WO2021193585A1 - Rod-like particles containing fluoroapatite as main component, and colloidal solution containing same - Google Patents

Rod-like particles containing fluoroapatite as main component, and colloidal solution containing same Download PDF

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WO2021193585A1
WO2021193585A1 PCT/JP2021/011843 JP2021011843W WO2021193585A1 WO 2021193585 A1 WO2021193585 A1 WO 2021193585A1 JP 2021011843 W JP2021011843 W JP 2021011843W WO 2021193585 A1 WO2021193585 A1 WO 2021193585A1
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rod
fluoroapatite
shaped particles
main component
liquid crystal
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PCT/JP2021/011843
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French (fr)
Japanese (ja)
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隆史 加藤
智司 梶山
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国立大学法人 東京大学
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    • C—CHEMISTRY; METALLURGY
    • C01—INORGANIC CHEMISTRY
    • C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
    • C01B25/00—Phosphorus; Compounds thereof
    • C01B25/16—Oxyacids of phosphorus; Salts thereof
    • C01B25/26—Phosphates
    • C01B25/32—Phosphates of magnesium, calcium, strontium, or barium

Definitions

  • the present invention relates to a method for preparing rod-shaped particles containing fluoroapatite as a main component, a colloidal solution containing the rod-shaped particles, and rod-shaped particles containing fluoroapatite as a main component. More specifically, the present invention controls liquid crystal by controlling the size of rod-shaped particles containing fluoroapatite, which is known to have high chemical stability, mechanical stability and biocompatibility. It relates to a material that exhibits properties and exhibits a structural color by scattering light of a specific wavelength.
  • Structural color is a phenomenon in which light is anisotropically scattered, and materials showing structural color are attracting attention as optical materials. So far, many materials showing structural colors have been found in organic polymer cholesteric liquid crystals, spherical particles such as silica and melanin, and sheet-like substances such as inorganic layered hydroxides and layered oxides (non-patented). Document 1). On the other hand, for rod-shaped particles that can be arranged one-dimensionally by mechanical stimulation, a liquid crystal material that exhibits a structural color has not been developed.
  • nanowhiskers such as chitin and cellulose exhibit cholesteric liquid crystal properties, but from the viewpoint of durability, it is important to create a material that exhibits structural color in inorganic colloidal particles.
  • the present inventors have developed a rod-shaped particle material having a narrow size dispersibility and exhibiting liquidity by using an organic polymer for calcium carbonate, hydroxyapatent particles, and the like.
  • Patent Documents 1 and 2 Non-Patent Documents 2 and 3.
  • the average thickness of these rod-shaped colloidal particles is 200 nm or less, and the average length is 500 nm or less. Desired. That is, further size control of the liquid crystal rod-shaped particles is required to selectively scatter the visible light region and emit a structural color.
  • fluoroapatite rod-shaped particles in which the hydroxyl groups of hydroxyapatite are replaced with fluorine atoms are obtained by forming calcium phosphate in the presence of an organic polymer in a solution containing fluorine ions. It was found that the rod-shaped particles exhibited liquidity. Furthermore, by adjusting the concentration, temperature condition, and pH of fluorine ions and organic polymers, it is possible to control the size of a wide range of rod-shaped particles, thereby providing a liquid crystal inorganic colloid material that exhibits a structural color in the liquid state. The present invention was completed.
  • the present invention [1] Rod-shaped particles containing fluoroapatite as a main component. [2] The rod-shaped particles according to [1], which exhibit liquid crystallinity. [3] The rod-shaped particles according to [1] or [2], wherein the average length of the particles is 80 nm to 1500 nm, and the average thickness of the particles is 20 nm to 800 nm. [4] The rod-shaped particle according to any one of [1] to [3], which has a structure in which fluoroapatite and an organic polymer are composited. [5] A colloidal solution containing rod-shaped particles containing fluoroapatite as a main component according to any one of [1] to [4].
  • a method for preparing rod-shaped particles containing fluoroapatite as a main component which comprises a step of separating and recovering. Is to provide.
  • liquid crystal inorganic colloid material having a particle size that selectively scatters visible light, which was difficult in biocompatible inorganic colloid liquid crystal materials such as calcium carbonate and hydroxyapatite. ..
  • biocompatible inorganic colloid liquid crystal materials such as calcium carbonate and hydroxyapatite. ..
  • liquid crystal rod-shaped particles in which a fluorine atom is introduced into hydroxyapatite, it becomes possible to develop a liquid crystal inorganic colloid material that is mechanically and chemically more stable. This makes it possible to apply it to optical materials such as cosmetics and inks and to control orientation using the characteristics of liquid crystals to produce optical materials that anisotropically scatter visible light.
  • the scanning electron micrograph of the rod-shaped particles containing fluoroapatite as a main component and the average size of the rod-shaped particles obtained in Example 5 are shown.
  • a photograph (FIG. 2 (a)) of a liquid crystal showing a structural color and a polarizing microscope photograph (FIG. 2 (b)) of the rod-shaped particles containing fluoroapatite as a main component of Example 1 in an aqueous-dispersed state are shown.
  • the results of measuring the transmitted light intensity of the fluoroapatite rod-shaped particles obtained in Example 1 for colloidal solutions having various concentrations are shown.
  • the results of observing the nanostructures of the fluoroapatite rod-shaped particles obtained in Example 1 (FIG.
  • Fluorapatite-based rod-shaped particles One embodiment of the present invention is rod-shaped particles containing fluoroapatite as a main component (hereinafter, also referred to as “fluorapatite-based rod-shaped particles of the present invention”).
  • the "main component” means the component contained most in terms of mass.
  • the fact that fluoroapatite is the main component means that fluoroapatite is contained in an amount of 50% by weight or more based on the total weight of the rod-shaped particles, and the content thereof is preferably based on the total mass of the rod-shaped particles. It is 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more.
  • the rod-shaped particles containing fluoroapatite as a main component of the present invention As a non-limiting example of the rod-shaped particles containing fluoroapatite as a main component of the present invention, a scanning electron micrograph of the rod-shaped particles containing fluoroapatite as a main component obtained in Example 5 described later, and an average of the rod-shaped particles. The size is shown in FIG.
  • the size of the rod-shaped particles containing fluoroapatite as a main component of the present invention is usually 80 nm to 1500 nm, preferably 80 nm to 1200 nm.
  • the average thickness of the particles (assuming that the particles are columnar, the average value of the diameters of the circles, that is, the average particle diameter) is usually 20 nm to 700 nm, preferably 20 nm to 400 nm. .. When the average length and the average thickness of the particles are in the above ranges, the rod-shaped particles exhibit liquid crystallinity.
  • the structural color of the rod-shaped particles containing fluoroapatite as a main component is in the range of 600 nm to 1000 nm and the average thickness (average particle size) is in the range of 100 nm to 300 nm, the structural color can be exhibited in the liquid crystal state.
  • the structural color of the rod-shaped particles containing fluoroapatite as a main component is deep blue or the like.
  • the average length and the average thickness (average particle diameter) of the rod-shaped particles are observed with a scanning electron microscope, and the sizes of 100 particles are arbitrarily measured to obtain the average.
  • the length and thickness of the rod-shaped particles containing fluoroapatite as the main component can be adjusted by changing the preparation conditions such as fluorine ions, organic polymer concentration, temperature conditions, and pH at the time of preparing the particles. be.
  • the rod-shaped particles containing fluoroapatite as a main component have a structure in which fluoroapatite and an organic polymer are composited.
  • the coexistence of organic polymers in the particle preparation process suppresses rapid crystallization, and by preparing synthetic conditions for the composite structure, it is extremely difficult. It is possible to prepare liquid crystal rod-shaped colloidal particles in a wide range of sizes.
  • the composite structure of fluoroapatite and organic polymer includes a structure in which the organic polymer is incorporated into rod-shaped particles containing fluoroapatite as the main component, and a structure in which the organic polymer is incorporated into rod-shaped particles containing fluoroapatite as the main component. Examples include, but are not limited to, a structure adsorbed on the surface and a state in which these structures are mixed.
  • an acidic organic polymer is preferable, and examples thereof include polymers derived from amino acids such as polyacrylic acid, polyglutamic acid and polyaspartic acid, polysulfonic acid and polyphosphonic acid.
  • polyacrylic acid is preferable because it has sufficient interaction with inorganic ions.
  • the content of the organic polymer in the rod-shaped particles is not particularly limited, but is usually 3 to 10% by weight.
  • the rod-shaped particles containing fluoroapatite as a main component of the present invention may contain other components as long as the effects of the present invention are not impaired.
  • a colloidal solution containing rod-shaped particles containing fluoroapatite as a main component and a liquid crystal composed of the colloidal solution is a colloidal solution containing rod-shaped particles containing fluoroapatite as a main component of the present invention (hereinafter, "" Also referred to as “colloidal solution of the present invention”).
  • the colloidal solution is a colloidal aqueous solution.
  • the colloidal solution of the present invention can contain an organic solvent such as ethylene glycol, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, dioxane, methanol, ethanol and butanol within a range that does not impair the effects of the present invention.
  • an organic solvent such as ethylene glycol, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, dioxane, methanol, ethanol and butanol
  • colloidal solution of the present invention is a colloidal solution having a volume fraction of rod-shaped particles containing fluoroapatite as a main component of 12 to 33 vol%.
  • Another aspect of the colloidal solution of the present invention is a liquid crystal having a volume fraction of rod-shaped particles containing fluoroapatite as a main component of 12 to 33 vol%, preferably 18 to 33 vol%, and more preferably 20 to 30 vol%. It is a sex colloidal solution.
  • FIG. 2A is a photograph of a liquid crystal showing a structural color in which rod-shaped particles containing fluoroapatite as a main component, which will be described later, are in an aqueous dispersion state
  • FIG. 2B is a polarizing micrograph thereof. be.
  • Another aspect of the present invention is a liquid crystal composed of a colloidal solution containing rod-shaped particles containing the fluoroapatite of the present invention as a main component. Further, one aspect of the present invention is a liquid crystal composed of a colloidal solution having a volume fraction of rod-shaped particles containing fluoroapatite as a main component of the present invention of 18 to 33 vol%, preferably 20 to 30 vol%.
  • Another aspect of the polarizing present invention is a polarizing film rod-shaped particles fluoroapatite of the present invention as a main component is oriented.
  • the alignment film of the present invention can be obtained by applying shear to the rod-shaped particles containing the fluoroapatite of the present invention as a main component.
  • One embodiment of the present invention is an alignment film in which the c-axis of the fluoroapatite crystal is approximately oriented in the shear direction.
  • an alignment film is formed by sandwiching a colloidal solution containing rod-shaped particles containing fluoroapatite as a main component, which exhibits a liquid crystal phase, between substrates such as glass and applying shear in one direction. Can be obtained.
  • Method for preparing rod-shaped particles containing fluoroapatite as a main component Another aspect of the present invention is (1) a compound that produces calcium ions, a compound that produces phosphate ions, a compound that produces fluorine ions, and an organic polymer.
