JP2001262144A - Liquid crystal interference fine particles and method of producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide liquid crystal interference fine particles that have excellent selectivity in the omnidirectional reflection properties, high fastness to solvents and heat, is useful as a pigment, an ultraviolet reflection agent or an infrared reflection agent and has spherical and elliptical shape, and provide a method of easily producing the same. SOLUTION: A reactive liquid crystal composition that reflects the light in a specific wavelength range is oriented, subjected to the reaction, fixed so that it may reflect the light in a specific range of the wavelength to produce spherical or elliptical particles that can characteristically effect the omnidirectional reflection of the light in a specific range of the wavelength.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to fine particles of a spherical or elliptical spherical shape, which are useful as pigments, ultraviolet reflectors or infrared reflectors and reflect light in a specific wavelength range made of a liquid crystal material. About the method.

[0002]

2. Description of the Related Art Hitherto, pigments which show color changes depending on the viewing angle, called interference pigments, have been developed for applications such as automotive paints, anti-counterfeiting inks, cosmetics, and decorative coatings. Examples of such pigments include U.S. Pat.
No. 010 proposes a method for producing an interference pigment in which inorganic oxides having different optical densities are laminated on an aluminum thin film.

[0003] For example, Japanese Patent Application Laid-Open No. 6-220350 discloses a cholesteric liquid crystal having selective reflection of circularly polarized light.
A method for producing a pigment which has been processed into a film, formed into a film, and then pulverized has been proposed. Also, JP-A-3-1597
No. 88 proposes the use of a cholesteric liquid crystal microcapsule containing carbon powder therein as a thermal transfer ink.In JP-A-11-293251, after dissolving a polymer cholesteric liquid crystal in a solvent, There has been proposed a method of producing fine particles covered with cholesteric liquid crystal by dispersing a coloring substance that absorbs light having a wavelength other than reflected light, and removing the solvent, heat-treating, and cooling.

However, the interference pigments described in US Pat. No. 4,344,010 require the use of hundreds of materials having different optical densities with respect to the substrate material in order to produce a color effect due to light interference in the visible light wavelength region. It must be laminated in nanometer thin layers, and this thickness must be precisely adjusted during the manufacturing process. At that time, in order to accurately control the layer thickness, thin layers are laminated by a vacuum evaporation method or sputtering, but the productivity is poor due to the necessity of a high vacuum, which is not a method advantageous in manufacturing.

On the other hand, in the interference pigment described in JP-A-6-220350, the direction in which the selective reflection of the cholesteric liquid crystal is observed is only in the direction perpendicular to the helical axis of the cholesteric alignment. The reflective property is not obtained, and the pigment is manufactured by the pulverization method. Therefore, the selective reflection surface becomes uneven, and the scattered light increases. Therefore, the pigment obtained by this method has a problem that the reflection characteristics of the cholesteric liquid crystal are weak and the visibility is poor.

The cholesteric liquid crystal microcapsules described in Japanese Patent Application Laid-Open No. 3-159788 are excellent in visibility because the selective reflection of the cholesteric liquid crystal is obtained at all angles of the capsule, but the cholesteric liquid crystal is not fixed because the liquid crystal alignment is not fixed. It is not suitable for use as a pigment since it does not exhibit liquid crystallinity and does not cause selective reflection outside the liquid crystal temperature region of

Further, the coherent fine particles described in JP-A-11-293251 are prepared by using a polymer cholesteric liquid crystal which is in a glassy state at a temperature lower than the liquid crystal transition point, and is rapidly cooled after being in a cholesteric alignment state. Since the orientation is fixed, when the temperature of the obtained fine particles is again equal to or higher than the glass transition point, the orientation state of the liquid crystal is disturbed, and the selective reflection characteristics cannot be obtained. Further, in a solvent in which the used polymer is attacked, dissolution of fine particles and turbidity of the surface occur, so that there has been a problem that a solvent used when producing an ink or a paint is limited. These problems are not limited to the reflection wavelength in the visible light region, but also apply to the reflection wavelength in the ultraviolet light region or the infrared light region.

[0008]

The problem to be solved by the present invention is that it is excellent in selective reflection characteristics in all directions, is robust against solvents and heat, and is useful as a pigment, an ultraviolet reflector or an infrared reflector. It is an object of the present invention to provide liquid crystal interference fine particles having a spherical or elliptical spherical shape and a method for easily producing the same.

[0009]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, after making the reactive liquid crystal composition spherical or elliptical spherical, the liquid crystal was aligned.
By fixing the interference color by reacting the liquid crystal composition, the present inventors have found that it is possible to produce robust liquid crystal interference fine particles having high selective reflection characteristics, and excellent heat resistance, solvent resistance and weather resistance. It was completed.

That is, according to the present invention, (1) a reactive liquid crystal composition that reflects light in a specific wavelength range is oriented and then reacted to be fixed so as to reflect light in a specific wavelength range. A liquid crystal interference fine particles, wherein the shape is spherical or elliptical spherical, and in all directions of the fine particles, the liquid crystal interference fine particles reflect light in a specific wavelength range;

(2) The liquid crystal coherent fine particles according to (1), wherein the specific wavelength range is in the ultraviolet light region, and (3) the liquid crystal coherent fine particles according to (1), wherein the specific wavelength range is in the visible light region. Fine particles and (4) the specific wavelength range is the infrared region (1)
Liquid crystal interference fine particles described in

(5) The liquid crystal interference fine particles according to (3), wherein the liquid crystal interference fine particles include a coloring substance; and (6) the liquid crystal interference fine particles according to (5), wherein the coloring substance is black.

