystal compound 2 represented by formula (2), and the liquid crystal composition having negative dielectric anisotropy is the liquid crystal compound represented by formula (4). 4 is used. The characteristics of the liquid crystal compounds 1 to 4 are summarized below.
From the viewpoint of specific resistance and voltage holding ratio, the proportion of the compound having cyano is preferably less than 3% by weight with respect to the entire liquid crystal composition.

In Table 1, L means large or high, M means moderate, and S means small or low. The symbols L, M, and S are classifications based on a qualitative comparison among the component compounds, and 0 (zero) means that the value is almost zero. The dielectric anisotropy of the liquid crystal compound 2 is positive, the dielectric anisotropy of the liquid crystal compound 4 is negative, and the symbols in the table indicate the magnitude of the absolute value of the dielectric anisotropy.

  When the liquid crystal compound 1 is used, the optical anisotropy of the liquid crystal composition tends to increase, and when the liquid crystal compound 2 is used, the dielectric anisotropy of the liquid crystal composition increases positively (dielectric constant in the major axis direction). When the liquid crystal compound 3 is used, the optical anisotropy of the liquid crystal composition tends to increase, the upper limit temperature of the nematic phase increases, or the lower limit temperature of the nematic phase tends to decrease. Show. When the liquid crystal compound 4 is used, the dielectric anisotropy of the liquid crystal composition tends to increase negatively (the dielectric constant in the minor axis direction increases). The liquid crystal compound 4 is added for the purpose of adjusting the elastic constant of the liquid crystal composition and adjusting the voltage-transmittance curve of the device.

  The liquid crystal composition having positive dielectric anisotropy preferably includes liquid crystal compound 1 and liquid crystal compound 2, and more preferably includes liquid crystal compound 1, liquid crystal compound 2, and liquid crystal compound 3. The liquid crystal composition having negative dielectric anisotropy preferably includes liquid crystal compound 1 and liquid crystal compound 4, and more preferably includes liquid crystal compound 1, liquid crystal compound 3, and liquid crystal compound 4. In addition, it is preferable that the liquid crystal compounds 1-4 are each comprised from the some compound.

  In the liquid crystal composition, in order to obtain good optical anisotropy and good maximum temperature of the nematic phase, the preferred ratio of the liquid crystal compound 1 is preferably 20 to 70% by weight based on the total amount of the liquid crystal composition, 25 -70 wt% is more preferable, and 30-65 wt% is particularly preferable.

  In the liquid crystal composition, in order to obtain good optical anisotropy and good positive dielectric anisotropy, the preferred ratio of the liquid crystal compound 2 is preferably 25 to 75% by weight based on the total amount of the liquid crystal composition. 30 to 75% by weight is more preferable, and 35 to 70% by weight is particularly preferable.

  In the liquid crystal composition, in order to obtain good optical anisotropy and good minimum temperature of the nematic phase, the preferred ratio of the liquid crystal compound 3 is preferably 10 to 55% by weight based on the total amount of the liquid crystal composition. -50% by weight is more preferable, and 10-45% by weight is particularly preferable.

In the liquid crystal composition, in order to obtain good optical anisotropy and good negative dielectric anisotropy, the preferred ratio of the liquid crystal compound 4 is preferably 10 to 80% by weight based on the total amount of the liquid crystal composition. More preferably, it is 15 to 70% by weight.

（式（１）において、Ｒ^１およびＲ^２は独立して、炭素数１から１２のアルキル、炭素数１から１２のアルコキシ、または炭素数２から１２のアルケニルであり；環Ａ^１、Ａ^２は独立して、１，４−シクロへキシレン、１，４−フェニレン、２−フルオロ−１，４−フェニレン、２，５−ジフルオロ−１，４−フェニレン、２，６−ジフルオロ−１，４−フェニレン、ピリジン−２，５−ジイル、ピリミジン−２，５−ジイル、１，３−ジオキサン−２，５−ジイル、またはテトラヒドロピラン−２，５−ジイルであり；Ｚ^１およびＺ^２は独立して、単結合、エチレン、ビニレン、メチレンオキシ、カルボニルオキシ、ジフルオロメチレンオキシ、エチニレン、またはテトラフルオロエチレンであるが、Ｚ^１およびＺ^２のうち、少なくとも１つはエチニレンであり；Ｘ^１、Ｘ^２およびＸ^３は独立して、水素またはフッ素であるが、Ｘ^１およびＸ^２が同時にフッ素であることはなく；ｌは、１または２であり、ｌが２を表す場合、複数存在する環Ａ^２およびＺ^２は、それぞれ同じであっても、異なっていてもよい。） Examples of the liquid crystal compound 1 include a compound represented by the following formula (1).

(In Formula (1), R ¹ and R ² are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons; ring A ¹ , A ² Are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4. -Phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; Z ¹ and Z ² are independently and a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy ethynylene, or tetrafluoroethylene, one of Z ¹ and Z ^2, less Also one is an ^ethynylene; X 1, ^{X 2} and ^{X 3} are independently hydrogen or fluorine, never ^{X 1} and ^{X 2} are simultaneously fluorine; l is 1 or 2 , L represents 2, a plurality of the rings A ² and Z ² may be the same or different from each other.)

であり、好ましくは

である。 Tetrahydropyran-2,5-diyl is

And preferably

It is.

The liquid crystal compound 1 is preferably a compound represented by the following formula (1-1) among the compounds represented by the formula (1). Among the compounds represented by the formula (1-1), compounds represented by the formulas (1-1-1) to (1-1-13) are preferable.

(In the formula (1-1) and the formulas (1-1-1) to (1-1-13), R ¹¹ and R ²¹ are independently alkyl having 1 to 12 carbons and having 1 to 12 carbons. Alkoxy is alkenyl having 2 to 12 carbons; ring A ¹¹ is 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro-1, 4-phenylene, or 2,6-difluoro-1,4-phenylene; Z ¹¹ is a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, ethynylene, or tetrafluoroethylene; X ¹¹ is hydrogen or fluorine.)

In formula (1-1), ring A ^{11 which} is preferable for increasing the optical anisotropy of the compound is 1,4-phenylene or 2-fluoro-1,4-phenylene. The configuration of 1,4-cyclohexylene is preferably trans rather than cis for increasing the maximum temperature.
Desirable Z ¹¹ for increasing the optical anisotropy of the compound is a single bond or ethynylene.
In order to increase the dielectric anisotropy of the compound, X ¹¹ is preferably fluorine.

  At least one of liquid crystal compounds 1 is a compound represented by formula (1-1-3), a compound represented by formula (1-1-4), or a compound represented by formula (1-1-5) It is preferable that Further, at least two of the liquid crystal compounds 1 are represented by the compound represented by the formula (1-1-3) and the compound represented by the formula (1-1-5), or the formula (1-1-4). And a combination of the compound represented by formula (1-1-5).

（式（２）において、Ｒ^３は、炭素数１から１２のアルキル、炭素数１から１２のアルコキシ、または炭素数２から１２のアルケニルであり；環Ａ^３、Ａ^４およびＡ^５は独立して、１，４−シクロへキシレン、１，４−フェニレン、２−フルオロ−１，４−フェニレン、２，５−ジフルオロ−１，４−フェニレン、２，６−ジフルオロ−１，４−フェニレン、ピリジン−２，５−ジイル、ピリミジン−２，５−ジイル、１，３−ジオキサン−２，５−ジイル、またはテトラヒドロピラン−２，５−ジイルであり；Ｚ^３、Ｚ^４およびＺ^５は独立して、単結合、エチレン、ビニレン、メチレンオキシ、カルボニルオキシ、ジフルオロメチレンオキシ、エチニレン、またはテトラフルオロエチレンであり、Ｘ^４、Ｘ^５およびＸ^６は独立して、水素またはフッ素であるが、Ｘ^４およびＸ^５が同時にフッ素であることはなく；Ｙ^１はフッ素、塩素、少なくとも１つの水素がハロゲンで置き換えられた炭素数１から１２のアルキル、少なくとも１つの水素がハロゲンで置き換えられた炭素数１から１２のアルコキシ、または少なくとも１つの水素がハロゲンで置き換えられた炭素数２から１２のアルケニルであり；ｍは、０，１または２であり、ｍが２を表す場合、複数存在する環Ａ^４およびＺ^４は、それぞれ同じであっても、異なっていてもよい。） Examples of the liquid crystal compound 2 include a compound represented by the following formula (2).