  • This is a method for preparing rod-shaped particles containing fluoroapatite as a main component, which comprises a step of preparing a reaction solution containing the above-mentioned reaction solution and (2) a step of separating and recovering a precipitate from the reaction solution.
  • an acidic organic polymer is preferable, and examples thereof include polymers derived from amino acids such as polyacrylic acid, polyglutamic acid and polyaspartic acid. Of these, polyacrylic acid is preferable. Further, the type of the organic polymer may be one type or two or more types may be used.
  • the concentration range of the organic polymer (preferably polyacrylic acid) in the reaction solution is 7.2 ⁇ 10 -3 % by weight or more, preferably 3.6 ⁇ 10-2 % by weight or more, and 1.5 ⁇ About 10 -1 % by weight or less is appropriate.
  • the average weight molecular weight of polyacrylic acid those of about 2000 to 5000 can be used.
  • Calcium chloride can be preferably used as the compound that produces calcium ions.
  • the concentration of calcium ions in the reaction solution is 0.005 mol / L or more, preferably 0.01 mol / L or more, 0.1 mol / L or less, preferably 0.05 mol / L or less.
  • the portion corresponding to X of CaX may be another compound as long as it has a solubility that can form a solution of about 100 mM.
  • acetic acid can be mentioned, and calcium acetate (Ca (CH 3 COO) 2 ) can also be preferably used.
  • disodium hydrogen phosphate Na 2 HPO 4
  • hydrates thereof e.g., Na 2 HPO 4 ⁇ 12H 2 O
  • dipotassium hydrogen phosphate K 2 HPO 4
  • tripotassium phosphate K 3 PO 4
  • trisodium phosphate Na 3 PO 4
  • triammonium phosphate ((NH 4 ) 3 PO 4 ) and These hydrates can also be used.
  • concentration of phosphate ions in the reaction solution is 0.02 mol / L or more, preferably 0.05 mol / L or more and 0.1 mol / L or less.
  • Sodium fluoride (NaF) can be preferably used as the compound that produces fluorine ions.
  • Lithium fluoride (LiF) and potassium fluoride (KF) can also be used.
  • the concentration of fluorine ions in the reaction solution is 0.005 mol / L or more, preferably 0.01 mol / L or more and 0.05 mol / L or less.
  • the pH of the reaction solution is usually 5 to 12, preferably 5 to 8.
  • the reaction solution is usually prepared at room temperature and atmospheric pressure, and stirring is carried out at about 5 ° C. to 80 ° C., preferably 20 ° C. to 60 ° C. for several hours to 150 hours under atmospheric pressure. It is done in.
  • rod-shaped particles containing fluoroapatite as a main component By stirring the reaction solution as described above, rod-shaped particles containing fluoroapatite as a main component can be formed.
  • the precipitate formed after stirring can be separated to obtain rod-shaped particles containing fluoroapatite as a main component. Further, the precipitate can be recovered by centrifuging, washing with an appropriate amount of ultrapure water, and vacuum drying, but the present invention is not limited to this.
  • Example 1 CaCl 2 0.02mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at room temperature for 24 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and then vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 784 ⁇ 94 nm
  • the average thickness (width) was 193 ⁇ 27 nm
  • the aspect ratio of the particles was 4.10 ⁇ 0.49. rice field.
  • the main component of the particles obtained from X-ray diffraction measurement and transmission electron microscope observation was fluoroapatite, and from the results of thermogravimetric analysis, in addition to 90 wt% fluoroapatite, 5 wt% polyacrylic acid. It was found to contain 5 wt% water.
  • the liquid crystal phase was confirmed in a water-dispersed state. A polarized image and fluidity peculiar to the liquid crystal display were observed from the dispersed aqueous solution of 45 wt% of rod-shaped particles. Structural color was observed in the liquid crystal state.
  • Example 2 CaCl 2 0.02mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at room temperature for 24 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and then vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 830 ⁇ 111 nm
  • the average thickness was 223 ⁇ 33 nm
  • the aspect ratio of the particles was 3.76 ⁇ 0.53.
  • Example 3 CaCl 2 0.01mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 3.6 ⁇ 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at room temperature for 45 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 933 ⁇ 155 nm
  • the average thickness was 197 ⁇ 25 nm
  • the aspect ratio of the particles was 4.79 ⁇ 0.8.
  • Example 4 CaCl 2 0.01mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 3.6 ⁇ 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at room temperature for 30 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder. When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 699 ⁇ 92 nm, the average thickness was 122 ⁇ 15 nm, and the aspect ratio of the particles was 5.78 ⁇ 0.66. Structural color was observed in the liquid crystal state.
  • Example 5 CaCl 2 0.01mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05 mol / L, NaF 0.01mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt 100 ml of the reaction solution containing% was stirred at 60 ° C. for 96 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 837 ⁇ 83 nm
  • the average thickness was 212 ⁇ 17 nm
  • the aspect ratio of the particles was 3.97 ⁇ 0.45. From the results of X-ray diffraction measurement and transmission electron microscope observation, it was confirmed that it was fluoroapatite, and the structural color was observed in the liquid state.
  • Example 6 CaCl 2 0.02 mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt 100 ml of the reaction solution containing% was stirred at 40 ° C. for 12 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 1104 ⁇ 150 nm
  • the average thickness was 357 ⁇ 65 nm
  • the aspect ratio of the particles was 3.14 ⁇ 0.43.
  • Example 7 CaCl 2 0.01mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05 mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 3.6 ⁇ 10 -2 wt 100 ml of the reaction solution containing% was stirred at 40 ° C. for 12 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 707 ⁇ 95 nm
  • the average thickness was 166 ⁇ 19 nm
  • the aspect ratio of the particles was 4.26 ⁇ 0.49.
  • Example 8 CaCl 2 0.02 mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt
  • a 400 ml reaction solution containing% was stirred at 10 ° C. for 60 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 733 ⁇ 70 nm
  • the average thickness was 153 ⁇ 24 nm
  • the aspect ratio of the particles was 4.83 ⁇ 0.52.
  • the structural color was shown in the liquid crystal state.
  • Example 9 CaCl 2 0.016mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.04mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 5.7 ⁇ 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at 10 ° C. for 240 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 936 ⁇ 161 nm
  • the average thickness was 163 ⁇ 37 nm
  • the aspect ratio of the particles was 5.87 ⁇ 0.73.
  • the structural color was shown in the liquid crystal state.
  • Example 10 CaCl 2 0.01mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05 mol / L, NaF 0.05mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt 100 ml of the reaction solution containing% was stirred at 60 ° C. for 3 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 1002 ⁇ 75 nm
  • the average thickness was 296 ⁇ 27 nm
  • the aspect ratio of the particles was 3.40 ⁇ 0.35.
  • the liquid crystal phase was shown in the water-dispersed state.
  • Example 11 CaCl 2 0.01mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.02mol / L, NaF 0.025mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at 60 ° C. for 18 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 1443 ⁇ 142 nm
  • the average thickness was 608 ⁇ 95 nm
  • the aspect ratio of the particles was 2.41 ⁇ 0.29.
  • the liquid crystal phase was shown in the water-dispersed state.
  • Example 12 CaCl 2 0.01mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 3.6 ⁇ 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at 40 ° C. for 65 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 379 ⁇ 63 nm
  • the average thickness was 94 ⁇ 14 nm
  • the aspect ratio of the particles was 4.02 ⁇ 0.34.
  • the liquid crystal phase was shown in the water-dispersed state.
  • Example 13 CaCl 2 0.008mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.04mol / L, NaF 0.032mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 2.9 ⁇ 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at room temperature for 60 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 285 ⁇ 37 nm
  • the average thickness was 66 ⁇ 8 nm
  • the aspect ratio of the particles was 4.35 ⁇ 0.53.
  • the liquid crystal phase was shown in the water-dispersed state.
  • Example 14 CaCl 2 0.02mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.03mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at room temperature for 12 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 262 ⁇ 33 nm
  • the average thickness was 68 ⁇ 8 nm
  • the aspect ratio of the particles was 3.91 ⁇ 0.48.
  • the liquid crystal phase was shown in the water-dispersed state.
  • Example 15 CaCl 2 0.02mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.025mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at 60 ° C. for 160 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 231 ⁇ 34 nm
  • the average thickness was 83 ⁇ 14 nm
  • the aspect ratio of the particles was 2.81 ⁇ 0.40.
  • the liquid crystal phase was shown in the water-dispersed state.
  • Example 16 CaCl 2 0.02mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.025mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 1.1 ⁇ 10 -1 wt % 100 ml of the reaction solution containing the above solution was stirred at 60 ° C. for 160 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was 154 ⁇ 25 nm
  • the average thickness was 56 ⁇ 9 nm
  • the aspect ratio of the particles was 2.79 ⁇ 0.50. It was confirmed by X-ray diffraction measurement that it was fluoroapatite, and from the results of thermogravimetric analysis, it was found that 8 wt% polyacrylic acid and 4 wt% water were contained in addition to 88 wt% fluoroapatite. ..
  • the liquid crystal phase was shown in the water-dispersed state.
  • Example 17 CaCl 2 0.01mol / L, Na 2 HPO 4 ⁇ 12H 2 O 0.05mol / L, NaF 0.025mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 ⁇ 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at 60 ° C. for 72 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was about 130 nm
  • the average thickness was about 40 nm
  • the aspect ratio of the particles was about 3.2.
  • Example 18 400 ml containing CaCl 2 0.1 mol / L, K 3 PO 4 0.1 mol / L, KF 0.02 mol / L, polyacrylic acid (average weight molecular weight: 2,000) 7.2 ⁇ 10 -1 wt%
  • the reaction solution was stirred at 60 ° C. for 72 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was about 80 nm
  • the average thickness was about 25 nm
  • the aspect ratio of the particles was about 3.2.
  • the liquid crystal phase was shown in the water-dispersed state.
  • Example 19 400 ml containing CaCl 2 0.1 mol / L, K 3 PO 4 0.1 mol / L, KF 0.1 mol / L, polyacrylic acid (average weight molecular weight: 2,000) 7.2 ⁇ 10 -1 wt%
  • the reaction solution was stirred at 60 ° C. for 72 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
  • the average length was about 75 nm
  • the average thickness was about 30 nm
  • the aspect ratio of the particles was about 2.5.
  • the liquid crystal phase was shown in the water-dispersed state.
  • FIG. 3 shows the results of measuring the transmitted light intensity of the fluoroapatite rod-shaped particles obtained in Example 1 for colloidal solutions having various concentrations.
  • the liquid crystal state is shown from 22 vol% to 32 vol%.
  • Example 21 The results of observing the nanostructures of the fluoroapatite rod-shaped particles obtained in Example 1 are shown in FIG. 4 (a), and the results of crystal orientation analysis are shown in FIG. 4 (b). From the results of selected area electron diffraction (circle part of the transmission electron microscope image in FIG. 4B), it was suggested that the crystal c-axis of fluoroapatite and the long axis of the rod-shaped particles coincide with each other.