(7) Emulsifying a reactive liquid crystal composition that reflects light in a specific wavelength range by alignment with a solvent incompatible with the liquid crystal composition, and then aligning the liquid crystal material in the liquid crystal composition A method for producing liquid crystal interference fine particles to be reacted in a state where

(8) The method for producing liquid crystal interference fine particles according to (7), wherein the reactive liquid crystal composition containing a coloring substance is used, and (9) the liquid crystal according to (8), wherein the coloring substance is a black material. A method for producing interference fine particles,

(10) The liquid crystal interference fine particles according to any one of (1) to (4) produced by the production method according to the above (7), and (11) the liquid crystal interference fine particles according to the above (8). (5) The liquid crystal interference fine particles according to (5) produced by the production method described above, and (12) The liquid crystal interference fine particles according to (6) produced by the production method described in (9) above. Is included.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. The reactive liquid crystal composition that reflects light in a specific wavelength range by the alignment used in the present invention refers to a liquid crystal composition having a functional group exhibiting reactivity such as polymerization or crosslinking, and has a cholesteric helix alignment in a liquid crystal state. Say what you form.

These are classified into (1) a cholesteric liquid crystal capable of forming a cholesteric helix in the molecule itself, and (B) a chiral compound containing an optically active component for the purpose of introducing a helical structure into a nematic liquid crystal or a smectic C liquid crystal. Nematic liquid crystals or chiral smectic liquid crystal compositions, and (C) lyotropic liquid crystals that form a cholesteric helical orientation when dissolved or dispersed in a diluent.

The reactive liquid crystal composition of the present invention means that, in the case of a cholesteric liquid crystal having a cholesteric helix-forming ability in the molecule itself (A), the molecule itself has a plurality of components such as (B) or (C). In the case of a mixture, a reactive group is introduced into at least one component.

As the cholesteric liquid crystal (A) having the ability to form a cholesteric helix in the molecule itself, there are a low-molecular cholesteric liquid crystal and a high-molecular cholesteric liquid crystal. Examples of low-molecular cholesteric liquid crystals include cholesteryl bromide in which the hydroxyl group of cholesterol is replaced with a halogen atom, cholesteryl halide such as cholesteryl chloride, cholesteryl acetate, which is an ester compound with fatty acids and carbonic acid, cholesteryl benzoate, cholesteryl propionate, and the like. Cholesterol derivatives.

The terminal group of a compound that is originally a nematic liquid crystal, generally called a chiral nematic liquid crystal, has 2
Nematic liquid crystal derivatives having a group having a chiral moiety such as -methylbutyl group, 2-methylbutoxy group or 4-methylhexyl group introduced therein, for example, 4-cyano-4 '-(2-methylbutyl) biphenyl, 4-cyano-4 '-(2-methylbutoxy) biphenyl, 4-cyano-4'-(4-
Methylhexyl) terphenyl, etc.

Furthermore, the compound has a helical structure like a chiral nematic liquid crystal, thereby producing selective reflection characteristics.
Chiral smectic C liquid crystals such as (4-n-heptyloxyphenyl) benzoic acid-2-methylbutyl ester and 4- (4-methylhexyloxy) benzoic acid-4′-n-heptyloxyphenyl ester.

Typical examples of the polymer cholesteric liquid crystal include those having an optically active group in the polymer main chain, such as polyester, polypeptide, polyimide, polyamide, polycarbonate, polyesterimide, cellulose, and the like. For example, polyacrylates, polymethacrylates, polymalonates, polysiloxanes and the like having an optically active group in the side chain can be used.

The nematic liquid crystal of the cholesteric liquid crystal composition used in (B) includes, for example, 4-substituted benzoic acid-4′-substituted phenyl ester, 4-substituted cyclohexanecarboxylic acid-4′-substituted phenyl ester, 4-substituted phenyl ester,
Substituted cyclohexanecarboxylic acid-4′-substituted biphenyl ester, 4- (4-substituted cyclohexanecarbonyloxy) benzoic acid-4′-substituted phenyl ester, 4-
(4-substituted cyclohexyl) benzoic acid-4'-substituted phenyl ester, 4- (4-substituted cyclohexyl) benzoic acid-4'-substituted cyclohexyl ester, 4-substituted-4'-substituted biphenyl, 4-substituted phenyl -4'-substituted cyclohexane, 4-substituted-4'-substituted terphenyl,
4-substituted biphenyl-4'-substituted cyclohexane, 2-
(4-substituted phenyl) -5-substituted pyrimidine and the like.

As the smectic C liquid crystal, for example, 4
-(4-n-hexyloxyphenyl) benzoic acid, 4-
n-octyloxybenzoic acid-4′-n-heptyloxyphenyl ester, 5-n-octyl-2- (4-n
-Octyloxyphenyl) pyrimidine and the like.