(In the formula (2), R ³ is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons; rings A ³ , A ⁴ and A ⁵ are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, Pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl or tetrahydropyran-2,5-diyl; Z ³ , Z ⁴ and Z ⁵ are independently A single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy, ethynylene, or tetrafluoroethylene, and X ⁴ , X ^5, and X ⁶ are independently , Hydrogen or fluorine, but X ⁴ and X ⁵ are not simultaneously fluorine; Y ¹ is fluorine, chlorine, alkyl having 1 to 12 carbons in which at least one hydrogen is replaced by halogen, at least one 1 to 12 carbon alkoxy in which hydrogen is replaced by halogen, or alkenyl having 2 to 12 carbon in which at least one hydrogen is replaced by halogen; m is 0, 1 or 2, and m is 2 A plurality of the rings A ⁴ and Z ⁴ may be the same or different from each other.

  The configuration of 1,4-cyclohexylene is preferably trans rather than cis for increasing the maximum temperature.

Examples of the liquid crystal compound 2 include compounds represented by the following formulas (2-1) and (2-2) among the compounds represented by the formula (2). Among the compounds represented by the formula (2-1), compounds represented by the following formulas (2-1-1) to (2-1-13) are preferable.

(In Formula (2-1) and Formulas (2-1-1) to (2-1-13), R ³¹ is alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or 2 carbons. Ring A ³¹ is 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, pyrimidine- 2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; ring A ⁴¹ and ring A ⁵¹ are independently 1,4-phenylene, 2- fluoro-1,4-phenylene, or a ^{2,6-difluoro-1,4-phenylene;} Z ^{31, Z 41} and ^{Z 51} are independently a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, di Le Oro methyleneoxy, ethynylene, or ^{tetrafluoroethylene,} at least one of Z ^{31, Z 41} and ^{Z 51} is an ^{difluoromethyleneoxy; X 51} and ^{X 61} are each independently hydrogen or fluorine; Y ¹¹ is fluorine, chlorine, alkyl having 1 to 12 carbons in which at least one hydrogen is replaced with halogen, alkoxy having 1 to 12 carbons in which at least one hydrogen is replaced with halogen, or at least one hydrogen is halogen. And when m ¹ represents 0, 1 or 2, and when m ¹ represents 2, a plurality of rings A ⁴¹ and Z ⁴¹ are the same, May be different.)

であり、好ましくは

である。
化合物の誘電率異方性を上げるために好ましいＺ^３１、Ｚ^４１またはＺ^５１は、ジフルオロメチレンオキシであり、化合物の比抵抗を上げるために好ましいＺ^３１、Ｚ^４１またはＺ^５１は、単結合である。
化合物の誘電率異方性を上げるためまたはネマチック相の上限温度をあげるために好ましいｍ^１は、１である。
化合物の誘電率異方性を上げるために好ましいＸ^５１またはＸ^６１は、フッ素である。
化合物のネマチック相の下限温度を下げるために好ましいＹ^１１は、フッ素である。 In formula (2-1), ring A ^{31 that} is preferable for increasing the optical anisotropy of the compound is 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,6-difluoro-1,4. -Phenylene, and preferred ring A ⁴¹ or ring A ⁵¹ is 1,4-phenylene or 2-fluoro-1,4-phenylene. Tetrahydropyran-2,5-diyl is

And preferably

It is.
Z ³¹ , Z ⁴¹ or Z ^{51 which} is preferable for increasing the dielectric anisotropy of the compound is difluoromethyleneoxy, and Z ³¹ , Z ⁴¹ or Z ^{51 which} is preferable for increasing the specific resistance of the compound is a single bond. is there.
M ¹ is preferably ¹ for increasing the dielectric anisotropy of the compound or increasing the maximum temperature of the nematic phase.
Preferred X ⁵¹ or X ⁶¹ for increasing the dielectric anisotropy of the compound is fluorine.
Preferred Y ¹¹ for decreasing the minimum temperature of the nematic phase of the compound is fluorine.

  Among the liquid crystal compounds 2, at least one of the compounds represented by the formula (2-1) is a compound represented by the formula (2-1-2), a compound represented by the formula (2-1-5), a formula A compound represented by (2-1-6) or a compound represented by formula (2-1-10) is preferable. In addition, at least two of the compounds represented by the formula (2-1) in the liquid crystal compound 2 are a compound represented by the formula (2-1-2) and a compound represented by the formula (2-1-6). , A compound represented by formula (2-1-5) and a compound represented by formula (2-1-6), or a compound represented by formula (2-1-6) and formula (2-1-1) A combination of the compounds represented by 10) is preferred.

Of the compounds represented by the formula (2-2), compounds represented by the following formulas (2-2-1) to (2-2-12) are preferable.

であり、好ましくは

である。
化合物の比抵抗を上げるために好ましいＺ^３２、Ｚ^４２またはＺ^５２は、単結合である。
化合物の誘電率異方性を上げるため、または、ネマチック相の下限温度を下げるために好ましいｍ^２は、０である。
化合物の誘電率異方性を上げるために好ましいＸ^４２、Ｘ^５２またはＸ^６２は、フッ素である。
化合物のネマチック相の下限温度を下げるために好ましいＹ^１２は、フッ素である。
し In the formula (2-2) and the formulas (2-2-1) to (2-2-12), R ³² represents alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or 2 to carbons. Ring A ³² is 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2 , 5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran-2,5-diyl; ring A ⁴² and ring A ⁵² are independently 1,4-phenylene, 2-fluoro 1,4-phenylene or ^{2,6-difluoro-1,4-be-phenylene,;} Z ^{32, Z 42} and ^{Z 52} are independently a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, ethylene Len or be ^{tetrafluoroethylene,;} X ^{42, X 52} and ^{X 62} are independently hydrogen or ^fluorine, never ^{X 42} and ^{X 52} are simultaneously ^{fluorine; Y 12} is a fluorine, chlorine, at least 1 to 12 carbons alkyl in which one hydrogen is replaced with halogen, 1 to 12 carbons in which at least one hydrogen is replaced with halogen, or 2 carbons in which at least one hydrogen is replaced with halogen 12 is alkenyl; m ² is 0, 1 or 2, and when m ² represents 2, a plurality of rings A ⁴² and Z ⁴² may be the same or different; However, the compound represented by Formula (2-1) is excluded.
In formula (2-2), ring A ^{32 that} is preferable for increasing the optical anisotropy of the compound is 1,4-phenylene, 2-fluoro-1,4-phenylene, or 2,6-difluoro-1,4- Phenylene.
Preferred ring A ⁴² or ring A ⁵² in formula (2-2) is 1,4-phenylene or 2-fluoro-1,4-phenylene. Tetrahydropyran-2,5-diyl is

And preferably

It is.
Desirable Z ³² , Z ⁴² or Z ⁵² for increasing the specific resistance of the compound is a single bond.
M ² is preferably 0 for increasing the dielectric anisotropy of the compound or decreasing the minimum temperature of the nematic phase.
Desirable X ⁴² , X ⁵² or X ⁶² for increasing the dielectric anisotropy of the compound is fluorine.
Preferred Y ¹² for decreasing the minimum temperature of the nematic phase of the compound is fluorine.
Shi

  At least one of the compounds represented by the formula (2-2) in the liquid crystal compound 2 is a compound represented by the formula (2-2-4) or a compound represented by the formula (2-2-5). Preferably there is. In addition, at least two of the compounds represented by the formula (2-2) in the liquid crystal compound 2 are a compound represented by the formula (2-2-4) and a compound represented by the formula (2-2-5). It is preferable that it is the combination of these.