  • Example 22 The transmission electron microscope image and the result of elemental analysis mapping for the fluoroapatite rod-shaped particles obtained in Example 1 are shown in FIG. Fluorine is uniformly dispersed in the rod-shaped particles, suggesting that they are fluoroapatite particles.
  • FIG. 6 shows the measurement results of X-ray diffraction of the fluoroapatite rod-shaped particles obtained in Example 1.
  • the thermogravimetric analysis results of the fluoroapatite rod-shaped particles obtained in Example 1 are shown in FIG.
  • FIG. 8 shows the results of measuring the transmitted light intensity of the fluoroapatite powders of different sizes obtained in Examples 1, 4 and 8 in a water-dispersed state of 55 wt% and a thickness of about 0.05 mm.
  • A is the result for Example 4
  • B is the result for Example 8
  • C is the result for Example 1). It was found that light having wavelengths of 576 nm, 491 nm, and 542 nm or less was hardly transmitted, respectively. In this way, the scattering wavelength can be controlled by controlling the size of the particles containing fluoroapatite as a main component.
  • Example 25 With respect to the powder obtained in Example 1, a 60 wt% water-dispersed state showing a liquid crystal phase was produced, and shear was applied by sandwiching the powder on a glass substrate to produce a film oriented in one axis. .. From the X-ray diffraction measurement, it was found that the shear direction and the c-axis of the fluoroapatite crystal coincide with each other.
  • the rod-shaped particles containing fluoroapatite as a main component of the present invention can emit a structural color and can control the scattering wavelength
  • the constituent fluoroapatite is biocompatible and mechanical in addition to the optical material such as special ink. Since it exhibits strength and chemical stability, it is expected to be applied to daily necessities such as cosmetics.

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Abstract

[Problem] To provide liquid crystalline rod-like inorganic particles that can be produced through a low-cost simple synthesis process and that exhibits biocompatibility. [Solution] Rod-like particles containing fluoroapatite as a main component.

Description

フルオロアパタイトを主成分とする棒状粒子及びこれを含むコロイド溶液Fluorapatite-based rod-shaped particles and colloidal solution containing them
本発明は、フルオロアパタイトを主成分とする棒状粒子、当該棒状粒子を含むコロイド溶液、及びフルオロアパタイトを主成分とする棒状粒子の調製方法に関わる。より具体的には、本発明は、高い化学的安定性、機械的安定性及び生体適合性を有することが知られているフルオロアパタイトを主成分とする棒状粒子のサイズを制御することにより、液晶性を発現し、かつ、特定の波長の光を散乱することで構造色を示す材料に関するものである。 The present invention relates to a method for preparing rod-shaped particles containing fluoroapatite as a main component, a colloidal solution containing the rod-shaped particles, and rod-shaped particles containing fluoroapatite as a main component. More specifically, the present invention controls liquid crystal by controlling the size of rod-shaped particles containing fluoroapatite, which is known to have high chemical stability, mechanical stability and biocompatibility. It relates to a material that exhibits properties and exhibits a structural color by scattering light of a specific wavelength.
　構造色は光を異方的に散乱する現象であり、構造色を示す材料は光学材料として着目されている。これまで、構造色を示す材料としては、有機高分子のコレステリック液晶、シリカやメラニンなどの球状粒子、無機層状水酸化物及び層状酸化物などのシート状物質で多く見出されている（非特許文献１）。一方、 機械的刺激により一次元に配列できる棒状粒子については、 構造色を示す液晶性材料は開発されていない。 Structural color is a phenomenon in which light is anisotropically scattered, and materials showing structural color are attracting attention as optical materials. So far, many materials showing structural colors have been found in organic polymer cholesteric liquid crystals, spherical particles such as silica and melanin, and sheet-like substances such as inorganic layered hydroxides and layered oxides (non-patented). Document 1). On the other hand, for rod-shaped particles that can be arranged one-dimensionally by mechanical stimulation, a liquid crystal material that exhibits a structural color has not been developed.
　液晶性棒状コロイド粒子に関しては、キチンやセルロースなどのナノウィスカーがコレステリック液晶性を示すが、 耐久性という観点からは、無機コロイド粒子において構造色を示す材料を作成することが重要である。 Regarding liquid crystal rod-shaped colloidal particles, nanowhiskers such as chitin and cellulose exhibit cholesteric liquid crystal properties, but from the viewpoint of durability, it is important to create a material that exhibits structural color in inorganic colloidal particles.
　液晶性の無機棒状粒子に関して、本発明者らは、炭酸カルシウムやヒドロキシアパタイト粒子などを対象として、有機高分子を用いて、サイズ分散性が狭く液晶性を発現する棒状粒子材料を開発している（特許文献１及び２、非特許文献２及び３）。
　しかしながら、これらの棒状コロイド粒子の平均太さは２００ｎｍ以下で、平均長さは５００ｎｍ以下であり、可視光を選択的に散乱して構造色を発するには、より大きな液晶性棒状粒子の開発が求められる。つまり、可視光領域を選択的に散乱し、構造色を発するには液晶性棒状粒子の更なるサイズ制御が必要となる。 Regarding the liquid crystal inorganic rod-shaped particles, the present inventors have developed a rod-shaped particle material having a narrow size dispersibility and exhibiting liquidity by using an organic polymer for calcium carbonate, hydroxyapatent particles, and the like. (Patent Documents 1 and 2, Non-Patent Documents 2 and 3).
However, the average thickness of these rod-shaped colloidal particles is 200 nm or less, and the average length is 500 nm or less. Desired. That is, further size control of the liquid crystal rod-shaped particles is required to selectively scatter the visible light region and emit a structural color.
　また、ヒドロキシアパタイトにフッ素を導入したフルオロアパタイトを主成分とすることで、生体適合性を維持しながら、より高い耐久性、すなわち機械的強度及び化学的安定性を実現できると考えられ、フルオロアパタイトを主成分とする液晶性を示す棒状コロイド粒子の開発も望まれているが、未だ達成されていない。 In addition, it is considered that higher durability, that is, mechanical strength and chemical stability can be realized while maintaining biocompatibility by using fluoroapatite, which is obtained by introducing fluorine into hydroxyapatite, as the main component. The development of rod-shaped colloidal particles exhibiting liquidity containing the above as a main component has also been desired, but has not yet been achieved.
特開２０１６－１７５７９２号公報Japanese Unexamined Patent Publication No. 2016-175792 特開２０１７－１６５６０６号公報JP-A-2017-165606
　本発明は、低コストでかつ簡便な合成プロセスで作製が可能であり、生体適合性を示す液晶性棒状無機粒子を提供することを目的とする。
　また、本発明は、かかる液晶性棒状無機粒子において、粒子の制御を行い、可視光を選択的に散乱し液晶状態で構造色を示す液晶性無機コロイド材料を開発することを目的とする。 An object of the present invention is to provide liquid crystal rod-shaped inorganic particles which can be produced by a low-cost and simple synthetic process and exhibit biocompatibility.
Another object of the present invention is to develop a liquid crystal inorganic colloidal material that controls particles in such liquid crystal rod-shaped inorganic particles, selectively scatters visible light, and exhibits a structural color in a liquid crystal state.
　本発明者らが鋭意検討をしたところ、フッ素イオンを含む溶液内で、有機高分子の存在下、リン酸カルシウムを形成させることにより、ヒドロキシアパタイトの水酸基がフッ素原子に置換したフルオロアパタイトの棒状粒子を得ることができ、この棒状粒子が液晶性を示すことが見出された。
　更に、フッ素イオン、有機高分子の濃度、温度条件、ｐＨを調整することによって.幅広い棒状粒子のサイズ制御を行うことができ、これにより液晶状態で構造色を示す液晶性無機コロイド材料を提供できることを見出し、本発明を完成した。　  As a result of diligent studies by the present inventors, fluoroapatite rod-shaped particles in which the hydroxyl groups of hydroxyapatite are replaced with fluorine atoms are obtained by forming calcium phosphate in the presence of an organic polymer in a solution containing fluorine ions. It was found that the rod-shaped particles exhibited liquidity.
Furthermore, by adjusting the concentration, temperature condition, and pH of fluorine ions and organic polymers, it is possible to control the size of a wide range of rod-shaped particles, thereby providing a liquid crystal inorganic colloid material that exhibits a structural color in the liquid state. The present invention was completed.
　即ち、本発明は、
［１］フルオロアパタイトを主成分とする棒状粒子。
［２］液晶性を示す、［１］に記載の棒状粒子。
［３］粒子の平均長さが８０ｎｍ～１５００ｎｍであり、粒子の平均太さが２０ｎｍ～８００ｎｍである、［１］又は［２］に記載の棒状粒子。
［４］フルオロアパタイトと有機高分子とが複合化した構造を有する、［１］～［３］のいずれか１項に記載の棒状粒子。
［５］［１］～［４］のいずれか１項に記載のフルオロアパタイトを主成分とする棒状粒子を含むコロイド溶液。
［６］フルオロアパタイトを主成分とする棒状粒子の体積分率が１２～３３ｖｏｌ％である、［５］に記載のコロイド溶液。
［７］液晶性を示す［６］に記載のコロイド溶液。
［８］［１］～［４］のいずれか１項に記載のフルオロアパタイトを主成分とする棒状粒子を含むコロイド溶液からなる液晶。
［９］前記コロイド溶液中におけるフルオロアパタイトを主成分とする棒状粒子の体積分率が１８～３３ｖｏｌ％である、［８］に記載の液晶。
［１０］［１］～［４］のいずれか１項に記載のフルオロアパタイトを主成分とする棒状粒子が配向した偏光膜。
［１１］前記棒状粒子のｃ軸がせん断方向におおよそ配向している、［１０］に記載の配向膜。
［１２］（１）カルシウムイオンを生成する化合物、リン酸イオンを生成する化合物、フッ素イオンを生成する化合物、及び有機高分子を含む反応溶液を調製する工程、（２）前記反応溶液から析出物を分離して回収する工程を含む、フルオロアパタイトを主成分とする棒状粒子を調製する方法。
を提供するものである。 That is, the present invention
[1] Rod-shaped particles containing fluoroapatite as a main component.
[2] The rod-shaped particles according to [1], which exhibit liquid crystallinity.
[3] The rod-shaped particles according to [1] or [2], wherein the average length of the particles is 80 nm to 1500 nm, and the average thickness of the particles is 20 nm to 800 nm.
[4] The rod-shaped particle according to any one of [1] to [3], which has a structure in which fluoroapatite and an organic polymer are composited.
[5] A colloidal solution containing rod-shaped particles containing fluoroapatite as a main component according to any one of [1] to [4].
[6] The colloidal solution according to [5], wherein the volume fraction of the rod-shaped particles containing fluoroapatite as a main component is 12 to 33 vol%.
[7] The colloidal solution according to [6], which exhibits liquid crystallinity.
[8] A liquid crystal display comprising a colloidal solution containing rod-shaped particles containing fluoroapatite as a main component according to any one of [1] to [4].
[9] The liquid crystal display according to [8], wherein the volume fraction of the rod-shaped particles containing fluoroapatite as a main component in the colloidal solution is 18 to 33 vol%.