The optically active component that can be used here does not need to exhibit liquid crystallinity itself. As such an optically active compound, for example, cholesteryl pelargonic acid having a cholesteryl group as an optically active group, cholesterol stearate, "CB-15" having a 2-methylbutyl group as an optically active group,
"C-15" (all manufactured by BDH), "S1082" (Merck), "CM-19", "CM-20", "C
M "(manufactured by Chisso)," S-811 "having a 1-methylheptyl group as an optically active group (manufactured by Merck),
"CM-21" and "CM-22" (all manufactured by Chisso Corporation) and the like can be mentioned.

Examples of the lyotropic liquid crystal (C) include polymers that exhibit lyotropic liquid crystal properties upon interaction with a diluent, such as cellulose derivatives, polypeptides, polyisocyanates, and aromatic polyamides. Among them, a cellulose derivative is preferable because of its availability. If these are exemplified, methylcellulose, ethylcellulose, cyanoethylcellulose, carbamoylethylcellulose, carboxyethylcellulose, cyanoethyl-carbamoylethylcellulose, cyanoethyl-carboxyethylcellulose,

Examples include carboxyethyl-carbamoylcellulose, hydroxyethylcellulose, ethylhydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, carboxymethylcellulose, cellulose acetate and the like. Here, for example, methylcellulose refers to a cellulose obtained by methyletherifying some or all of the hydroxyl groups of cellulose, and the same applies to other cellulose derivatives. In addition, it is not limited to these exemplified compounds.

The reactive liquid crystal composition which reflects light in a specific wavelength range by the alignment of the present invention may contain a diluent. The type and amount of the diluent are not particularly limited, but need to be within a range for forming a lyotropic liquid crystal exhibiting a cholesteric liquid crystal phase. As the diluent, a general-purpose organic solvent or a liquid compound that can react with heat or active energy rays can be used.

As the reactable liquid compound, acrylic monomers and oligomers, vinyl monomers, vinyl ethers, epoxy compounds, oxetane compounds and the like are preferably used. From the viewpoint of improving the solvent resistance and weather resistance of the liquid crystal interference fine particles after the reaction, the diluent is preferably a reactive diluent that can be reacted by heat or active energy rays.

At least one of the components forming the reactive liquid crystal composition that reflects light in a specific wavelength range by the alignment of the present invention needs to have a reactive group. That is,
In the case where the molecule itself classified into (A) is a cholesteric liquid crystal having a cholesteric helix-forming ability, the liquid crystal molecule itself imparts a helical structure to the nematic liquid crystal or smectic C liquid crystal classified as (B). In the case of a chiral nematic liquid crystal or a chiral smectic liquid crystal composition containing an optically active substance, or in the case of a liotrobic liquid crystal which forms a cholesteric helical orientation in a state of being dissolved or dispersed in a diluent classified as (C). At least one of the components must have a reactive group.

Examples of such a reactive group include an acryl group, a methacryl group, an α-chloroallyl group, a vinyl group,
Examples include a vinyl ether group, an ethoxy group, an oxetanyl group, a cyanate group, an isocyanate group, and an isothiocyanate group. Further, one of the substances having a reactive group is
One has a plurality of the same or different reactive groups,
It is preferably a so-called polyfunctional substance.

In order to introduce these reactive groups into a liquid crystal molecule or an optically active substance to be added for imparting a helical structure to the liquid crystal, a known organic reaction can be used. When a naturally-occurring material such as cholesterol or polysaccharide, for example, cellulose is used, a part or all of the hydroxyl groups contained therein can be provided with the above reactive group via an ether bond, an ester bond, a urethane bond, or the like. .

In the case of a diluent for forming a lyotropic liquid crystal, a material having a reactive group as described above can be selected and used. Further, the reactive liquid crystal composition may contain a reactive solvent or an additive in an amount that does not disturb the cholesteric helix alignment. In the case of the lyotropic liquid crystal classified in the above (C), a diluent is used. In this case, a part or all of the diluent can be replaced with a solvent capable of reacting.

Examples of the solvent that can be reacted include a solvent that can be thermally reacted and a solvent that can be reacted by active energy rays. Examples of such a solvent include a radical polymerization type monomer and a cationic polymerization type monomer. Typical of these are acrylates, methacrylates, maleimides, vinyl ethers, evoxides, oxetanes, maleates, fumarates, crotonates or N-vinylpyrrolidone, or aromatics such as, for example, styrene derivatives, cinnamate. Monomers, N-vinylimidazole and the like. In addition, these are specifically exemplified below, but the present invention is not limited to these exemplified compounds.

As (meth) acrylic compounds, (meth) acrylic acid, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, isooctyl (meth) acrylate, Lauryl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, methoxytriethylene (meth) acrylate, 2-ethoxyethyl (meth) acrylate,

Tetrahydrofurfuryl (meth) acrylate, 3-methoxybutyl (meth) acrylate, ethoxyethoxyethyl (meth) acrylate, phenoxyethyl (meth) acrylate, 1H, 1H, 5H-octafluoropentyl (meth) acrylate, morpho Monofunctional (meth) acrylates such as linoacrylate,

1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, 2-n-butyl-2-ethyl- Bifunctional (meth) acrylates such as 1,3-propanediol di (meth) acrylate, tripropylene glycol di (meth) acrylate, and tetraethylene glycol di (meth) acrylate;

Trifunctional (meth) acrylates such as trimethylolpropane tri (meth) acrylate and pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta ( 4-6 functional (meth) acrylates such as (meth) acrylate and ditrimethylolpropanetetra (meth) acrylate.