（式（３）において、Ｒ^４およびＲ^５は独立して、炭素数１から１２のアルキル、炭素数１から１２のアルコキシ、または炭素数２から１２のアルケニルであり；環Ａ^６または環Ａ^７は独立して、１，４−シクロへキシレン、１，４−フェニレン、２−フルオロ−１，４−フェニレン、２，５−ジフルオロ−１，４−フェニレン、または２，６−ジフルオロ−１，４−フェニレンであり；Ｚ^６は、単結合、エチレン、ビニレン、メチレンオキシ、カルボニルオキシ、ジフルオロメチレンオキシ、エチニレン、またはテトラフルオロエチレンであり；Ｚ^７は、単結合、エチレン、ビニレン、メチレンオキシ、カルボニルオキシ、ジフルオロメチレンオキシ、またはテトラフルオロエチレンであり；ｎは、０、１または２であり、ｎが２を表す場合、複数存在する環Ａ^７およびＺ^７は、それぞれ同じであっても、異なっていてもよく；ただし、式（１−１）で表される化合物は除く。） Examples of the liquid crystal compound 3 include a compound represented by the following formula (3).

(In Formula (3), R ⁴ and R ⁵ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons; ring A ⁶ or ring A ⁷ is independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, or 2,6-difluoro-1 , it is a 4-phenylene; Z ⁶ is a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy be ethynylene or tetrafluoroethylene,; Z ⁷ is a single bond, ethylene, vinylene, methyleneoxy , Carbonyloxy, difluoromethyleneoxy or tetrafluoroethylene; n is 0, 1 or 2; If, ring A ^7, and Z ⁷ there is a plurality, even in each same or different; provided that the compound represented by formula (1-1) is excluded).

In formula (3), preferred ring A ⁶ and ring A ⁷ for increasing the optical anisotropy of the compound are 1,4-phenylene or 2-fluoro-1,4-phenylene.
Preferred Z ⁶ for increasing the optical anisotropy of the compound is a single bond or ethynylene, and preferred Z ⁷ for increasing the optical anisotropy of the compound is a single bond.
Desirable n is 0 for decreasing the minimum temperature of the nematic phase of the compound.

式（３−１）〜（３−１２）において、Ｒ^４およびＲ^５は独立して、炭素数１から１２のアルキル、炭素数１から１２のアルコキシ、または炭素数２から１２のアルケニルである。 As the liquid crystal compound 3, among the compounds represented by the formula (3), compounds represented by the following formulas (3-1) to (3-12) are preferable.

In formulas (3-1) to (3-12), R ⁴ and R ⁵ are each independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons. .

  Among the liquid crystal compounds 3, at least one of the compounds represented by the formula (3) is a compound represented by the formula (3-2), a compound represented by the formula (3-3), and a formula (3-8). The compound represented by formula (3-9) or the compound represented by formula (3-12) is preferred. In addition, at least two of the compounds represented by the formula (3) among the liquid crystal compounds 3 are a compound represented by the formula (3-3) and a compound represented by the formula (3-8), or the formula (3 It is preferable that it is a combination of the compound represented by -3) and the compound represented by Formula (3-12).

（式（４）において、Ｒ^６およびＲ^７は独立して、炭素数１から１２のアルキル、炭素数１から１２のアルコキシ、炭素数２から１２のアルケニル、炭素数２から１２のアルケニルオキシ、または少なくとも１つの水素がフッ素または塩素で置き換えられた炭素数１から１２のアルキルであり；環Ａ^８およびＡ^１０は独立して、１，４−シクロへキシレン、１，４−シクロへキセニレン、テトラヒドロピラン−２，５−ジイル、１，４−フェニレン、少なくとも１つの水素がフッ素または塩素で置き換えられた１，４−フェニレン、ナフタレン−２，６−ジイル、少なくとも１つの水素がフッ素または塩素で置き換えられたナフタレン−２，６−ジイル、クロマン−２，６−ジイル、または少なくとも１つの水素がフッ素または塩素で置き換えられたクロマン−２，６−ジイルであり；環Ａ^９は、２，３−ジフルオロ−１，４−フェニレン、２−クロロ−３−フルオロ−１，４−フェニレン、２，３−ジフルオロ−５−メチル−１，４−フェニレン、３，４，５−トリフルオロナフタレン−２，６−ジイル、または７，８−ジフルオロクロマン−２，６−ジイルであり；Ｚ^８およびＺ^９は独立して、単結合、エチレン、カルボニルオキシ、またはメチレンオキシであり；ｏは、１、２、または３であり；ｐは、０または１であり；ｏとｐとの和は３以下である。） Examples of the liquid crystal compound 4 include a compound represented by the following formula (4).

(In Formula (4), R ⁶ and R ⁷ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, alkenyloxy having 2 to 12 carbons, Or alkyl having 1 to 12 carbon atoms in which at least one hydrogen is replaced by fluorine or chlorine; rings A ⁸ and A ¹⁰ are independently 1,4-cyclohexylene, 1,4-cyclohexenylene, Tetrahydropyran-2,5-diyl, 1,4-phenylene, 1,4-phenylene in which at least one hydrogen is replaced by fluorine or chlorine, naphthalene-2,6-diyl, at least one hydrogen is fluorine or chlorine Replaced naphthalene-2,6-diyl, chroman-2,6-diyl, or at least one hydrogen is replaced by fluorine or chlorine Substituted Chroman-2,6-diyl; ring A ⁹ 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; Z ⁸ and Z ⁹ are independently A single bond, ethylene, carbonyloxy, or methyleneoxy; o is 1, 2, or 3; p is 0 or 1; and the sum of o and p is 3 or less.)

As the liquid crystal compound 4, among the compounds represented by the formula (4), compounds represented by the following formulas (4-1) to (4-22) are preferable.

(In the formulas (4-1) to (4-22), R ⁶¹ and R ⁷¹ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, alkenyl having 2 to 12 carbons, C2-C12 alkenyloxy or C1-C12 alkyl in which at least one hydrogen is replaced by fluorine or chlorine.

  Among the liquid crystal compounds 4, at least one of the compounds represented by the formula (4) is a compound represented by the formula (4-1), a compound represented by the formula (4-4), and a formula (4-6). The compound represented by formula (4-8), the compound represented by formula (4-9), or the compound represented by formula (4-10) is preferred. In addition, at least two of the compounds represented by the formula (4) among the liquid crystal compounds 4 are a compound represented by the formula (4-1), a compound represented by the formula (4-6), and a formula (4-1). ) And a compound represented by formula (4-8), a compound represented by formula (4-4) and formula (4-9), or a formula (4-4) A combination of the compound and the compound represented by formula (4-10) is preferable.

  In the present specification, preferred alkyl is methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, or octyl. More desirable alkyl is ethyl, propyl, butyl, pentyl, or heptyl for decreasing the viscosity.

  In the present specification, preferred alkoxy is methoxy, ethoxy, propoxy, butoxy, pentyloxy, hexyloxy, or heptyloxy. More desirable alkoxy is methoxy or ethoxy for decreasing the viscosity.

  In the present specification, preferred alkenyl is 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. More desirable alkenyl is vinyl, 1-propenyl, 3-butenyl, or 3-pentenyl for decreasing the viscosity. The preferred configuration of —CH═CH— in these alkenyls depends on the position of the double bond. Trans is preferable in alkenyl such as 1-propenyl, 1-butenyl, 1-pentenyl, 1-hexenyl, 3-pentenyl and 3-hexenyl for decreasing the viscosity. Cis is preferable in alkenyl such as 2-butenyl, 2-pentenyl and 2-hexenyl. In these alkenyl, linear alkenyl is preferable to branching.