[10] A polarizing film in which rod-shaped particles containing fluoroapatite as a main component are oriented according to any one of [1] to [4].
[11] The alignment film according to [10], wherein the c-axis of the rod-shaped particles is substantially oriented in the shear direction.
[12] (1) A step of preparing a reaction solution containing a compound that produces calcium ions, a compound that produces phosphate ions, a compound that produces fluorine ions, and an organic polymer, (2) a precipitate from the reaction solution. A method for preparing rod-shaped particles containing fluoroapatite as a main component, which comprises a step of separating and recovering.
Is to provide.
　本発明により、炭酸カルシウムやヒドロキシアパタイトなどの生体適合性の無機コロイド液晶材料において困難であった、可視光を選択的に散乱する粒子サイズを有する液晶性無機コロイド材料を提供することが可能である。さらに、ヒドロキシアパタイトにフッ素原子を導入した液晶性棒状粒子を開発することにより、機械的及び化学的により安定な液晶性無機コロイド材料の開発が可能となる。これにより、化粧品やインクなどの光学材料への応用および液晶の特性を利用した配向制御を行い、可視光を異方的に散乱する光学材料の作製が可能となる。 INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide a liquid crystal inorganic colloid material having a particle size that selectively scatters visible light, which was difficult in biocompatible inorganic colloid liquid crystal materials such as calcium carbonate and hydroxyapatite. .. Furthermore, by developing liquid crystal rod-shaped particles in which a fluorine atom is introduced into hydroxyapatite, it becomes possible to develop a liquid crystal inorganic colloid material that is mechanically and chemically more stable. This makes it possible to apply it to optical materials such as cosmetics and inks and to control orientation using the characteristics of liquid crystals to produce optical materials that anisotropically scatter visible light.
実施例５で得られたフルオロアパタイトを主成分とする棒状粒子の走査型電子顕微鏡写真及び当該棒状粒子の平均サイズを示す。The scanning electron micrograph of the rod-shaped particles containing fluoroapatite as a main component and the average size of the rod-shaped particles obtained in Example 5 are shown. 実施例１のフルオロアパタイトを主成分とする棒状粒子を水分散状態とした、構造色を示す液晶の写真（図２（ａ））及びその偏光顕微鏡写真（図２（ｂ））を示す。A photograph (FIG. 2 (a)) of a liquid crystal showing a structural color and a polarizing microscope photograph (FIG. 2 (b)) of the rod-shaped particles containing fluoroapatite as a main component of Example 1 in an aqueous-dispersed state are shown. 実施例１で得られたフルオロアパタイト棒状粒子について種々の濃度のコロイド溶液について透過光強度の測定を行った結果を示す。The results of measuring the transmitted light intensity of the fluoroapatite rod-shaped particles obtained in Example 1 for colloidal solutions having various concentrations are shown. 実施例１で得られたフルオロアパタイト棒状粒子についてナノ構造を観察した結果（図４（ａ））、及び結晶方位解析を行った結果（図４（ｂ））を示す。The results of observing the nanostructures of the fluoroapatite rod-shaped particles obtained in Example 1 (FIG. 4 (a)) and the results of crystal orientation analysis (FIG. 4 (b)) are shown. 実施例１で得られたフルオロアパタイト棒状粒子について透過型電子顕微鏡像と元素分析マッピングの結果を示す。The transmission electron microscope image and the result of elemental analysis mapping are shown for the fluoroapatite rod-shaped particles obtained in Example 1. 実施例１で得られたフルオロアパタイト棒状粒子についてＸ線回折の測定結果を示す。The measurement result of X-ray diffraction is shown for the fluoroapatite rod-shaped particles obtained in Example 1. 実施例１で得られたフルオロアパタイト棒状粒子について熱重量分析結果を示す。The results of thermogravimetric analysis of the fluoroapatite rod-shaped particles obtained in Example 1 are shown. 実施例１、実施例４、実施例８で得られたサイズの異なるフルオロアパタイト粉体について５５ｗｔ％の水分散状態、０．０５ｍｍ程度の厚みで透過光強度測定を行った結果を示す。The results of the transmitted light intensity measurement of the fluoroapatite powders of different sizes obtained in Examples 1, 4 and 8 in a water-dispersed state of 55 wt% and a thickness of about 0.05 mm are shown. 実施例１で得られた粉体について液晶状態でせん断をかけることにより配向させた偏光顕微鏡写真（図９（ａ））、及び極座標プロット（００２反射、２θ＝２５．６°）による配向評価の結果（図９（ｂ））を示す。Orientation evaluation by polarization micrograph (FIG. 9 (a)) oriented by shearing the powder obtained in Example 1 in a liquid crystal state and polar coordinate plot (002 reflection, 2θ = 25.6 °). The result (FIG. 9 (b)) is shown.
　以下、本発明の実施の形態について図面を参照しながら詳細に説明する。 Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
１．フルオロアパタイトを主成分とする棒状粒子
　本発明の１つの態様は、フルオロアパタイトを主成分とする棒状粒子である（以下「本発明のフルオロアパタイトを主成分とする棒状粒子」ともいう）。 1. 1. Fluorapatite-based rod-shaped particles One embodiment of the present invention is rod-shaped particles containing fluoroapatite as a main component (hereinafter, also referred to as “fluorapatite-based rod-shaped particles of the present invention”).
　本明細書において、「主成分」は質量基準で最も多く含まれる成分を意味する。
　本明細書において、フルオロアパタイトを主成分とするとは、棒状粒子の全重量に基づき、フルオロアパタイトを５０重量％以上含むことを意味し、その含有量は、棒状粒子の全質量に基づき、好ましくは７０重量％以上、より好ましくは８０重量％以上、さらに好ましくは９０重量％以上である。 In the present specification, the "main component" means the component contained most in terms of mass.
In the present specification, the fact that fluoroapatite is the main component means that fluoroapatite is contained in an amount of 50% by weight or more based on the total weight of the rod-shaped particles, and the content thereof is preferably based on the total mass of the rod-shaped particles. It is 70% by weight or more, more preferably 80% by weight or more, still more preferably 90% by weight or more.
　本発明のフルオロアパタイトを主成分とする棒状粒子の非限定的例として、後述する実施例５で得られたフルオロアパタイトを主成分とする棒状粒子の走査型電子顕微鏡写真、及び当該棒状粒子の平均サイズを図１に示す。 As a non-limiting example of the rod-shaped particles containing fluoroapatite as a main component of the present invention, a scanning electron micrograph of the rod-shaped particles containing fluoroapatite as a main component obtained in Example 5 described later, and an average of the rod-shaped particles. The size is shown in FIG.
　本発明のフルオロアパタイトを主成分とする棒状粒子の大きさとしては、平均流さは、通常８０ｎｍ～１５００ｎｍであり、好ましくは８０ｎｍ～１２００ｎｍである。また、粒子の平均太さ（粒子が円柱状と仮定した場合は、円の直径の平均値、即ち、平均粒子径に該当する）は、通常２０ｎｍ～７００ｎｍであり、好ましくは２０ｎｍ～４００ｎｍである。粒子の平均長さと平均太さが上記の範囲にあると、棒状粒子が液晶性を示す。 The size of the rod-shaped particles containing fluoroapatite as a main component of the present invention is usually 80 nm to 1500 nm, preferably 80 nm to 1200 nm. The average thickness of the particles (assuming that the particles are columnar, the average value of the diameters of the circles, that is, the average particle diameter) is usually 20 nm to 700 nm, preferably 20 nm to 400 nm. .. When the average length and the average thickness of the particles are in the above ranges, the rod-shaped particles exhibit liquid crystallinity.
　更に、フルオロアパタイトを主成分とする棒状粒子の平均長さが６００ｎｍ～１０００ｎｍ、平均太さ（平均粒子径）が１００ｎｍ～３００ｎｍの範囲にあると、液晶状態で構造色を示すことができる。　　
　フルオロアパタイトを主成分とする棒状粒子が示す構造色としては、ディープブルー等である。 Further, when the average length of the rod-shaped particles containing fluoroapatite as a main component is in the range of 600 nm to 1000 nm and the average thickness (average particle size) is in the range of 100 nm to 300 nm, the structural color can be exhibited in the liquid crystal state.
The structural color of the rod-shaped particles containing fluoroapatite as a main component is deep blue or the like.
　本明細書において、棒状粒子の平均長さ及び平均太さ（平均粒子径）は、走査型電子顕微鏡で観察して、任意に１００個の粒子のサイズを計測し、平均を求める。
　フルオロアパタイトを主成分とする棒状粒子の長さ及び太さは、粒子を調製時のフッ素イオン、有機高分子の濃度、温度条件、ｐＨ等の調製条件を変更することにより調整することが可能である。 In the present specification, the average length and the average thickness (average particle diameter) of the rod-shaped particles are observed with a scanning electron microscope, and the sizes of 100 particles are arbitrarily measured to obtain the average.
The length and thickness of the rod-shaped particles containing fluoroapatite as the main component can be adjusted by changing the preparation conditions such as fluorine ions, organic polymer concentration, temperature conditions, and pH at the time of preparing the particles. be.
　本発明の１つの側面において、フルオロアパタイトを主成分とする棒状粒子は、フルオロアパタイトと有機高分子とが複合化した構造を有する。理論に拘束されることを意図するものではないが、粒子の調製過程で有機高分子が共存することで、急激な結晶化が抑制されると共に、複合構造に合成条件を調製することにより、非常に広いサイズ範囲の液晶性棒状コロイド粒子の調製が可能となる。 In one aspect of the present invention, the rod-shaped particles containing fluoroapatite as a main component have a structure in which fluoroapatite and an organic polymer are composited. Although it is not intended to be bound by theory, the coexistence of organic polymers in the particle preparation process suppresses rapid crystallization, and by preparing synthetic conditions for the composite structure, it is extremely difficult. It is possible to prepare liquid crystal rod-shaped colloidal particles in a wide range of sizes.
　フルオロアパタイトと有機高分子とが複合化した構造としては、有機高分子がフルオロアパタイトを主成分とする棒状粒子内に取り込まれている構造、有機高分子がフルオロアパタイトを主成分とする棒状粒子の表面に吸着している構造、これらの構造が混合している状態等が挙げられるが、これらに限定されるものではない。 The composite structure of fluoroapatite and organic polymer includes a structure in which the organic polymer is incorporated into rod-shaped particles containing fluoroapatite as the main component, and a structure in which the organic polymer is incorporated into rod-shaped particles containing fluoroapatite as the main component. Examples include, but are not limited to, a structure adsorbed on the surface and a state in which these structures are mixed.
　有機高分子としては、酸性有機高分子が好ましく、例えば、ポリアクリル酸、ポリグルタミン酸及びポリアスパラギン酸等のアミノ酸由来のポリマー、ポリスルホン酸、ポリホスホン酸等が挙げられる。これらの中でも、ポリアクリル酸が無機イオンとの相互作用が十分である点で好ましい。 As the organic polymer, an acidic organic polymer is preferable, and examples thereof include polymers derived from amino acids such as polyacrylic acid, polyglutamic acid and polyaspartic acid, polysulfonic acid and polyphosphonic acid. Among these, polyacrylic acid is preferable because it has sufficient interaction with inorganic ions.