In the case of a maleimide-based compound, the maleimide group itself has a function as a photoreaction initiator, so that a photoreaction initiator described later is not required, and a disadvantage that causes yellowing or an extract derived from the photoreaction initiator is caused. Can be removed.

For example, a compound in which a maleimide group is bonded by an aliphatic group is preferable. Specific examples thereof include N-hexylmaleimide and N, N'-4,9-dioxa-1,12-bismaleimide dodecane. Alkyl or alkyl ether maleimide, maleimide acetic acid ethylene glycol ester, maleimide carboxylic acid (poly) alkylene glycol ester such as maleimide acetic acid poly (tetramethylene glycol) ester, carbonate maleimide such as bis (2-maleimidoethyl) carbonate, isophorone Urethane maleimide such as bis-urethane bis (N-ethylmaleimide) and the like;

Examples of the vinyl compound include vinyl acetate, vinyl cinnamate and N-vinyl formaldehyde, and examples of the styrene derivative include styrene and divinylbenzene.

Examples of the vinyl ether compound include methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, hydroxymethyl vinyl ether, 2-hydroxyethyl vinyl ether, chloromethyl vinyl ether, 2-hydroxyethyl vinyl ether, 2-chloroethyl vinyl ether, diethylaminoethyl vinyl ether, and cyclobutyl. Examples include methyl vinyl ether, cyclopentyl vinyl ether, ethylene glycol methyl vinyl ether, diethylene glycol monovinyl ether, and 1,6-hexanediol methyl vinyl ether.

Examples of the compound having an epoxy ring include glycols such as (poly) ethylene glycol, (poly) propylene glycol, (poly) butylene glycol, (poly) tetramethylene glycol, neopentyl glycol, and alkylene oxide modified products thereof. Polyglycidyl ethers, trimethylolpropane, trimethylolethane, glycerin, diglycerin, erythritol, pentaerythritol, sorbitol, 1,4-butanediol, aliphatic polyhydric alcohols such as 1,6-hexanediol, and alkylenes thereof Glycidyl ether synthesized by the reaction of glycidyl ether of an oxide-modified product, hydrogenated bisphenol A or hydrogenated bisphenol F or an alkylene oxide adduct thereof with (methyl) epichlorohydrin Such as ether,

Limonene diepoxide, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-metadioxane Adduct of bis (3,4-epoxycyclohexylmethyl) adipate, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate,

3,4-epoxycyclohexylmethyl-
(Methyl) valerolactone adduct of 3,4-epoxycyclohexanecarboxylate, vinylcyclohexene dioxide, 4-vinylepoxycyclohexane, dipentene diepoxide, dicyclopentadiene diepoxide, ethylenebis (3,4-epoxycyclohexanecarboxylate) And a compound containing an alicyclic ethoxy group such as dicyclopentadiene diepoxide.

Examples of the compound having an oxetane ring include 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene and 1,4-bis [(3-methyl-3-oxetanylmethoxy) methyl ]benzene,
3-methyl-3-glycidyl oxetane, 3-ethyl-
3-glycidyl oxetane, 3-methyl-3-hydroxymethyl oxetane, 3-ethyl-3-hydroxymethyl oxetane, and the like. These can be used alone or as a mixture.

The additives which may be contained in the reactive liquid crystal composition of the present invention include a reaction initiator. Examples of the reaction initiator include various polymerization initiators exhibiting a polymerization initiation function upon irradiation with heat or active energy rays. These can be classified into radical polymerization initiators, cationic polymerization initiators, and anionic polymerization initiators.

Representative radical polymerization initiators that generate radicals by heat include 2,2′-azobisisobutyronitrile, dimethyl-2,2′-azobisisobutyronitrile, Azo compounds such as 2'-azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide), benzoyl peroxide, di-
Peroxides such as t-butyl peroxide, cumene hydroxy peroxide, t-butyl peroxide and 2-ethylhexanoate can be exemplified.

Examples of the cationic polymerization initiator include known protonic acids, metal halides, and stable carbonium ions. Examples of the anionic polymerization initiator include known nucleophilic reagents such as alkali metals, metal hydroxides, and Grignard reagents. Compounds can be used.

Among the photopolymerization initiators, there are radical, cationic and anionic polymerization initiators. Typical examples thereof include radical polymerization initiators such as benzophenone and orthobenzoylbenzoate. Benzophenone-based compounds such as methyl benzoate, 4-benzoyl-4′-methyldiphenylsulfide; diethoxyacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, benzyldimethylketal,
1-hydroxycyclohexyl-phenyl ketone, 2-
Methyl-2-morpholino- (4-thiomethylphenyl)
Acetophenone compounds such as propan-1-one;

Thioxanthone compounds such as isopropylthioxanthone and diethylthioxanthone; phosphine oxide compounds such as mono-acylphosphine oxide and bis-acylphosphine oxide; benzyl, methylphenylglyoxyester, 10-butyl-2-chloroacridone, 2-ethylanthraquinone, 9,10-
Phenanthrene quinone, camphor quinone and the like can be mentioned.