  The content of the liquid crystal composition in the liquid crystal capsule of the present invention is preferably 50 to 90% by weight and more preferably 55 to 80% by weight with respect to the total amount of the liquid crystal capsule. When the amount is within the above range, sufficient liquid crystal performance can be obtained, and the capsule wall has a sufficient relative thickness and is not easily destroyed.

(2) Optically active compound The liquid crystal composition may contain an optically active compound for the purpose of inducing a helical structure of the liquid crystal to give a twist angle. Examples of such optically active compounds include compounds represented by formulas (5-1) to (5-5).

  These optically active compounds may be one compound or a combination of two or more compounds. The optically active compound is preferably contained in an amount of about 5% by weight or less, more preferably about 0.01% by weight to about 2% by weight, based on the total weight of the liquid crystal composition.

(3) Antioxidant A large voltage not only at room temperature but also at a temperature close to the upper limit temperature of the nematic phase after the device has been used for a long time to prevent a decrease in specific resistance of the liquid crystal composition due to heating in the atmosphere. In order to maintain the retention rate, the liquid crystal composition may contain an antioxidant. Preferable examples of the antioxidant include compounds represented by the following formula (6) (wherein t is an integer of 1 to 9).

Preferred t in the formula (6) is 1, 3, 5, 7, or 9. Further preferred t is 7. The compound represented by the formula (6) in which t is 7 has low volatility, so that a large voltage holding ratio is maintained not only at room temperature but also at a temperature close to the upper limit temperature of the nematic phase after using the device for a long time. It is effective to do.
A desirable ratio of the antioxidant in the liquid crystal composition is about 50 ppm or more for obtaining the effect thereof, and is about 600 ppm or less so as not to lower the maximum temperature of the nematic phase or increase the minimum temperature of the nematic phase. It is. A more desirable ratio is in the range of approximately 100 ppm to approximately 300 ppm.

(4) Ultraviolet absorber The liquid crystal composition may contain an ultraviolet absorber. Preferred examples of the ultraviolet absorber include benzophenone derivatives, benzoate derivatives, triazole derivatives and the like. Also preferred are light stabilizers such as sterically hindered amines. A desirable ratio in these absorbents and stabilizers is about 50 ppm or more for obtaining the effect thereof, and about 10,000 ppm or less for avoiding a decrease in the maximum temperature of the nematic phase or preventing an increase in the minimum temperature of the nematic phase. It is. A more desirable ratio is in the range of approximately 100 ppm to approximately 10,000 ppm.

(5) Dichroic dye The liquid crystal composition may contain a dichroic dye such as an azo dye or an anthraquinone dye in order to adapt to a GH (guest host) mode device, for example. . A desirable ratio of the dichroic dye contained in the liquid crystal composition is in the range of approximately 0.01% by weight to approximately 10% by weight.
In order to prevent foaming of the liquid crystal composition, an antifoaming agent such as dimethyl silicone oil or methylphenyl silicone oil may be further added to the liquid crystal composition. A desirable ratio of the antifoaming agent is approximately 1 ppm or more for obtaining the effect thereof, and approximately 1000 ppm or less for preventing a display defect. A more desirable ratio is in the range of approximately 1 ppm to approximately 500 ppm.

2-2. Nanoemulsion preparation process (process B)
The microemulsion is charged into an apparatus such as a nanovaiter (pressure 150 MPa, for example, 7 passes) to form a nanosize emulsion (nanoemulsion).

As an emulsifying device, a device such as a stirring type homogenizer is used for preparing a microemulsion, and a device such as a high-pressure nanometer, starburst or microfluidizer is used for preparing a nanoemulsion.
There are two types of homogenizers: an ultrasonic type that causes cavitation by ultrasonic waves to make particles fine, an agitation type that makes particles by stirring, and a high pressure type that makes particles fine by applying pressure. The ultrasonic method causes cavitation by applying ultrasonic vibration in a liquid to make particles fine, so that the emulsifying ability is high, but the processing amount is small. The agitation method is suitable for processing that does not require relatively high accuracy because it is agitated at high speed to atomize. It is often used in the stage before full-scale emulsification. Since the high-pressure type is finely divided by applying pressure, the processing amount is large and miniaturization is possible as compared with other apparatuses. The high-pressure type includes a nozzle type and a valve type, and the nozzle type is refined by passing particles through pores (nozzles) under high pressure. There is a disadvantage that the nozzle is clogged. In the valve type, particles in the liquid are refined by applying high pressure and passing through a homovalve. This method can also handle high viscosity products that can become clogged.
The number of passes when using a high-pressure homogenizer is preferably 3 to 10 times and more preferably 3 to 6 times in order to make the emulsion size distribution uniform and to avoid liquid crystal leakage.

2-3. Capsule wall construction process using in-situ polymerization method (process C)
The monomer or prepolymer is placed so as to surround the liquid crystal composition and the surfactant by introducing the monomer or prepolymer that is the raw material of the capsule wall into the mixture containing the O / W type nanoemulsion obtained in step B. The monomer wall or the prepolymer is polymerized to form a capsule wall.
Below, the monomer used as a capsule wall is demonstrated.

2-3-1. Capsule Wall The monomer and prepolymer used in the method for producing a liquid crystal capsule of the present invention are materials for the capsule wall of the liquid crystal capsule. That is, by an in-situ polymerization method, the monomer and the prepolymer are polymerized so as to enclose the liquid crystal composition, thereby forming a closed curved capsule wall. The monomer and prepolymer of the present invention are not particularly limited as long as they have a polymerization group.

  As a monomer or prepolymer used for the capsule wall in the method for producing a liquid crystal capsule of the present invention, for example, gelatin, amide resin, urethane resin, silicone resin, phenol resin, urea resin, melamine resin, melamine / phenol resin, polyester resin, Examples include diallyl phthalate resin and epoxy resin. As the capsule wall used in the method for producing a liquid crystal capsule of the present invention, it is preferable to use a melamine resin or a urea-formalin resin. A more preferred capsule wall is melamine resin.

The content of the capsule wall is preferably 1 to 60% by weight, more preferably 5 to 45% by weight, based on the liquid crystal composition.

  The invention is explained in more detail by means of examples. The invention is not limited by these examples. The invention also includes a mixture of at least two of the example compositions. The synthesized compound was identified by a method such as NMR analysis. The properties of the compound, composition and processed product were measured by the methods described below.

NMR analysis: For measurement, DRX-500 manufactured by Bruker BioSpin Corporation was used. ^In the measurement of ¹ H-NMR, the sample was dissolved in a deuterated solvent such as CDCl _3, and the measurement was performed at room temperature under conditions of 500 MHz and 16 integrations. Tetramethylsilane was used as an internal standard. ^{For 19} F-NMR measurement, CFCl ₃ was used as an internal standard, and the number of integrations was 24. In the description of the nuclear magnetic resonance spectrum, s is a singlet, d is a doublet, t is a triplet, q is a quartet, quint is a quintet, sex is a sextet, m is a multiplet, and br is broad.

  Gas chromatographic analysis: A GC-14B gas chromatograph manufactured by Shimadzu Corporation was used for measurement. The carrier gas is helium (2 mL / min). The sample vaporization chamber was set at 280 ° C, and the detector (FID) was set at 300 ° C. For separation of the component compounds, capillary column DB-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm; stationary liquid phase is dimethylpolysiloxane; nonpolar) manufactured by Agilent Technologies Inc. was used. The column was held at 200 ° C. for 2 minutes and then heated to 280 ° C. at a rate of 5 ° C./min. A sample was prepared in an acetone solution (0.1% by weight), and 1 μL thereof was injected into the sample vaporization chamber. The recorder is a C-R5A type Chromatopac manufactured by Shimadzu Corporation or an equivalent thereof. The obtained gas chromatogram showed the peak retention time and peak area corresponding to the component compounds.