　棒状粒子中の有機高分子の含有量については特に制限がないが、通常３～１０重量％である。 The content of the organic polymer in the rod-shaped particles is not particularly limited, but is usually 3 to 10% by weight.
　本発明のフルオロアパタイトを主成分とする棒状粒子には、本発明の効果を損なわない範囲においてその他の成分が含まれていてもよい。 The rod-shaped particles containing fluoroapatite as a main component of the present invention may contain other components as long as the effects of the present invention are not impaired.
２．フルオロアパタイトを主成分とする棒状粒子を含むコロイド溶液及び当該コロイド溶液からなる液晶
　本発明のもう１つの態様は、本発明のフルオロアパタイトを主成分とする棒状粒子を含むコロイド溶液である（以下「本発明のコロイド溶液」ともいう）。
　好ましくは、上記コロイド溶液はコロイド水溶液である。 2. A colloidal solution containing rod-shaped particles containing fluoroapatite as a main component and a liquid crystal composed of the colloidal solution Another aspect of the present invention is a colloidal solution containing rod-shaped particles containing fluoroapatite as a main component of the present invention (hereinafter, "" Also referred to as "colloidal solution of the present invention").
Preferably, the colloidal solution is a colloidal aqueous solution.
　また、本発明のコロイド溶液は、エチレングリコール、ジメチルスルホキシド、ジメチルホルムアミド、テトラヒドロフラン、ジオキサン、メタノール、エタノール、ブタノール等の有機溶媒を本発明の効果を損なわない範囲で含有することができる。 Further, the colloidal solution of the present invention can contain an organic solvent such as ethylene glycol, dimethyl sulfoxide, dimethylformamide, tetrahydrofuran, dioxane, methanol, ethanol and butanol within a range that does not impair the effects of the present invention.
　本発明のコロイド溶液の１つの好ましい側面は、フルオロアパタイトを主成分とする棒状粒子の体積分率が１２～３３ｖｏｌ％であるコロイド溶液である。
　また、本発明のコロイド溶液のもう１つの側面は、フルオロアパタイトを主成分とする棒状粒子の体積分率が１２～３３ｖｏｌ％、好ましくは１８～３３ｖｏｌ％、より好ましくは２０～３０ｖｏｌ％である液晶性コロイド溶液である。 One preferable aspect of the colloidal solution of the present invention is a colloidal solution having a volume fraction of rod-shaped particles containing fluoroapatite as a main component of 12 to 33 vol%.
Another aspect of the colloidal solution of the present invention is a liquid crystal having a volume fraction of rod-shaped particles containing fluoroapatite as a main component of 12 to 33 vol%, preferably 18 to 33 vol%, and more preferably 20 to 30 vol%. It is a sex colloidal solution.
　本発明のコロイド溶液の非限定的例を図２に示す。図２（ａ）は、後述する実施例１のフルオロアパタイトを主成分とする棒状粒子を水分散状態とした、構造色を示す液晶の写真であり、図２（ｂ）はその偏光顕微鏡写真である。 A non-limiting example of the colloidal solution of the present invention is shown in FIG. FIG. 2A is a photograph of a liquid crystal showing a structural color in which rod-shaped particles containing fluoroapatite as a main component, which will be described later, are in an aqueous dispersion state, and FIG. 2B is a polarizing micrograph thereof. be.
　本発明のもう１つの態様は、本発明のフルオロアパタイトを主成分とする棒状粒子を含むコロイド溶液からなる液晶である。
　また、本発明の１つの側面は、本発明のフルオロアパタイトを主成分とする棒状粒子の体積分率が１８～３３ｖｏｌ％、好ましくは２０～３０ｖｏｌ％であるコロイド溶液からなる液晶である。 Another aspect of the present invention is a liquid crystal composed of a colloidal solution containing rod-shaped particles containing the fluoroapatite of the present invention as a main component.
Further, one aspect of the present invention is a liquid crystal composed of a colloidal solution having a volume fraction of rod-shaped particles containing fluoroapatite as a main component of the present invention of 18 to 33 vol%, preferably 20 to 30 vol%.
３．偏光膜
　本発明のもう１つの態様は、本発明のフルオロアパタイトを主成分とする棒状粒子が配向した偏光膜である。
　本発明の配向膜は、本発明のフルオロアパタイトを主成分とする棒状粒子にせん断を印加することにより得ることができる。 3. 3. Another aspect of the polarizing present invention is a polarizing film rod-shaped particles fluoroapatite of the present invention as a main component is oriented.
The alignment film of the present invention can be obtained by applying shear to the rod-shaped particles containing the fluoroapatite of the present invention as a main component.
　本発明の１つの実施態様は、フルオロアパタイトの結晶のｃ軸がせん断方向におおよそ配向している配向膜である。このような配向膜は、具体的には、例えば、液晶相を示すフルオロアパタイトを主成分とする棒状粒子を含むコロイド溶液をガラス等の基板で挟み、一方向にせん断を印加することにより配向膜を得ることができる。 One embodiment of the present invention is an alignment film in which the c-axis of the fluoroapatite crystal is approximately oriented in the shear direction. Specifically, such an alignment film is formed by sandwiching a colloidal solution containing rod-shaped particles containing fluoroapatite as a main component, which exhibits a liquid crystal phase, between substrates such as glass and applying shear in one direction. Can be obtained.
４．フルオロアパタイトを主成分とする棒状粒子の調製方法
　本発明のもう１つの態様は、（１）カルシウムイオンを生成する化合物、リン酸イオンを生成する化合物、フッ素イオンを生成する化合物、及び有機高分子を含む反応溶液を調製する工程、（２）前記反応溶液から析出物を分離して回収する工程を含む、フルオロアパタイトを主成分とする棒状粒子を調製する方法である。
　本発明においては、カルシウムイオンを生成する化合物、リン酸イオンを生成する化合物及びフッ素イオンを生成する化合物とともに、有機高分子を共存させて結晶成長を行うことが重要である。有機高分子が急激な結晶化を抑制することで、液晶性を示すにあたってサイズ分散性が十分に狭い棒状粒子であるフルオロアパタイト結晶の調製が可能となる。 4. Method for preparing rod-shaped particles containing fluoroapatite as a main component Another aspect of the present invention is (1) a compound that produces calcium ions, a compound that produces phosphate ions, a compound that produces fluorine ions, and an organic polymer. This is a method for preparing rod-shaped particles containing fluoroapatite as a main component, which comprises a step of preparing a reaction solution containing the above-mentioned reaction solution and (2) a step of separating and recovering a precipitate from the reaction solution.
In the present invention, it is important to carry out crystal growth in the coexistence of an organic polymer together with a compound that produces calcium ions, a compound that produces phosphate ions, and a compound that produces fluorine ions. By suppressing the rapid crystallization of the organic polymer, it becomes possible to prepare fluoroapatite crystals, which are rod-shaped particles having a sufficiently narrow size dispersibility in exhibiting liquid crystallinity.
　有機高分子としては、酸性有機高分子が好ましく、例えば、ポリアクリル酸、ポリグルタミン酸及びポリアスパラギン酸等のアミノ酸由来のポリマー等が挙げられる。これらの中でも、ポリアクリル酸が好ましい。
　また、有機高分子の種類は１種類でも２種以上を用いてもよい。 As the organic polymer, an acidic organic polymer is preferable, and examples thereof include polymers derived from amino acids such as polyacrylic acid, polyglutamic acid and polyaspartic acid. Of these, polyacrylic acid is preferable.
Further, the type of the organic polymer may be one type or two or more types may be used.
　反応溶液中における有機高分子（好ましくは、ポリアクリル酸）の濃度範囲は、７．２×１０－３重量％以上、好ましくは３．６×１０－２重量％以上であり、１．５×１０－１重量％ぐらい以下が適切である。 The concentration range of the organic polymer (preferably polyacrylic acid) in the reaction solution is 7.2 × 10 -3 % by weight or more, preferably 3.6 × 10-2 % by weight or more, and 1.5 × About 10 -1 % by weight or less is appropriate.
　ポリアクリル酸の平均重量分子量としては、２０００～５０００程度のものを用いることができる。 As the average weight molecular weight of polyacrylic acid, those of about 2000 to 5000 can be used.
　カルシウムイオンを生成する化合物として、塩化カルシウムを好適に用いることができる。
　反応溶液中のカルシウムイオンの濃度は、０．００５ｍｏｌ／Ｌ以上、好ましくは０．０１ｍｏｌ／Ｌ以上であり、０．１ｍｏｌ／Ｌ以下、好ましくは０．０５ｍｏｌ／Ｌ以下である。
　また、カルシウムイオンを生成する化合物としては、１００ｍＭ程度の溶液ができる溶解度を持っていれば、ＣａＸのＸにあたる部分は他のものでも構わない。その例としては、酢酸を挙げることができ、酢酸カルシウム（Ｃａ（ＣＨ３ＣＯＯ）２）も好適に使用することができる。 Calcium chloride can be preferably used as the compound that produces calcium ions.
The concentration of calcium ions in the reaction solution is 0.005 mol / L or more, preferably 0.01 mol / L or more, 0.1 mol / L or less, preferably 0.05 mol / L or less.
Further, as the compound that produces calcium ions, the portion corresponding to X of CaX may be another compound as long as it has a solubility that can form a solution of about 100 mM. As an example, acetic acid can be mentioned, and calcium acetate (Ca (CH 3 COO) 2 ) can also be preferably used.
　リン酸イオンを生成する化合物として、リン酸水素二ナトリウム（Ｎａ２ＨＰＯ４）が好ましく、その水和物（例えば、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ）も好適に使用することができる。
　また、リン酸水素二カリウム（Ｋ2ＨＰＯ４）、リン酸三カリウム（Ｋ３ＰＯ４）、リン酸三ナトリウム（Ｎａ３ＰＯ４）、リン酸三アンモニウム（（ＮＨ４）３ＰＯ４）およびこれらの水和物も使用することが可能である。
　反応溶液中におけるリン酸イオンの濃度は、０．０２ｍｏｌ／Ｌ以上、好ましくは０．０５ｍｏｌ／Ｌ以上、０．１ｍｏｌ／Ｌ以下である。 As a compound that generates a phosphate, disodium hydrogen phosphate (Na 2 HPO 4) is preferred, hydrates thereof (e.g., Na 2 HPO 4 · 12H 2 O) can also be preferably used.
In addition, dipotassium hydrogen phosphate (K 2 HPO 4 ), tripotassium phosphate (K 3 PO 4 ), trisodium phosphate (Na 3 PO 4 ), triammonium phosphate ((NH 4 ) 3 PO 4 ) and These hydrates can also be used.
The concentration of phosphate ions in the reaction solution is 0.02 mol / L or more, preferably 0.05 mol / L or more and 0.1 mol / L or less.