As the cationic photopolymerization initiator, for example, an onium salt such as BF4 of triphenylsulfonium
-Salts, PF 6 -salts, AsF 6 -salts, SbF 6 -salts, iodonium salts having pentafluorophenyl borate as an anion, and iron arene complexes.
Irgacure 261 (manufactured by Ciba Specialty Chemicals), UVI-6990 (manufactured by Union Carbide), Sun Aid SI-60L, SI-
80L and SI-100L (all manufactured by Sanshin Chemical Industry Co., Ltd.). Examples of the photo-anionic polymerization initiator include O-acyloxy oxime.

The mixing ratio of these reaction initiators is not particularly limited, but is preferably in the range of 0.01 to 10% by weight, particularly preferably 0.05 to 5% by weight in the reactive liquid crystal composition. The reactive liquid crystal composition can be reacted after being aligned, and the interference color can be fixed by a method of reacting with an active energy ray or a method of thermally reacting. Applicable. Among them, the method of immobilization using active energy rays is a preferable method because it can be used in any temperature range where the cholesteric liquid crystal exhibits cholesteric alignment.

Other additives include solvents that do not participate in the reaction, inorganic fillers, organic fillers, coupling agents, leveling agents, plasticizers, reaction sensitizers, antioxidants, ultraviolet absorbers, and defoamers. Any known materials such as pigments, dyes and the like can be used without any particular limitation as long as they do not disturb the cholesteric helix orientation.

The particle size of the liquid crystal interference fine particles in the present invention is 0.1 μm to 500 μm, preferably 0.5 μm to 500 μm.
It is 100 μm, more preferably 1 μm to 50 μm.
In the liquid crystal interference fine particles of the present invention, when light in a specific wavelength range is in the visible light region, the purpose is to enhance the visibility of the selectively reflected light of the cholesteric liquid crystal or to obtain fine particles having a complex color with design. And a coloring substance may be contained.

As the coloring substance, any substance can be used as long as it is stable with respect to the reactive liquid crystal composition. There is no particular limitation, but pearl pigment, metal powder, metal fiber, plastic powder, carbon filler, toner, Organic pigments, inorganic pigments and the like can be mentioned. In order to enhance the visibility of the selective reflection light of the cholesteric liquid crystal when adding a coloring substance, a coloring substance that expresses a color by absorbing light such as an organic pigment or an inorganic pigment is preferable.

Examples of the organic pigments herein include azo pigments, polycondensed azo pigments, azo lake pigments, flavanthrone pigments, phthalocyanine pigments, quinacridone pigments, anthraquinone pigments, anthrapyridine pigments, and pyranthrone pigments. Pigments, dioxazine pigments, perylene pigments, perinone pigments, isoindolinone pigments, quinophthalone pigments, thioindigo pigments, indanthrene pigments, and the like.

As the inorganic pigment, for example, zinc white
Titanium oxide, titanium black, antimony white, carbon black, iron black, red iron, mapico yellow, lead red, cadmium yellow, zinc sulfide, lithopone, barium sulfate, lead sulfate,
Examples include barium carbonate, calcium carbonate, lead white, and alumina white.

The liquid crystal interference fine particles containing the coloring substance of the present invention can exhibit a complex color tone depending on the tone of the coloring substance itself and the tone of the light selectively reflected by the cholesteric liquid crystal. When it is desired to visually recognize only the selectively reflected light of the liquid crystal, it is desirable to use a black colored substance or a dark colored substance close to black as the colored substance.

As the coloring substance, the liquid crystal interference fine particles of the present invention can also be used. Cholesteric liquid crystal used for the liquid crystal interference fine particles of the present invention, from its principle, selectively reflects either right-handed or left-handed light,
The intensity of the selectively reflected light is at most 50% of the intensity of the incident light.
Therefore, by using a coloring substance having the same wavelength as the reactive liquid crystal composition and having a different optical rotation, it is possible to obtain liquid crystal interference fine particles having higher selective reflection light intensity.

Further, in order to provide the liquid crystal interference fine particles with a design property having a complex color, a coloring substance such as a pearl pigment, a metal powder, or a metal fiber which expresses a color by reflecting light is preferable. Examples of the pearl pigment mentioned here include natural pearl essence, basic lead carbonate, bismuth chloride oxide, lead acid arsenate, and metal oxide-coated mica. As metal powder, granular or flaked aluminum powder, bronze powder, stainless steel powder, nickel powder,
Gold powder, gold and silver nanoparticles, and the like. In addition, examples of the metal fiber include an aluminum filler and a nickel filler.

The amount of the coloring substance used in the reactive liquid crystal composition varies depending on the type and size of the coloring substance, but is usually 0.1 to 10% with respect to the reactive liquid crystal composition.
The range is from 01 to 50% by weight, preferably from 0.1 to 30% by weight. Further, as a method of dispersing the coloring substance in the reactive liquid crystal composition, any known and commonly used method can be used, and typical examples include a dispersion method by stirring, a dispersion method by ultrasonic waves, a ball mill, and the like. And a dispersing method using a mixer.

The spherical or oval spherical liquid crystal interference fine particles of the present invention are prepared by dispersing the above-mentioned reactive liquid crystal composition in an incompatible solvent and emulsifying the same, and then performing alignment and reaction in a temperature region where cholesteric alignment is exhibited. It can be manufactured by performing.