  As a solvent for diluting the sample, chloroform, hexane or the like may be used. In order to separate the component compounds, the following capillary column may be used. HP-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm) manufactured by Agilent Technologies Inc., Rtx-1 (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm) manufactured by Restek Corporation, BP-1 made by SGE International Pty. Ltd (length 30 m, inner diameter 0.32 mm, film thickness 0.25 μm). In order to prevent compound peaks from overlapping, a capillary column CBP1-M50-025 (length 50 m, inner diameter 0.25 mm, film thickness 0.25 μm) manufactured by Shimadzu Corporation may be used.

  The ratio of the liquid crystal compound contained in the composition may be calculated by the following method. A mixture of liquid crystal compounds is detected by a gas chromatograph (FID). The area ratio of peaks in the gas chromatogram corresponds to the ratio (weight ratio) of liquid crystal compounds. When the capillary column described above is used, the correction coefficient of each liquid crystal compound may be regarded as 1. Therefore, the ratio (% by weight) of the liquid crystal compound can be calculated from the peak area ratio.

  Measurement sample: When measuring the characteristics of the composition, the composition was used as it was as a sample. When measuring the characteristics of the compound, a sample for measurement was prepared by mixing this compound (15% by weight) with mother liquid crystals (85% by weight). The characteristic value of the compound was calculated from the value obtained by the measurement by extrapolation. (Extrapolated value) = {(Measured value of sample) −0.85 × (Measured value of mother liquid crystal)} / 0.15. When the smectic phase (or crystal) is precipitated at 25 ° C. at this ratio, the ratio of the compound and the mother liquid crystal is 10% by weight: 90% by weight, 5% by weight: 95% by weight, 1% by weight: 99% by weight in this order changed. By this extrapolation method, the maximum temperature, optical anisotropy, viscosity, and dielectric anisotropy values for the compound were determined.

The following mother liquid crystals were used. The ratio of the component compounds is shown by weight%.

  Measuring method: The characteristics were measured by the following method. Many of these methods are modified by a method described in the JEITA standard (JEITA ED-2521B) established by the Japan Electronics and Information Technology Industries Association (JEITA), or a modification thereof. Was the way. No thin film transistor (TFT) was attached to the TN device used for the measurement.

(1) Maximum temperature of nematic phase (NI; ° C.): A sample was placed on a hot plate of a melting point measuring apparatus equipped with a polarizing microscope and heated at a rate of 1 ° C./min. The temperature was measured when a part of the sample changed from a nematic phase to an isotropic liquid.

(2) Minimum Temperature of a Nematic Phase _{(T C;} ° C.): A sample having a nematic phase was put in a glass bottle, 0 ℃, -10 ℃, -20 ℃, -30 ℃, and -40 ℃ for 10 days in a freezer After storage, the liquid crystal phase was observed. For example, when the sample remained in a nematic phase at −20 ° C. and changed to a crystal or smectic phase at −30 ° C., T _C <−20 ° C. was described.

(3) Viscosity (bulk viscosity; η; measured at 20 ° C .; mPa · s): An E-type viscometer manufactured by Tokyo Keiki Co., Ltd. was used for the measurement.

(4) Viscosity (rotational viscosity; γ1; measured at 20 ° C .; mPa · s): The measurement was performed according to the method described in M. Imai et al., Molecular Crystals and Liquid Crystals, Vol. 259, 37 (1995). I followed. A sample was put in a TN device having a twist angle of 0 ° and a distance (cell gap) between two glass substrates of 5 μm. A voltage was applied to this device in steps of 0.5 V in the range of 16 V to 19.5 V. After no application for 0.2 seconds, the application was repeated under the condition of only one rectangular wave (rectangular pulse; 0.2 seconds) and no application (2 seconds). The peak current and peak time of the transient current generated by this application were measured. The value of rotational viscosity was obtained from these measured values and the calculation formula (8) described on page 40 in the paper by M. Imai et al. The value of dielectric anisotropy necessary for this calculation was determined by the method described below using the element whose rotational viscosity was measured.

(5) Optical anisotropy (refractive index anisotropy; Δn; measured at 25 ° C.): Measurement was performed with an Abbe refractometer using a light having a wavelength of 589 nm and a polarizing plate attached to an eyepiece. After rubbing the surface of the main prism in one direction, the sample was dropped on the main prism. The refractive index n‖ was measured when the polarization direction was parallel to the rubbing direction. The refractive index n⊥ was measured when the polarization direction was perpendicular to the rubbing direction. The value of optical anisotropy was calculated from the equation: Δn = n∥−n⊥. In the mode using the optical change due to the Kerr effect, it is desirable that the product of the optical anisotropy and the dielectric anisotropy is large. Therefore, the optical anisotropy is preferably as large as possible. The optical anisotropy is preferably in the range of 0.20 to 0.35, and more preferably in the range of 0.23 to 0.32.

(6) Dielectric anisotropy (Δε; measured at 25 ° C.): A sample was put in a TN device in which the distance between two glass substrates (cell gap) was 9 μm and the twist angle was 80 degrees. Sine waves (10 V, 1 kHz) were applied to the device, and after 2 seconds, the dielectric constant (ε‖) in the major axis direction of the liquid crystal molecules was measured. Sine waves (0.5 V, 1 kHz) were applied to the device, and after 2 seconds, the dielectric constant (ε⊥) in the minor axis direction of the liquid crystal molecules was measured. The value of dielectric anisotropy was calculated from the equation: Δε = ε∥−ε⊥.
A larger dielectric anisotropy is desirable to reduce the driving voltage. In particular, in a mode in which the electric field applied to the liquid crystal composition is limited due to stabilization of the polymer or encapsulation, the driving voltage tends to be high, so that the dielectric anisotropy is preferably as large as possible. In the mode using the optical change due to the Kerr effect, it is desirable that the product of the optical anisotropy and the dielectric anisotropy is large. Therefore, the dielectric anisotropy is preferably as large as possible. The dielectric anisotropy is preferably in the range of 8 to 40, more preferably in the range of 10 to 30.

(7) Threshold voltage (Vth; measured at 25 ° C .; V): An LCD5100 luminance meter manufactured by Otsuka Electronics Co., Ltd. was used for the measurement. The light source was a halogen lamp. A sample was put in a normally white mode TN device in which the distance between two glass substrates (cell gap) was 0.45 / Δn (μm) and the twist angle was 80 degrees. The voltage (32 Hz, rectangular wave) applied to this element was increased stepwise from 0V to 10V by 0.02V. At this time, the device was irradiated with light from the vertical direction, and the amount of light transmitted through the device was measured. A voltage-transmittance curve was created in which the transmittance was 100% when the light amount reached the maximum and the transmittance was 0% when the light amount was the minimum. The threshold voltage was expressed as a voltage when the transmittance reached 90%.

(8) Elastic constant (K; measured at 25 ° C .; pN): An HP4284A LCR meter manufactured by Yokogawa-Hewlett-Packard Co., Ltd. was used for the measurement. A sample was put in a horizontal alignment element in which the distance between two glass substrates (cell gap) was 20 μm. A charge of 0 to 20 volts was applied to the device, and the capacitance and applied voltage were measured. Fitting the measured values of capacitance (C) and applied voltage (V) using “Liquid Crystal Device Handbook” (Nikkan Kogyo Shimbun), page 75, formula (2.98), formula (2.101) Thus, the values of K11 and K33 were obtained from the formula (2.99). Next, K22 was calculated from the equation (3.18) on page 171 using the values of K11 and K33 obtained earlier. The elastic constant was expressed as an average value of K11, K22, and K33 thus determined.