　フッ素イオンを生成する化合物として、フッ化ナトリウム（ＮａＦ）を好適に用いることができる。
　また、フッ化リチウム（ＬｉＦ）およびフッ化カリウム（ＫＦ）も使用することが可能である。
　反応溶液中におけるフッ素イオンの濃度は、０．００５ｍｏｌ／Ｌ以上、好ましくは０．０１ｍｏｌ／Ｌ以上、０．０５ｍｏｌ／Ｌ以下である。 Sodium fluoride (NaF) can be preferably used as the compound that produces fluorine ions.
Lithium fluoride (LiF) and potassium fluoride (KF) can also be used.
The concentration of fluorine ions in the reaction solution is 0.005 mol / L or more, preferably 0.01 mol / L or more and 0.05 mol / L or less.
　反応溶液のｐＨは、通常５～１２であり、好ましくは５～８である。 The pH of the reaction solution is usually 5 to 12, preferably 5 to 8.
　反応溶液の調製は、通常、室温・大気圧下で行われ、撹拌は、５℃程度～８０℃程度、好ましくは、２０℃～６０℃で、数時間～１５０時間程度の間、大気圧下で行われる。 The reaction solution is usually prepared at room temperature and atmospheric pressure, and stirring is carried out at about 5 ° C. to 80 ° C., preferably 20 ° C. to 60 ° C. for several hours to 150 hours under atmospheric pressure. It is done in.
　上記反応溶液を上記のように撹拌することにより、フルオロアパタイトを主成分とする棒状粒子を形成することができる。また、撹拌後に生成する析出物を分離し、フルオロアパタイトを主成分とする棒状粒子を得ることができる。また、析出物は、遠心分離をした後、適量の超純水で洗浄し、真空乾燥を行うことにより回収できるが、これに限定されるものではない。 By stirring the reaction solution as described above, rod-shaped particles containing fluoroapatite as a main component can be formed. In addition, the precipitate formed after stirring can be separated to obtain rod-shaped particles containing fluoroapatite as a main component. Further, the precipitate can be recovered by centrifuging, washing with an appropriate amount of ultrapure water, and vacuum drying, but the present invention is not limited to this.
　以下実施例により本発明をさらに具体的に説明するが、本発明の範囲は下記の実施例に限定されることはない。 The present invention will be described in more detail with reference to the following examples, but the scope of the present invention is not limited to the following examples.
［粒子サイズの測定方法］
　Hitachi High Technologies社製 電界放出型走査型電子顕微鏡 (ＦＥ－ＳＥＭ) S-4700もしくはJEOL製 透過型電子顕微鏡 (ＴＥＭ)ＪＥＭ-２８００で粒子形状を観察し、任意に選択した１００個程度の棒状粒子の長さおよび太（平均粒子径）さを計測して、それらの平均粒子サイズ・分散を求めることにより、粒子サイズの測定を行った。 [Measurement method of particle size]
Observe the particle shape with an electric field emission scanning electron microscope (FE-SEM) S-4700 manufactured by Hitachi High Technologies or a transmission electron microscope (TEM) JEM-2800 manufactured by JEOL, and about 100 rod-shaped particles arbitrarily selected. The particle size was measured by measuring the length and thickness (average particle size) of the particles and determining their average particle size and dispersion.
［実施例１］
　ＣａＣｌ２ ０．０２ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む４００ｍｌの反応溶液を室温で２４時間攪拌し、遠心分離（１００００ｒｐｍ）、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは７８４±９４ｎｍ、平均太さ（幅）は１９３±２７ｎｍ、粒子のアスペクト比は４．１０±０．４９であった。
　Ｘ線回折測定・透過型電子顕微鏡観察から得られた粒子の主成分がフルオロアパタイトであることを確認し、熱重量分析の結果から、９０ｗｔ％のフルオロアパタイトに加えて、５ｗｔ％のポリアクリル酸、５ｗｔ％の水が含まれていることが分かった。
　水分散状態で液晶相の確認を行った。棒状粒子４５ｗｔ％の分散水溶液から液晶に特有の偏光像と流動性が観察された。液晶状態で構造色が観察された。 [Example 1]
CaCl 2 0.02mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at room temperature for 24 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and then vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 784 ± 94 nm, the average thickness (width) was 193 ± 27 nm, and the aspect ratio of the particles was 4.10 ± 0.49. rice field.
It was confirmed that the main component of the particles obtained from X-ray diffraction measurement and transmission electron microscope observation was fluoroapatite, and from the results of thermogravimetric analysis, in addition to 90 wt% fluoroapatite, 5 wt% polyacrylic acid. It was found to contain 5 wt% water.
The liquid crystal phase was confirmed in a water-dispersed state. A polarized image and fluidity peculiar to the liquid crystal display were observed from the dispersed aqueous solution of 45 wt% of rod-shaped particles. Structural color was observed in the liquid crystal state.
［実施例２］
　ＣａＣｌ２ ０．０２ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、　ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む１００ｍｌの反応溶液を室温で２４時間攪拌し、遠心分離（１００００ｒｐｍ）、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは８３０±１１１ｎｍ、平均太さは２２３±３３ｎｍ、粒子のアスペクト比は３．７６±０．５３であった。
　Ｘ線回折測定の結果からフルオロアパタイトであることを確認し、熱重量分析の結果から、９０ｗｔ％のフルオロアパタイトに加えて、５ｗｔ％のポリアクリル酸、５　ｗｔ％の水が含まれていることが分かった。
　水分散状態で液晶性を確認した。液晶状態で構造色が観察された。 [Example 2]
CaCl 2 0.02mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at room temperature for 24 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and then vacuum dried at 60 ° C. to obtain a powder. When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 830 ± 111 nm, the average thickness was 223 ± 33 nm, and the aspect ratio of the particles was 3.76 ± 0.53.
It was confirmed from the result of X-ray diffraction measurement that it was fluoroapatite, and from the result of thermogravimetric analysis, it contained 5 wt% polyacrylic acid and 5 wt% water in addition to 90 wt% fluoroapatite. I found out.
The liquid crystal property was confirmed in the water-dispersed state. Structural color was observed in the liquid crystal state.
［実施例３］
　ＣａＣｌ２ ０．０１ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、　ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）３．６×１０－２ｗｔ％を含む１００ｍｌの反応溶液を室温で４５時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは９３３±１５５ｎｍ、平均太さは１９７±２５ｎｍ、粒子のアスペクト比は４．７９±０．８であった。
　Ｘ線回折測定の結果からフルオロアパタイトであることを確認し、熱重量分析の結果から、９０ｗｔ％のフルオロアパタイトに加えて、５ｗｔ％のポリアクリル酸、５ｗｔ％の水が含まれていることが分かった。
　水分散状態で液晶性を確認した。液晶状態で構造色が観察された。 [Example 3]
CaCl 2 0.01mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 3.6 × 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at room temperature for 45 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 933 ± 155 nm, the average thickness was 197 ± 25 nm, and the aspect ratio of the particles was 4.79 ± 0.8.
It was confirmed from the result of X-ray diffraction measurement that it was fluoroapatite, and from the result of thermogravimetric analysis, it was found that 5 wt% polyacrylic acid and 5 wt% water were contained in addition to 90 wt% fluoroapatite. Do you get it.
The liquid crystal property was confirmed in the water-dispersed state. Structural color was observed in the liquid crystal state.
［実施例４］
　ＣａＣｌ２ ０．０１ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、　ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）３．６×１０－２ｗｔ％を含む４００ｍｌの反応溶液を室温で３０時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは６９９　±９２ｎｍ、平均太さは１２２±１５ｎｍ、粒子のアスペクト比は５．７８±０．６６であった。
　液晶状態で構造色が観察された。 [Example 4]
CaCl 2 0.01mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 3.6 × 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at room temperature for 30 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 699 ± 92 nm, the average thickness was 122 ± 15 nm, and the aspect ratio of the particles was 5.78 ± 0.66.
Structural color was observed in the liquid crystal state.
［実施例５］
　ＣａＣｌ２ ０．０１ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５　ｍｏｌ／Ｌ、　ＮａＦ ０．０１ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む１００ｍｌの反応溶液を６０℃で９６時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは８３７±８３ｎｍ、平均太さは２１２±１７ｎｍ、粒子のアスペクト比は３．９７±０．４５であった。
　Ｘ線回折測定・透過型電子顕微鏡観察結果からフルオロアパタイトであることを確認し、液晶状態で構造色が観察された。 [Example 5]
CaCl 2 0.01mol / L, Na 2 HPO 4 · 12H 2 O 0.05 mol / L, NaF 0.01mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt 100 ml of the reaction solution containing% was stirred at 60 ° C. for 96 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 837 ± 83 nm, the average thickness was 212 ± 17 nm, and the aspect ratio of the particles was 3.97 ± 0.45.
From the results of X-ray diffraction measurement and transmission electron microscope observation, it was confirmed that it was fluoroapatite, and the structural color was observed in the liquid state.
［実施例６］
　ＣａＣｌ２ ０．０２　ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む１００ｍｌの反応溶液を４０℃で１２時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは１１０４±１５０ｎｍ、平均太さは３５７±６５ｎｍ、粒子のアスペクト比は３．１４±０．４３であった。
　Ｘ線回折測定からフルオロアパタイトであることを確認し、熱重量分析の結果から、９０ｗｔ％のフルオロアパタイトに加えて、５ｗｔ％のポリアクリル酸、５ｗｔ％の水が含まれていることが分かった。
　水分散状態で液晶相を示した。 [Example 6]
CaCl 2 0.02 mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt 100 ml of the reaction solution containing% was stirred at 40 ° C. for 12 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 1104 ± 150 nm, the average thickness was 357 ± 65 nm, and the aspect ratio of the particles was 3.14 ± 0.43.
It was confirmed by X-ray diffraction measurement that it was fluoroapatite, and from the results of thermogravimetric analysis, it was found that 5 wt% polyacrylic acid and 5 wt% water were contained in addition to 90 wt% fluoroapatite. ..
The liquid crystal phase was shown in the water-dispersed state.
［実施例７］
　ＣａＣｌ２ ０．０１ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５　ｍｏｌ／Ｌ、ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）３．６×１０－２ｗｔ％を含む１００ｍｌの反応溶液を４０℃で１２時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは７０７　±９５ｎｍ、平均太さは１６６±１９ｎｍ、粒子のアスペクト比は４．２６±０．４９であった。
　Ｘ線回折測定からフルオロアパタイトであることを確認し、熱重量分析の結果から、８９ｗｔ％のフルオロアパタイトに加えて、７ｗｔ％のポリアクリル酸、４ｗｔ％の水が含まれていることが分かった。
　液晶状態で構造色を示した。 [Example 7]
CaCl 2 0.01mol / L, Na 2 HPO 4 · 12H 2 O 0.05 mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 3.6 × 10 -2 wt 100 ml of the reaction solution containing% was stirred at 40 ° C. for 12 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 707 ± 95 nm, the average thickness was 166 ± 19 nm, and the aspect ratio of the particles was 4.26 ± 0.49.
It was confirmed that it was fluoroapatite by X-ray diffraction measurement, and from the result of thermogravimetric analysis, it was found that 7 wt% polyacrylic acid and 4 wt% water were contained in addition to 89 wt% fluoroapatite. ..