The solvent incompatible with the reactive liquid crystal composition is generally water when the reactive liquid crystal composition is hydrophobic. When the reactive liquid crystalline composition is hydrophilic,
Aliphatic hydrocarbon solvents such as hexane, heptane and cyclohexane, aromatic solvents such as toluene and xylene, ester solvents such as ethyl acetate and butyl acetate, diethyl ether, methyl ethyl ether, di-n-propyl ether, Ether solvents such as isopropyl ether, halogenated hydrocarbon solvents such as chloroform and dichloromethane, and ketone solvents such as methyl isobutyl ketone.

Examples of the method for producing an emulsion include a method in which a reactive liquid crystal composition is heated to be in a solution state, and then dropped into an incompatible solvent with stirring, and a method in which the reactive liquid crystal composition is in a solution state. A method in which an incompatible solvent is added thereto while stirring to transfer and emulsify. Further, in the step of making the shape spherical or elliptical spherical, additives such as a dispersant and an emulsifier can be appropriately used in order to make the emulsion exist in a stable state in the solvent.

Examples of such dispersants and emulsifiers include
Nonionic activators such as polyoxyethylene alkyl phenol, polyoxyethylene styryl phenol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and various anionic activators such as various sulfonates, sulfates, and phosphates; Organic polymer compounds such as carboxymethylcellulose and polyvinyl alcohol; saccharide derivatives such as xanthan gum, guar gum, and sodium alginate;

The reactive liquid crystal composition used in the present invention comprises:
In order to spontaneously form a cholesteric helical orientation in the liquid crystal state, the cholesteric liquid crystal is selectively reflected after leaving it in a spherical shape or an elliptical sphere, but in order to reduce the time required for alignment, In the process, it is also an effective means to stir with a strong stirrer such as a homogenizer or to apply pressure to a long thin tube to feed it by applying a shear force or to promote orientation such as applying an electric or magnetic field. .

As a reaction method for fixing the selectively reflected light of the cholesteric liquid crystal, a thermal reaction method, a reaction method using an active energy ray, or the like can be applied. However, in the thermal reaction method, the cholesteric liquid crystal is selectively reflected by the cholesteric liquid crystal because the temperature range in which the cholesteric liquid crystal alignment is formed differs depending on the type of liquid crystal used, the type of solvent and additives, and their composition. Must be performed at various temperatures of the cholesteric liquid crystal alignment state in order to fix
The most preferred is an immobilization method by the reaction of active energy rays.

The active energy rays used here include ultraviolet rays, electron rays, α rays, β rays, γ rays, visible rays, sunlight and the like. Among them, the use of ultraviolet rays, electron beams or visible rays is preferred, and the use of ultraviolet rays is particularly recommended for economic reasons. Examples of the ultraviolet light source include a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, a chemical lamp, a black light lamp, a mercury-xenon lamp, an excimer lamp, a short arc lamp, a helium / cadmium laser, and argon. Laser and sunlight.

As a method for producing the liquid crystal interference fine particles of the present invention, other than the above-mentioned methods, any conventional method may be used as long as the shape finally becomes spherical or elliptical spherical. Another such method is a microencapsulation method.

The microcapsule can be produced by adding an electrolyte or an organic solvent to the polymer solution to reduce the solubility of the polymer and cause phase separation, a coacervation method, a method of combining a hydrophobic monomer and a hydrophilic monomer. An interfacial polymerization method in which a W / O or O / W emulsion is produced and a polymerization reaction is performed at the interface to encapsulate the emulsion, and polymerization conditions are set so that the polymer generated at the interface of the emulsion uniformly surrounds the surface layer of the emulsion. In-situ (in-situ) polymerization method in which a monomer or a polymerization catalyst is supplied from either the inner phase or the outer phase to encapsulate the liquid crystal composition, and the surface of the liquid crystal composition whose size has been previously adjusted by an orifice is encapsulated with a coating material. And an in-liquid cured film method (orifice method) in which the film is cured in a curing liquid.

As a method other than the microencapsulation method, a spray drying method of spraying and reacting a liquid crystalline composition under irradiation of light or energy rays or under heating can be mentioned. The liquid crystal interference fine particles of the present invention have a unique color effect of cholesteric liquid crystal when the selective reflection wide range is in the visible light region. Because these are spherical or elliptical spherical,
Because it develops color in all directions and is excellent in visibility, when printing or applying them as inks or paints, it is not necessary to devise measures such as aligning the orientation of dispersed liquid crystal pigments, and by the same means as conventional inorganic and organic pigments , Paints, inks, plastic coloring, cosmetics, etc.

Further, it can be used for decorative paints and decorative inks, that is, for forgery prevention applications, by utilizing the unique coloring effect. If you do not include colored particles inside,
When a colored substance is included by making it into an ink or paint on a colored film or paint and printing or applying it, a unique coloration is made by making it into an ink or paint and printing or applying it on a colorless or transparent substrate It is possible to obtain a printed material or a coating film having an effect. Further, it can be used as a color filter for a liquid crystal display because of its characteristic of reflecting only a specific wavelength.