(9) Specific resistance (ρ; measured at 25 ° C .; Ωcm): 1.0 mL of a sample was injected into a container equipped with electrodes. A DC voltage (10 V) was applied to the container, and the DC current after 10 seconds was measured. The specific resistance was calculated from the following equation. (Resistivity) = {(Voltage) × (Capacity of container)} / {(DC current) × (Dielectric constant of vacuum)}.

(10) SEM (scanning electron microscope) observation: Capsule slurry is coated on high-quality neutral paper or glass using a die coater, spin coater or bar coater, and capsule slurry using a hot plate or dryer The sample was prepared by evaporating the water inside. The sample was fixed to a sample stage for SEM observation with a conductive tape, and platinum was deposited using a sputtering apparatus (manufactured by Hitachi High-Technologies Corporation: E-1045). This sample stage was attached to SEM (manufactured by Hitachi High-Technologies Corporation: SU-70). The sample was observed while changing the acceleration voltage (0.5 to 1.0 kV), magnification (1 k to 50 k), and the like.

(11) Measurement of average particle size of capsule: Nikkiso Dynamic Light Scattering Particle Size Analyzer (Nanotrack UPA) was used for measurement. A sample was prepared by diluting the capsule slurry with ultrapure water to an appropriate concentration, and the average particle size was measured at 25 ° C.

  The compounds in Examples were represented by symbols based on the definitions in Table 2 below. In Table 2, the configuration regarding 1,4-cyclohexylene is trans. The number in parentheses after the symbol corresponds to the compound number. The symbol (−) means other liquid crystal compounds. The ratio (percentage) of the liquid crystal compound is a weight percentage (% by weight) based on the weight of the liquid crystal composition. Finally, the characteristic values of the composition are summarized.

The composition and physical property values of the liquid crystal compositions a to c used in Examples or Comparative Examples are as follows.
[Liquid crystal composition a]
3-BB (F, F) XB (F, F) -F (2-1-2) 21%
3-HBB-F (2-2) 3%
5-HHB-F (2-2) 2%
3-HBB (F, F) -F (2-2) 12%
3-HHBB (F, F) -F (2-2) 6%
3-HHB-1 (3) 7%
V-HHB-1 (3) 12%
3-HH-VFF (-) 31%
3-HHXB (F, F) -F (-) 6%
NI = 77.9 ° C .; Tc <−30 ° C .; Δn = 0.099; Δε = 7.4; Vth = 1.38 V; η = 15.1 mPa · s.

[Liquid crystal composition b]
3-HB (F) TB-2 (1-1-3) 5%
3-HB (F) TB-3 (1-1-3) 5%
3-HB (F) TB-4 (1-1-3) 5%
3-H2BTB-2 (1-1-5) 3%
3-H2BTB-3 (1-1-5) 3%
3-H2BTB-4 (1-1-5) 3%
3-BB (F, F) XB (F, F) -F (2-1-2) 9%
3-BB (F) B (F, F) XB (F) -F (2-1-5) 3%
3-BB (F) B (F, F) XB (F, F) -F
(2-1-6) 2%
4-BB (F) B (F, F) XB (F, F) -F
(2-1-6) 7%
5-BB (F) B (F, F) XB (F, F) -F
(2-1-6) 7%
3-BB (F, F) XB (F) B (F, F) -F
(2-1-10) 6%
3-BB (F) B (F, F) -F (2-2-4) 3%
2-BTB-O1 (3-3) 7.8%
3-BTB-O1 (3-3) 7.8%
4-BTB-O1 (3-3) 7.8%
4-BTB-O2 (3-3) 7.8%
5-BTB-O1 (3-3) 7.8%
NI = 90.0 ° C .; Tc <−20 ° C .; Δn = 0.246; Δε = 9.4; Vth = 1.88 V; η = 42.7 mPa · s.

[Liquid crystal composition c]
3-HB-O2 (3-1) 2%
1-BB-3 (3-2) 9%
5-B (F) BB-2 (3-7) 2%
3-BB (2F, 3F) -O2 (4-4) 9%
5-BB (2F, 3F) -O2 (4-4) 5%
2-HH1OB (2F, 3F) -O2 (4-8) 12%
3-HH1OB (2F, 3F) -O2 (4-8) 21%
2-HH-3 (-) 21%
3-HH-4 (-) 12%
3-HHB-1 (-) 4%
3-HHB-O1 (-) 3%

[Comparative Example 1]
(Step A) A 5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (120 g) was placed in a stainless beaker and stirred with a homogenizer (IKAT25). Thereto, liquid crystal composition a (80 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (20 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a microcapsule slurry.
When a small amount of microcapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM), and microcapsules having an average particle size of about 2.5 μm were confirmed.

[Comparative Example 2]
(Step A) A 5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (120 g) was placed in a stainless beaker and stirred with a homogenizer (IKAT25). Thereto, liquid crystal composition b (80 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (20 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a microcapsule slurry.
When a small amount of microcapsule slurry was applied to high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM), and microcapsules having an average particle diameter of about 3.5 μm were confirmed.

[Example 1]
(Step A) A 5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (60 g) and ultrapure water (100 g) were placed in a stainless steel beaker and stirred with a homogenizer (IKAT25). Thereto, liquid crystal composition b (40 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (161.2 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass through it 5 times at an extrusion pressure of 150 MPa. Further, an 8.7 wt% styrene maleic anhydride copolymer (SMA) aqueous solution (46.7 g) was added. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (8.5 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM), and nanocapsules having an average particle diameter of about 250 nm were confirmed.

[Example 2]
(Step A) An aqueous solution (160 g) of 5.24 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) and ultrapure water (70 g) were placed in a stainless steel beaker and stirred with a homogenizer (IKAT25). Thereto, liquid crystal composition b (40 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (226.6 g) was charged into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and passed three times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (8.4 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM). As a result, nanocapsules having an average particle diameter of about 200 nm were confirmed.

[Example 3]
(Step A) A 5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (60 g) and ultrapure water (100 g) were placed in a stainless steel beaker and stirred with a homogenizer (IKAT25). Thereto, liquid crystal composition b (40 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (173.6 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass through it 5 times at an extrusion pressure of 150 MPa. Further, an 8.7 wt% aqueous styrene maleic anhydride copolymer (SMA) solution (117.3 g) was added. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (8.7 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM), and nanocapsules having an average particle diameter of about 250 nm were confirmed.

[Example 4]
(Step A) A 5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (100 g) and ultrapure water (60 g) were placed in a stainless steel beaker and stirred with a homogenizer (IKAT25). Thereto, liquid crystal composition b (40 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (105.6 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (5.3 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was applied to a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM). As a result, nanocapsules having an average particle diameter of about 300 nm were confirmed.

[Example 5]
(Step A) A 5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (100 g) and ultrapure water (60 g) were placed in a stainless steel beaker and stirred with a homogenizer (IKAT25). Thereto, liquid crystal composition b (40 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) The emulsion (100.0 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass 5 times at an extrusion pressure of 150 MPa. Further, an 8.7 wt% styrene maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (40 g) was added. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (5 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on fine neutral paper and dried, the result was observed with a scanning electron microscope (SEM). As a result, nanocapsules having an average particle diameter of about 150 nm were confirmed.

[Example 6]
(Step A) A 9.5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (78.9 g) was placed in a stainless beaker and stirred with a stirrer (made by HEIDON: high power general purpose stirrer BLh1200). However, the liquid crystal composition b (60 g) was added at 1 ml / min. Then, ultrapure water (161.1 g) was added dropwise while preparing an emulsion. (Step B) The emulsion (200.0 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass through it 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (10 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM), and nanocapsules having an average particle diameter of about 250 nm were confirmed.