The structural color was shown in the liquid crystal state.
［実施例８］
　ＣａＣｌ２ ０．０２　ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む４００ｍｌの反応溶液を１０℃で６０時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは７３３±７０ｎｍ、平均太さは１５３±２４ｎｍ、粒子のアスペクト比は４．８３±０．５２であった。
　液晶状態で構造色を示した。 [Example 8]
CaCl 2 0.02 mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt A 400 ml reaction solution containing% was stirred at 10 ° C. for 60 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 733 ± 70 nm, the average thickness was 153 ± 24 nm, and the aspect ratio of the particles was 4.83 ± 0.52.
The structural color was shown in the liquid crystal state.
［実施例９］
　ＣａＣｌ２ ０．０１６ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０４ｍｏｌ／Ｌ、ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）５．７×１０－２ｗｔ％を含む４００ｍｌの反応溶液を１０℃で２４０時間攪拌し、遠心分離（１００００　ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは９３６±１６１ｎｍ、平均太さは１６３±３７ｎｍ、粒子のアスペクト比は５．８７±０．７３であった。
　液晶状態で構造色を示した。 [Example 9]
CaCl 2 0.016mol / L, Na 2 HPO 4 · 12H 2 O 0.04mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 5.7 × 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at 10 ° C. for 240 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 936 ± 161 nm, the average thickness was 163 ± 37 nm, and the aspect ratio of the particles was 5.87 ± 0.73.
The structural color was shown in the liquid crystal state.
［実施例１０］
　ＣａＣｌ２ ０．０１ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５　ｍｏｌ／Ｌ、ＮａＦ ０．０５ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む１００ｍｌの反応溶液を６０℃で３時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは１００２±７５ｎｍ、平均太さは２９６±２７ｎｍ、粒子のアスペクト比は３．４０±０．３５であった。
　水分散状態で液晶相を示した。 [Example 10]
CaCl 2 0.01mol / L, Na 2 HPO 4 · 12H 2 O 0.05 mol / L, NaF 0.05mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt 100 ml of the reaction solution containing% was stirred at 60 ° C. for 3 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 1002 ± 75 nm, the average thickness was 296 ± 27 nm, and the aspect ratio of the particles was 3.40 ± 0.35.
The liquid crystal phase was shown in the water-dispersed state.
［実施例１１］
　ＣａＣｌ２ ０．０１ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０２ｍｏｌ／Ｌ、ＮａＦ ０．０２５ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む１００ｍｌの反応溶液を６０℃で１８時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは１４４３±１４２ｎｍ、平均太さは６０８±９５ｎｍ、粒子のアスペクト比は２．４１±０．２９であった。
　水分散状態で液晶相を示した。 [Example 11]
CaCl 2 0.01mol / L, Na 2 HPO 4 · 12H 2 O 0.02mol / L, NaF 0.025mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at 60 ° C. for 18 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 1443 ± 142 nm, the average thickness was 608 ± 95 nm, and the aspect ratio of the particles was 2.41 ± 0.29.
The liquid crystal phase was shown in the water-dispersed state.
［実施例１２］
　ＣａＣｌ２ ０．０１ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、ＮａＦ ０．０４ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）３．６×１０－２ｗｔ％を含む４００ｍｌの反応溶液を４０℃で６５時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは３７９±６３ｎｍ、平均太さは９４±１４ｎｍ、粒子のアスペクト比は４．０２±０．３４であった。
　水分散状態で液晶相を示した。 [Example 12]
CaCl 2 0.01mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.04mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 3.6 × 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at 40 ° C. for 65 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 379 ± 63 nm, the average thickness was 94 ± 14 nm, and the aspect ratio of the particles was 4.02 ± 0.34.
The liquid crystal phase was shown in the water-dispersed state.
［実施例１３］
　ＣａＣｌ２ ０．００８ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０４ｍｏｌ／Ｌ、ＮａＦ ０．０３２ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）２．９×１０－２ｗｔ％を含む４００ｍｌの反応溶液を室温で６０時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは２８５±３７ｎｍ、平均太さは６６±８ｎｍ、粒子のアスペクト比は４．３５±０．５３であった。
　水分散状態で液晶相を示した。 [Example 13]
CaCl 2 0.008mol / L, Na 2 HPO 4 · 12H 2 O 0.04mol / L, NaF 0.032mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 2.9 × 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at room temperature for 60 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 285 ± 37 nm, the average thickness was 66 ± 8 nm, and the aspect ratio of the particles was 4.35 ± 0.53.
The liquid crystal phase was shown in the water-dispersed state.
［実施例１４］
　ＣａＣｌ２ ０．０２ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、ＮａＦ ０．０３ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む４００ｍｌの反応溶液を室温で１２時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは２６２±３３ｎｍ、平均太さは６８±８ｎｍ、粒子のアスペクト比は３．９１±０．４８であった。
　水分散状態で液晶相を示した。 [Example 14]
CaCl 2 0.02mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.03mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt % 400 ml of the reaction solution containing the above solution was stirred at room temperature for 12 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 262 ± 33 nm, the average thickness was 68 ± 8 nm, and the aspect ratio of the particles was 3.91 ± 0.48.
The liquid crystal phase was shown in the water-dispersed state.
［実施例１５］
　ＣａＣｌ２ ０．０２ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、ＮａＦ ０．０２５ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む１００ｍｌの反応溶液を６０℃で１６０時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは２３１±３４ｎｍ、平均太さは８３±１４ｎｍ、粒子のアスペクト比は２．８１±０．４０であった。
　水分散状態で液晶相を示した。 [Example 15]
CaCl 2 0.02mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.025mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at 60 ° C. for 160 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 231 ± 34 nm, the average thickness was 83 ± 14 nm, and the aspect ratio of the particles was 2.81 ± 0.40.
The liquid crystal phase was shown in the water-dispersed state.
［実施例１６］
　ＣａＣｌ２ ０．０２ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、ＮａＦ ０．０２５ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）１．１×１０－１ｗｔ％を含む１００ｍｌの反応溶液を６０℃で１６０時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さは１５４±２５ｎｍ、平均太さは５６±９ｎｍ、粒子のアスペクト比は２．７９±０．５０であった。
　Ｘ線回折測定からフルオロアパタイトであることを確認し、熱重量分析の結果から、８８ｗｔ％のフルオロアパタイトに加えて、８ｗｔ％のポリアクリル酸、４ｗｔ％の水が含まれていることが分かった。
　水分散状態で液晶相を示した。 [Example 16]
CaCl 2 0.02mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.025mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 1.1 × 10 -1 wt % 100 ml of the reaction solution containing the above solution was stirred at 60 ° C. for 160 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was 154 ± 25 nm, the average thickness was 56 ± 9 nm, and the aspect ratio of the particles was 2.79 ± 0.50.
It was confirmed by X-ray diffraction measurement that it was fluoroapatite, and from the results of thermogravimetric analysis, it was found that 8 wt% polyacrylic acid and 4 wt% water were contained in addition to 88 wt% fluoroapatite. ..
The liquid crystal phase was shown in the water-dispersed state.
［実施例１７］
　ＣａＣｌ２ ０．０１ｍｏｌ／Ｌ、Ｎａ２ＨＰＯ４・１２Ｈ２Ｏ ０．０５ｍｏｌ／Ｌ、ＮａＦ ０．０２５ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－２ｗｔ％を含む１００ｍｌの反応溶液を６０℃で７２時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さはおおよそ１３０ｎｍ、平均太さはおおよそ４０ｎｍ、粒子のアスペクト比おおよそ３．２であった。
　Ｘ線回折測定の結果から結晶はフルオロアパタイトであることを確認しており、熱重量分析の結果から８５ｗｔ％のフルオロアパタイトに加えて、８ｗｔ％のポリアクリル酸、７ｗｔ％の水が含まれていることが分かった。
　水分散状態で液晶相を示した。 [Example 17]
CaCl 2 0.01mol / L, Na 2 HPO 4 · 12H 2 O 0.05mol / L, NaF 0.025mol / L, polyacrylic acid (weight-average molecular weight: 2,000) 7.2 × 10 -2 wt % 100 ml of the reaction solution containing the above solution was stirred at 60 ° C. for 72 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was about 130 nm, the average thickness was about 40 nm, and the aspect ratio of the particles was about 3.2.
From the result of X-ray diffraction measurement, it was confirmed that the crystal was fluoroapatite, and from the result of thermogravimetric analysis, in addition to 85 wt% fluoroapatite, 8 wt% polyacrylic acid and 7 wt% water were contained. It turned out that there was.
The liquid crystal phase was shown in the water-dispersed state.
［実施例１８］
　ＣａＣｌ２ ０．１ｍｏｌ／Ｌ、Ｋ３ＰＯ４ ０．１　ｍｏｌ／Ｌ、ＫＦ ０．０２ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－１ｗｔ％を含む４００ｍｌの反応溶液を６０℃で７２時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さはおおよそ８０ｎｍ、平均太さはおおよそ２５ｎｍ、粒子のアスペクト比はおおよそ３．２であった。
　水分散状態で液晶相を示した。 [Example 18]
400 ml containing CaCl 2 0.1 mol / L, K 3 PO 4 0.1 mol / L, KF 0.02 mol / L, polyacrylic acid (average weight molecular weight: 2,000) 7.2 × 10 -1 wt% The reaction solution was stirred at 60 ° C. for 72 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was about 80 nm, the average thickness was about 25 nm, and the aspect ratio of the particles was about 3.2.
The liquid crystal phase was shown in the water-dispersed state.
［実施例１９］
　ＣａＣｌ２ ０．１ｍｏｌ／Ｌ、Ｋ３ＰＯ４ ０．１ｍｏｌ／Ｌ、ＫＦ ０．１ｍｏｌ／Ｌ、ポリアクリル酸（平均重量分子量：２，０００）７．２×１０－１ｗｔ％を含む４００ｍｌの反応溶液を６０℃で７２時間攪拌し、遠心分離（１００００ｒｐｍ）したのち、適量の超純水で洗浄したのち、６０℃で真空乾燥して粉体を得た。
　得られた粉体の形状・サイズを電子顕微鏡で見積もったところ、平均長さはおおよそ７５ｎｍ、平均太さはおおよそ３０ｎｍ、粒子のアスペクト比はおおよそ２．５であった。
　水分散状態で液晶相を示した。 [Example 19]
400 ml containing CaCl 2 0.1 mol / L, K 3 PO 4 0.1 mol / L, KF 0.1 mol / L, polyacrylic acid (average weight molecular weight: 2,000) 7.2 × 10 -1 wt% The reaction solution was stirred at 60 ° C. for 72 hours, centrifuged (10000 rpm), washed with an appropriate amount of ultrapure water, and vacuum dried at 60 ° C. to obtain a powder.
When the shape and size of the obtained powder were estimated with an electron microscope, the average length was about 75 nm, the average thickness was about 30 nm, and the aspect ratio of the particles was about 2.5.
The liquid crystal phase was shown in the water-dispersed state.