When the liquid crystal interference fine particles of the present invention have a selective reflection wide range in the ultraviolet region, ultraviolet light is further reflected as an ultraviolet ray preventing material such as a paint for the outer wall of cosmetics and buildings, and a clear paint for automobiles. Utilizing the advantage of transparent fine particles that do not color the particles themselves because visible light is transmitted,
It can be used for ultraviolet protection films and the like that require transparency, such as automobile and agricultural greenhouses. Similarly, when the selective reflection light is in the infrared light region, it takes advantage of the advantage of being transparent fine particles that reflect infrared light but transmit visible light and thus do not color the particles themselves, and are used for building and automobile glass. Can be used for heat insulating films and the like.

[0075]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and the like, but the present invention is not limited to the following Examples.

(Example 1) 5.0 g of a polymerizable liquid crystal compound represented by the formula 1, 5.0 g of a polymerizable liquid crystal compound represented by the formula 2,
3.0 g of an optically active compound represented by the formula: Irgacure 651 (manufactured by Ciba Specialty Chemicals) as a photoinitiator
0.26 g was heated and dissolved at 50 ° C.

[0077]

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The obtained solution was dropped into 1000 ml of a 0.15% aqueous polyvinyl alcohol solution under stirring at a rotational speed of 1500 / min using a homomixer, and the mixture was stirred for 5 minutes to prepare an emulsion. The emulsion was allowed to stand under ice cooling for 10 minutes, and then subjected to ultraviolet irradiation for 3 minutes with an irradiation distance of 20 cm using a 1500 W high-pressure mercury lamp. When this solution was filtered and dried, the average particle size was about 20.
11.0 g of translucent spherical fine particles of 0 μm were obtained.

The fine particles were placed on a black base and observed with an incident-light stereomicroscope. As a result, the particles were spherical and exhibited a strong blue interference color. 1 g of the obtained fine particles was dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 was dissolved as a photoinitiator, and the solution was applied on a slide glass and cured by ultraviolet rays to prepare a coating film of fine particles. When the reflection wavelength of this coating film was measured at an incident angle of light of -45 °, the center wavelength of the reflection wavelength was about 450 n at a measurement angle of 30 °.
m and 430 nm at a measurement angle of 60 °.

(Example 2) Fine particles were produced in the same manner as in Example 1 except that the amount of the optically active compound represented by the formula 3 was changed to 2.5 g. 11.0 g of translucent spherical fine particles having an average particle size of about 200 μm were obtained. When the obtained fine particles were placed on a black base and observed with an incident-light stereomicroscope, the particles were spherical and exhibited a strong green interference color. 1 g of the fine particles were dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 as a photoinitiator was dissolved. The solution was applied on a slide glass and cured by ultraviolet rays to prepare a coating film of the fine particles. When the reflection wavelength of this coating film was measured at an incident angle of light of -45 °, the center wavelength of the reflection wavelength was about 530 nm at a measurement angle of 30 °, and 500 n at a measurement angle of 60 °.
m.

(Example 3) Fine particles were prepared in the same manner as in Example 1 except that the amount of the optically active compound represented by the formula 3 was changed to 2.0 g. Obtained. The average particle size of the fine particles is about 20
It was 0 μm. When the obtained fine particles were placed on a black base and observed with an incident-light stereomicroscope, the particles were spherical and exhibited a strong red interference color. 1 g of the obtained fine particles were dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and Irgacure 65 was used as a photoinitiator.
1 was dissolved in 0.06 g, applied on a slide glass, and cured by ultraviolet rays to prepare a coating film of fine particles. When the reflection wavelength of this coating film was measured at an incident angle of light of -45 °, a measurement angle of 3
At 0 °, the center wavelength of the reflection wavelength is about 610 nm, and the measurement angle is 6
At 0 °, it was 570 nm.

(Example 4) 5.0 g of a polymerizable liquid crystal compound represented by the formula 1, 5.0 g of a polymerizable liquid crystal compound represented by the formula 2, and
3.0 g of an optically active compound represented by the formula: Irgacure 651 (manufactured by Ciba Specialty Chemicals) as a photoinitiator
0.26 g was heated and dissolved at 50 ° C. Carbon black (MA-7 manufactured by Mitsubishi Chemical) is added to the liquid crystal mixture in the form of a solution.
0.026 g was added and ultrasonic dispersion was performed for 5 minutes. The obtained solution was stirred with a homomixer at a rotational speed of 1500 / min.
The mixture was dropped into 00 ml, and stirring was continued for 5 minutes to prepare an emulsion.

When this emulsion was left under ice cooling, a bluish color was formed after 10 minutes. This emulsion was irradiated with ultraviolet light for 3 minutes at an irradiation distance of 20 cm using a high-pressure mercury lamp of 1500 W. The solution was filtered and dried to obtain 11.0 g of spherical fine particles having strong blue circularly polarized selectively reflected light. The average particle size of the fine particles was about 200 μm. 1 g of the fine particles were dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 as a photoinitiator was dissolved. The solution was applied on a slide glass and cured by ultraviolet rays to prepare a coating film of the fine particles. When the reflection wavelength of this coating film was measured at an incident angle of light of -45 °, the central wavelength of the reflection wavelength was about 450 nm at a measurement angle of 30 ° and 430 nm at a measurement angle of 60 °.