[Example 7]
(Step A) A 9.5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (78.9 g) was placed in a stainless beaker and stirred with a stirrer (made by HEIDON: high power general purpose stirrer BLh1200). However, the liquid crystal composition b (90 g) was added at 1 ml / min. Then, ultrapure water (161.1 g) was added dropwise while preparing an emulsion. (Step B) The emulsion (200.0 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass through it 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (15 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM). As a result, nanocapsules having an average particle diameter of about 200 nm were confirmed.

[Example 8]
(Step A) A 9.5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (78.9 g) was placed in a stainless beaker and stirred with a stirrer (made by HEIDON: high power general purpose stirrer BLh1200). However, the liquid crystal composition b (90 g) was added at 1 ml / min. Then, ultrapure water (161.1 g) was added dropwise while preparing an emulsion. (Step B) The emulsion (200.0 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass through it 5 times at an extrusion pressure of 150 MPa. Further, an aqueous solution (33 g) of 14.7 wt% styrene maleic anhydride copolymer (molecular weight: about 350,000) was added. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (13.7 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM). As a result, nanocapsules having an average particle diameter of about 200 nm were confirmed.

[Example 9]
(Step A) A 9.5 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (78.9 g) was placed in a stainless beaker and stirred with a stirrer (made by HEIDON: high power general purpose stirrer BLh1200). However, the liquid crystal composition b (75 g) was added at 1 ml / min. Then, ultrapure water (161.1 g) was added dropwise while preparing an emulsion. (Step B) The emulsion (200.0 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass through it 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 80 ° C., and the melamine prepolymer (11.9) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200) and stirred for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM). As a result, nanocapsules having an average particle diameter of about 200 nm were confirmed.

[Example 10]
(Step A) A 9.5 wt% partially methyl esterified styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (189.5 g) was placed in a stainless beaker, and a stirrer (manufactured by HEIDON: high power general purpose stirrer) The liquid crystal composition b (90 g) was stirred at 1 ml / min. After adding dropwise at a rate of 1, ultrapure water was added dropwise to prepare an emulsion. (Step B) The emulsion (240.0 g) was put into Nanovaita (Yoshida Kikai Kogyo Co., Ltd .: NVL-ES008-D) and allowed to pass through it 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (9 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
When a small amount of nanocapsule slurry was coated on a high-quality neutral paper and dried, it was observed with a scanning electron microscope (SEM), and nanocapsules having an average particle diameter of about 250 nm were confirmed.

[Example 11]
(Step A) A 6.0 wt% aqueous styrene-maleic anhydride copolymer (molecular weight of about 350,000) aqueous solution (331.6 g) and ultrapure water (243.4 g) were placed in a stainless steel beaker and homogenizer (IKAT25). Stir. Thereto, liquid crystal composition b (80 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (240.2 g) was charged into Starburst (Sugino Machine Co., Ltd .: HJP-25001) and allowed to pass 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 70 ° C., and melamine prepolymer (7.4 g) was added while stirring with a stirrer (manufactured by HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle size of about 320 nm were confirmed. It was.

[Example 12]
(Step A) A 6.0 wt% aqueous styrene-maleic anhydride copolymer (molecular weight of about 350,000) aqueous solution (331.6 g) and ultrapure water (243.4 g) were placed in a stainless steel beaker and homogenizer (IKAT25). Stir. Thereto, liquid crystal composition b (80 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (240.4 g) was charged into Starburst (Sugino Machine: HJP-25001) and allowed to pass 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (9.8 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed with a dynamic scattering particle size analyzer (Nanotrac UPA) manufactured by Nikkiso. As a result, nanocapsules with an average particle size of about 270 nm were confirmed. It was.

[Example 13]
(Step A) A 6.0 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (139.7 g) and ultrapure water (28.0 g) were placed in a stainless steel beaker, and homogenizer (IKAT25). Stir. Thereto, liquid crystal composition b (40 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (187.6 g) was charged into Starburst (Sugino Machine Co., Ltd .: HJP-25001) and passed three times at an extrusion pressure of 200 MPa. (Step C) Thereafter, the mixture was heated to 80 ° C., and melamine prepolymer (9.0 g) was added while stirring with a stirrer (manufactured by HEIDON: high-power general-purpose stirrer BLh1200), followed by stirring for 2 hours. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle diameter of about 310 nm were confirmed. It was.

[Example 14]
(Step A) A 11.8 wt% styrene-maleic anhydride copolymer (molecular weight: about 350,000) aqueous solution (52.8 g) and ultrapure water (155.3 g) were placed in a stainless steel beaker and homogenizer (IKAT25). Stir. Thereto, liquid crystal composition b (30 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (185.3 g) was put into a starburst (Sugino Machine Co., Ltd .: HJP-25001) and allowed to pass five times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 70 ° C., and melamine prepolymer (5.8 g) was added while stirring with a stirrer (made by HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle diameter of about 310 nm were confirmed. It was.

[Example 15]
(Step A) An aqueous solution (115.1 g) of 14.6 wt% styrene-maleic anhydride copolymer (molecular weight of about 5,500) and ultrapure water (220.3 g) were placed in a stainless steel beaker and homogenizer (IKAT25). And stirred. Thereto, liquid crystal composition b (67.1 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (180 g) was put into a starburst (Sugino Machine Co., Ltd .: HJP-25001) and passed three times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 70 ° C., and melamine prepolymer (12.0 g) was added while stirring with a stirrer (manufactured by HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 10 wt% aqueous sodium hydroxide solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle diameter of about 140 nm were confirmed. It was.

[Example 16]
(Step A) An aqueous solution (91.4 g) of 10.2 wt% styrene-maleic anhydride copolymer (molecular weight about 5,500) and ultrapure water (95.3 g) were placed in a stainless steel beaker and homogenizer (IKAT25). And stirred. Thereto, liquid crystal composition b (28 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (90.4 g) was charged into Starburst (Sugino Machine: HJP-25001) and passed three times at an extrusion pressure of 150 MPa. (Step C) Then, the mixture was heated to 70 ° C., and melamine prepolymer (3.0 g) was added while stirring with a stirrer (manufactured by HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 1.0 wt% aqueous ammonia solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle size of about 120 nm were confirmed. It was.

[Example 17]
(Step A) A 11.8 wt% styrene-maleic anhydride copolymer (molecular weight: about 7,500) aqueous solution (39.7 g) and ultrapure water (53.7 g) were placed in a stainless beaker and homogenizer (IKAT25). And stirred. Thereto, liquid crystal composition b (14 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (90.4 g) was charged into Starburst (Sugino Machine: HJP-25001) and passed three times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 70 ° C., and melamine prepolymer (4.9 g) was added while stirring with a stirrer (manufactured by HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrac UPA) manufactured by Nikkiso. Nanocapsules with an average particle diameter of about 70 nm were confirmed. It was.

[Example 18]
(Step A) A 6.7 wt% 1-octadecene-maleic anhydride copolymer (molecular weight: about 36,000) aqueous solution (111.8 g) and ultrapure water (13 g) were placed in a stainless steel beaker and homogenizer (IKAT25). And stirred. Thereto, liquid crystal composition b (30 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (135.5 g) was put into Starburst (Sugino Machine: HJP-25001) and allowed to pass 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 70 ° C., and melamine prepolymer (4.9 g) was added while stirring with a stirrer (manufactured by HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle size of about 170 nm were confirmed. It was.

[Example 19]
(Step A) A 9.3 wt% 2-ethylhexyl vinyl ether-maleic anhydride copolymer (molecular weight: about 38,000) aqueous solution (80.7 g) and ultrapure water (44.3 g) were placed in a stainless steel beaker and homogenizer. The mixture was stirred with (IKAT25). Thereto, liquid crystal composition b (30 g) was added little by little, and then stirred for 3 minutes to emulsify. (Step B) This emulsion (120.5 g) was charged into Starburst (Sugino Machine: HJP-25001) and allowed to pass 5 times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 70 ° C., and melamine prepolymer (4.9 g) was added while stirring with a stirrer (manufactured by HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 1.0 wt% aqueous ammonia solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle size of about 120 nm were confirmed. It was.