［実施例２０］
　実施例１で得られたフルオロアパタイト棒状粒子について種々の濃度のコロイド溶液について透過光強度の測定を行った結果を図３に示す。２２ｖｏｌ％から３２ｖｏｌ％まで液晶状態を示す。 [Example 20]
FIG. 3 shows the results of measuring the transmitted light intensity of the fluoroapatite rod-shaped particles obtained in Example 1 for colloidal solutions having various concentrations. The liquid crystal state is shown from 22 vol% to 32 vol%.
［実施例２１］
　実施例１で得られたフルオロアパタイト棒状粒子についてナノ構造を観察した結果を図４（ａ）に、結晶方位解析を行った結果を図４（ｂ）に示す。制限視野電子線回折(図４（ｂ）の透過型電子顕微鏡像丸部分)の結果から、フルオロアパタイトの結晶c 軸と棒状粒子長軸が一致していることが示唆された。 [Example 21]
The results of observing the nanostructures of the fluoroapatite rod-shaped particles obtained in Example 1 are shown in FIG. 4 (a), and the results of crystal orientation analysis are shown in FIG. 4 (b). From the results of selected area electron diffraction (circle part of the transmission electron microscope image in FIG. 4B), it was suggested that the crystal c-axis of fluoroapatite and the long axis of the rod-shaped particles coincide with each other.
［実施例２２］
　実施例１で得られたフルオロアパタイト棒状粒子について透過型電子顕微鏡像と元素分析マッピングの結果を図５に示す。フッ素が棒状粒子に均一に分散しており、フルオロアパタイト粒子であることが示唆される。 [Example 22]
The transmission electron microscope image and the result of elemental analysis mapping for the fluoroapatite rod-shaped particles obtained in Example 1 are shown in FIG. Fluorine is uniformly dispersed in the rod-shaped particles, suggesting that they are fluoroapatite particles.
［実施例２３］
　実施例１で得られたフルオロアパタイト棒状粒子についてＸ線回折の測定結果を図６に示す。
　また、実施例１で得られたフルオロアパタイト棒状粒子について熱重量分析結果を図７に示す。 [Example 23]
FIG. 6 shows the measurement results of X-ray diffraction of the fluoroapatite rod-shaped particles obtained in Example 1.
The thermogravimetric analysis results of the fluoroapatite rod-shaped particles obtained in Example 1 are shown in FIG.
［実施例２４］
　実施例１、実施例４、実施例８で得られたサイズの異なるフルオロアパタイト粉体について５５ｗｔ％の水分散状態、０．０５ｍｍ程度の厚みで透過光強度測定を行った結果を図８に示す（図中、Ａは実施例４、Ｂは実施例８、Ｃは実施例１についての結果である）。それぞれ５７６ｎｍ、４９１ｎｍ、５４２ｎｍ以下の波長の光をほとんど透過しないことが分かった。このように、フルオロアパタイトを主成分とする粒子のサイズを制御することにより、散乱波長を制御することができる。 [Example 24]
FIG. 8 shows the results of measuring the transmitted light intensity of the fluoroapatite powders of different sizes obtained in Examples 1, 4 and 8 in a water-dispersed state of 55 wt% and a thickness of about 0.05 mm. (In the figure, A is the result for Example 4, B is the result for Example 8, and C is the result for Example 1). It was found that light having wavelengths of 576 nm, 491 nm, and 542 nm or less was hardly transmitted, respectively. In this way, the scattering wavelength can be controlled by controlling the size of the particles containing fluoroapatite as a main component.
［実施例２５］
　実施例１で得られた粉体について、液晶相を示す６０ｗｔ％の水分散状態を作製し、ガラス基板にはさんでせん断を印加することで、一軸に配向した膜を作製することが出きた。Ｘ線回折測定から、せん断方向とフルオロアパタイト結晶のｃ軸が一致していることが分かった。 [Example 25]
With respect to the powder obtained in Example 1, a 60 wt% water-dispersed state showing a liquid crystal phase was produced, and shear was applied by sandwiching the powder on a glass substrate to produce a film oriented in one axis. .. From the X-ray diffraction measurement, it was found that the shear direction and the c-axis of the fluoroapatite crystal coincide with each other.
　図９は液晶状態でせん断をかけることにより配向させたフルオロアパタイト棒状粒子の偏光顕微鏡写真（ａ）と極座標プロット（００２反射、２θ＝２５．６°）による配向評価の結果（ｂ）を示す。偏光顕微鏡観察で配向試料を４５度回転させるごとに明暗を繰り返し、一軸配向していることが分かる。また、極座標プロットでは、００２反射の回折強度がせん断方向で強いことから、せん断方向にフルオロアパタイトｃ軸が配向していることが示されている。 FIG. 9 shows a polarizing micrograph (a) of fluoroapatite rod-shaped particles oriented by shearing in a liquid crystal state and a result (b) of orientation evaluation by a polar coordinate plot (002 reflection, 2θ = 25.6 °). By observing with a polarizing microscope, it can be seen that the alignment sample is uniaxially oriented by repeating light and dark every time the sample is rotated by 45 degrees. Further, in the polar coordinate plot, since the diffraction intensity of the 002 reflection is strong in the shear direction, it is shown that the fluoroapatite c-axis is oriented in the shear direction.
［産業上の利用分野］
　本発明のフルオロアパタイトを主成分とする棒状粒子は、構造色を発することができ、散乱波長を制御できることから、特殊インクなどの光学材料に加えて、構成するフルオロアパタイトは生体適合性・機械的強度・化学的安定性を示すため、化粧品などの生活品などへの応用が期待できると考えられる。 [Industrial application field]
Since the rod-shaped particles containing fluoroapatite as a main component of the present invention can emit a structural color and can control the scattering wavelength, the constituent fluoroapatite is biocompatible and mechanical in addition to the optical material such as special ink. Since it exhibits strength and chemical stability, it is expected to be applied to daily necessities such as cosmetics.

Claims (12)

  1. 　フルオロアパタイトを主成分とする棒状粒子。 Rod-shaped particles containing fluoroapatite as the main component.
  2. 　液晶性を示す、請求項１に記載の棒状粒子。 The rod-shaped particles according to claim 1, which exhibit liquid crystallinity.
  3. 　粒子の平均長さが８０ｎｍ～１５００ｎｍであり、粒子の平均太さが２０ｎｍ～８００ｎｍである、請求項１又は２に記載の棒状粒子。 The rod-shaped particles according to claim 1 or 2, wherein the average length of the particles is 80 nm to 1500 nm, and the average thickness of the particles is 20 nm to 800 nm.
  4. 　フルオロアパタイトと有機高分子とが複合化した構造を有する、請求項１～３のいずれか１項に記載の棒状粒子。 The rod-shaped particles according to any one of claims 1 to 3, which have a structure in which fluoroapatite and an organic polymer are composited.
  5. 　請求項１～４のいずれか１項に記載のフルオロアパタイトを主成分とする棒状粒子を含むコロイド溶液。 A colloidal solution containing rod-shaped particles containing fluoroapatite as a main component according to any one of claims 1 to 4.
  6. 　フルオロアパタイトを主成分とする棒状粒子の体積分率が１２～３３ｖｏｌ％である、請求項５に記載のコロイド溶液。 The colloidal solution according to claim 5, wherein the volume fraction of the rod-shaped particles containing fluoroapatite as a main component is 12 to 33 vol%.
  7. 　液晶性を示す請求項６に記載のコロイド溶液。 The colloidal solution according to claim 6, which exhibits liquid crystallinity.
  8. 　請求項１～４のいずれか１項に記載のフルオロアパタイトを主成分とする棒状粒子を含むコロイド溶液からなる液晶。 A liquid crystal display composed of a colloidal solution containing rod-shaped particles containing fluoroapatite as a main component according to any one of claims 1 to 4.
  9. 　前記コロイド溶液中におけるフルオロアパタイトを主成分とする棒状粒子の体積分率が１８～３３ｖｏｌ％である、請求項８に記載の液晶。 The liquid crystal according to claim 8, wherein the volume fraction of the rod-shaped particles containing fluoroapatite as a main component in the colloidal solution is 18 to 33 vol%.
  10. 　請求項１～４のいずれか１項に記載のフルオロアパタイトを主成分とする棒状粒子が配向した偏光膜。 A polarizing film in which rod-shaped particles containing fluoroapatite as a main component are oriented according to any one of claims 1 to 4.
  11. 　前記棒状粒子のｃ軸がせん断方向におおよそ配向している、請求項１０に記載の配向膜。 The alignment film according to claim 10, wherein the c-axis of the rod-shaped particles is substantially oriented in the shear direction.
  12. 　（１）カルシウムイオンを生成する化合物、リン酸イオンを生成する化合物、フッ素イオンを生成する化合物、及び有機高分子を含む反応溶液を調製する工程、（２）前記反応溶液から析出物を分離して回収する工程を含む、フルオロアパタイトを主成分とする棒状粒子を調製する方法。 (1) A step of preparing a reaction solution containing a compound that produces calcium ions, a compound that produces phosphate ions, a compound that produces fluorine ions, and an organic polymer, (2) Separation of precipitates from the reaction solution. A method for preparing rod-shaped particles containing fluoroapatite as a main component, which comprises a step of recovering.
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Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013088722A (en) * 2011-10-20 2013-05-13 Sekisui Chem Co Ltd Polarizing plate using metal plated nanowire
JP2014181160A (en) * 2013-03-21 2014-09-29 Mitsubishi Paper Mills Ltd Method for producing fluorapatite and method for producing fluorapatite particulate

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013088722A (en) * 2011-10-20 2013-05-13 Sekisui Chem Co Ltd Polarizing plate using metal plated nanowire
JP2014181160A (en) * 2013-03-21 2014-09-29 Mitsubishi Paper Mills Ltd Method for producing fluorapatite and method for producing fluorapatite particulate

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
CHEN HAIFENG, SUN KAI, TANG ZHIYONG, LAW ROBERT V., MANSFIELD JOHN F., CZAJKA-JAKUBOWSKA AGATA, CLARKSON BRIAN H.: "Synthesis of Fluorapatite Nanorods and Nanowires by Direct Precipitation from Solution", CRYSTAL GROWTH & DESIGN, ASC WASHINGTON DC, US, vol. 6, no. 6, 1 June 2006 (2006-06-01), US , pages 1504 - 1508, XP055862603, ISSN: 1528-7483, DOI: 10.1021/cg0600086 *
ESCUDERO ALBERTO, CALVO MAURICIO E., RIVERA-FERNÁNDEZ SARA, DE LA FUENTE JESÚS M., OCAÑA MANUEL: "Microwave-Assisted Synthesis of Biocompatible Europium-Doped Calcium Hydroxyapatite and Fluoroapatite Luminescent Nanospindles Functionalized with Poly(acrylic acid)", LANGMUIR, AMERICAN CHEMICAL SOCIETY, US, vol. 29, no. 6, 12 February 2013 (2013-02-12), US , pages 1985 - 1994, XP055862604, ISSN: 0743-7463, DOI: 10.1021/la304534f *

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