[Example 20]
(Step A) A 5 wt% styrene-maleic anhydride copolymer (molecular weight: about 25,000) aqueous solution (140 g) was placed in a stainless beaker and stirred with a homogenizer (IKAT25). The liquid crystal composition b (21 g) was added little by little, and the mixture was stirred for 3 minutes to emulsify. (Step B) This emulsion (140.3 g) was charged into Starburst (Sugino Machine: HJP-25001) and passed three times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 70 ° C., and melamine prepolymer (7.3 g) was added while stirring with a stirrer (manufactured by HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 1.0 wt% aqueous ammonia solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was observed and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle size of about 250 nm were confirmed. It was.

[Example 21]
(Step A) A 9.7 wt% styrene-maleic anhydride copolymer (molecular weight: about 5,500) aqueous solution (90.8 g) and ultrapure water (90.1 g) were placed in a stainless steel beaker and homogenizer (IKAT25). And stirred. The liquid crystal composition c (28 g) was added little by little, and the mixture was stirred for 3 minutes to emulsify. (Step B) This emulsion (88.9 g) was charged into Starburst (Sugino Machine Co., Ltd .: HJP-25001) and passed three times at an extrusion pressure of 150 MPa. (Step C) Thereafter, the mixture was heated to 70 ° C., and the melamine prepolymer (2.9 g) was added while stirring with a stirrer (HEIDON: high power general purpose stirrer BLh1200), stirred for 15 minutes, and then heated to 80 ° C. And stirred for 105 minutes. After returning the reaction mixture to room temperature, the pH was adjusted to 7 with a 1.0 wt% aqueous ammonia solution to obtain a nanocapsule slurry.
A sample prepared by diluting the nanocapsule slurry with ultrapure water to an appropriate concentration was prepared and observed with a dynamic scattering particle size analyzer (Nanotrack UPA) manufactured by Nikkiso. Nanocapsules with an average particle diameter of about 130 nm were confirmed. It was.

As described above, according to the present invention, nanocapsules having an average particle diameter of 70 to 320 nm could be obtained, but in the prior art, only capsules having a large particle diameter of 2.5 to 3.5 μm were obtained. .

  This liquid crystal capsule is optically isotropic and can be used for a liquid crystal display element driven by a liquid crystal layer that is optically isotropic. Furthermore, it can be used for an element in an IPS or FFS mode. The element has good optical properties.

Claims (15)

A liquid crystal capsule having an average particle diameter of 10 nm to 380 nm, wherein the liquid crystal composition is covered with a capsule wall made of a melamine resin or a urea-formalin resin.   The liquid crystal capsule according to claim 1, wherein the liquid crystal composition is covered with a capsule wall made of melamine resin. The liquid crystal composition is at least one compound selected from the group of compounds represented by the formula (1) as the liquid crystal compound 1, and at least selected from the group of compounds represented by the formula (2) as the liquid crystal compound 2. The liquid crystal capsule according to claim 1 or 2, wherein the proportion of the compound containing one compound and having cyano is less than 3% by weight based on the whole liquid crystal composition.

In Formula (1) and Formula (2), R ¹ , R ² and R ³ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons. Rings A ¹ , A ² , A ³ , A ⁴ and A ⁵ are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro; -1,4-phenylene, 2,6-difluoro-1,4-phenylene, pyridine-2,5-diyl, pyrimidine-2,5-diyl, 1,3-dioxane-2,5-diyl, or tetrahydropyran be a ^{2,5-diyl; Z 1, Z 2, Z} 3, Z 4 and ^{Z 5} are each independently a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy ethynylene, While others are tetrafluoroethylene, of ^{Z 1} and ^{Z 2,} at least one is an ^{ethynylene; X 1, X 2, X} 3, X 4, X 5 and ^{X 6} are each independently hydrogen or fluorine But X ¹ and X ² are not simultaneously fluorine and X ⁴ and X ⁵ are not simultaneously fluorine; Y ¹ is fluorine, chlorine, carbon in which at least one hydrogen is replaced by halogen An alkyl having 1 to 12 carbon atoms, an alkoxy having 1 to 12 carbon atoms in which at least one hydrogen is replaced by a halogen, or an alkenyl having 2 to 12 carbon atoms in which at least one hydrogen is replaced by a halogen; or a 2, m is 0, 1 or 2, if l and m is 2, ^the ring ^{a 2} there are a plurality of, ring ^a 4, ^{Z 2} and ^{Z 4,} respectively Even Flip, it may be different. The liquid crystal capsule according to claim 3, wherein the liquid crystal composition further contains at least one compound selected from the group of compounds represented by formula (3) as the liquid crystal compound 3.

In Formula (3), R ⁴ and R ⁵ are independently alkyl having 1 to 12 carbons, alkoxy having 1 to 12 carbons, or alkenyl having 2 to 12 carbons; ring A ⁶ or ring A ⁷ Are independently 1,4-cyclohexylene, 1,4-phenylene, 2-fluoro-1,4-phenylene, 2,5-difluoro-1,4-phenylene, or 2,6-difluoro-1, be a 4-phenylene; Z ⁶ is a single bond, ethylene, vinylene, methyleneoxy, carbonyloxy, difluoromethyleneoxy ethynylene or be a tetrafluoroethylene,; Z ⁷ is a single bond, ethylene, vinylene, methyleneoxy, Carbonyloxy, difluoromethyleneoxy or tetrafluoroethylene; n is 0, 1 or 2 and n represents 2 If, ring A ^7, and Z ⁷ there is a plurality, even in each same or different; provided that the compound represented by the formula (1) is excluded.   The liquid crystal composition has an optical anisotropy at a wavelength of 589 nm measured at 25 ° C. in the range of 0.20 to 0.35, and a dielectric anisotropy at a frequency of 1 kHz measured at 25 ° C. in the range of 8 to 40. The liquid crystal capsule according to any one of claims 1 to 4, wherein   The method for producing a liquid crystal capsule according to any one of claims 1 to 5.   Step A for preparing a microemulsion from a mixed material obtained by mixing a liquid crystal composition and a surfactant, Step B for preparing a nanoemulsion from the microemulsion, and a liquid crystal prepared by mixing a melamine prepolymer into the nanoemulsion. The manufacturing method of the liquid crystal capsule of Claim 6 including the process C which manufactures a capsule.   The method for producing a liquid crystal capsule according to claim 6 or 7, wherein the surfactant comprises a hydrolyzate of a copolymer of an electron donating monomer and maleic anhydride in radical polymerization.   The method for producing a liquid crystal capsule according to any one of claims 6 to 8, wherein the surfactant contains a hydrolyzate of 1-octadecene-maleic anhydride copolymer.   The method for producing a liquid crystal capsule according to claim 6 or 7, wherein the surfactant comprises a hydrolyzate of a styrene-maleic anhydride copolymer.   The method for producing a liquid crystal capsule according to any one of claims 6 to 8, wherein the surfactant used in the method for producing a liquid crystal capsule has a weight average molecular weight of 1,000 to 500,000.   The method for producing a liquid crystal capsule according to any one of claims 6 to 11, wherein a high-pressure atomizer is used in step B.   The method for producing a liquid crystal capsule according to any one of claims 6 to 12, wherein the content of the surfactant is 1 to 50 parts by weight with respect to 100 parts by weight of the liquid crystal composition.   14. The method for producing a liquid crystal capsule according to claim 6, wherein the content of the capsule wall is 1 to 60 parts by weight with respect to 100 parts by weight of the liquid crystal composition.   The method for producing a liquid crystal capsule according to any one of claims 6 to 14, wherein the content of the liquid crystal composition is 50 to 90% by weight based on the total amount of the liquid crystal capsule.