Example 5 Green spherical fine particles 11.0 g were obtained in the same manner as in Example 4 except that the amount of the optically active compound represented by the formula 3 was changed to 2.5 g. The obtained fine particles had strong green circularly polarized selectively reflected light and had an average particle size of about 200 μm. 1 g of the obtained fine particles was dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 was dissolved as a photoinitiator, and the solution was applied on a slide glass and cured by ultraviolet rays to prepare a coating film of fine particles. When the reflection wavelength of this coating film was measured at an incident angle of light of -45 °, the measurement angle was 30 °.
In, the center wavelength of the reflection wavelength is about 530 nm, and the measurement angle is 60 °
Was 500 nm.

(Example 6) Red spherical fine particles (11.0 g) were obtained in the same manner as in Example 4 except that the amount of the optically active compound represented by the formula (3) was changed to 2.0 g. The obtained fine particles had strong red circularly polarized selectively reflected light and had an average particle size of about 200 μm. 1 g of the fine particles was dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 was used as a photoinitiator.
g, melted, coated on a slide glass, and cured by ultraviolet light to form a coating film of fine particles. When the reflection wavelength of this coating film was measured at an incident angle of light of -45 °, the central wavelength of the reflection wavelength was about 610 nm at a measurement angle of 30 °, and 57 nm at a measurement angle of 60 °.
It was 0 nm.

(Production Example 1) Production Example of Polymerizable Ethyl Cellulose Ethyl cellulose in which 2.6 hydroxyl groups were ethylated on average out of three hydroxyl groups of glucose which is a constitutional unit of cellulose (number-average molecular weight = about 15,000). , Hercules) 3600 g in tetrahydrofuran 600 ml
And 6.1 g of 2-isocyanatoethyl methacrylate and 0.036 g of tin octylate were added.
Stirred at C for 7 hours.

After distilling off tetrahydrofuran from the reaction solution under reduced pressure, it was poured into 1000 ml of methanol to obtain a white precipitate. The white precipitate was filtered, heated and dried, and 28.0 g of an ethyl cellulose derivative in which 75% of the hydroxyl groups remaining in the raw material ethyl cellulose were urethanized with 2-isocyanatoethyl methacrylate (hereinafter, referred to as MOI conversion ratio) as a white solid. Obtained.

Example 7 In a mixed monomer solution of 1.0 g of trimethylolpropane triacrylate and 4.0 g of acrylic acid, 5.0 g of the polymerizable ethyl cellulose having a MOI ratio of 75% obtained in Production Example 1 and a photoinitiator Irgacure 651 (manufactured by Ciba Specialty Chemicals) 0.2
6 g were dissolved. 0.026 g of carbon black (MA-7 manufactured by Mitsubishi Chemical Corporation) was added to the liquid crystal mixture in the form of a solution.
Ultrasonic dispersion was performed for 5 minutes. The obtained solution was stirred with a homomixer at a rotation speed of 5000 / min under stirring of 0.25%.
Hydroxyethyl cellulose saturated saline solution 1000
The mixture was added dropwise to the mixture and stirred for 5 minutes to prepare an emulsion.

When this emulsion was left under ice cooling for 24 hours, a bluish color was developed. An irradiation distance of 2 mm was applied to this emulsion using a 1500 W high-pressure mercury lamp.
Ultraviolet irradiation was performed at 0 cm for 3 minutes. When the solution subjected to the ultraviolet irradiation was filtered and dried, 9.3 g of spherical fine particles having strong blue circularly selectively reflected light were obtained.

The obtained fine particles have an average particle size of about 150 μm.
Met. 1 g of the obtained fine particles was dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 was dissolved as a photoinitiator, and the solution was applied on a slide glass and cured by ultraviolet rays to prepare a coating film of fine particles. When the reflection wavelength of this coating film was measured at an incident angle of light of -45 °, the central wavelength of the reflection wavelength was about 420 nm at a measurement angle of 0 ° (perpendicular to the coating film), and 400 nm at a measurement angle of 30 °. Was.

(Embodiment 8) Production Example 1 in Embodiment 7
In the same manner as in Example 7, except that the amount of the polymerizable ethyl cellulose having a MOI ratio of 75% obtained in the above was changed to 4.8 g, 9.0 g of green spherical fine particles were obtained. The obtained fine particles had strong circularly polarized light selectively reflected by green light, and had an average particle size of about 150 μm. 1 g of the obtained fine particles was dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 was dissolved as a photoinitiator, and the solution was applied on a slide glass and cured by ultraviolet rays to prepare a coating film of fine particles. When the reflection wavelength of this coating film was measured at an incident angle of light of -45 °, the measurement angle was 30 °.
The center wavelength of the reflection wavelength is about 450 nm, and the measurement angle is 60 °
Was 420 nm.

(Example 9) In 100 ml of ethyl acetate,
1 g of the fine particles obtained in Examples 4 to 6 was added and left at room temperature for one week, but no change was observed in the circularly polarized light selectively reflected light of the fine particles. Compared with Comparative Example 1, the spherical liquid crystal interference fine particles of the present invention have no solvent swelling or surface deterioration and exhibit excellent solvent resistance.

(Example 10) In 100 ml of toluene,
1 g of the fine particles obtained in Examples 7 and 8 was added and left at room temperature for one week, but no change was observed in the circularly polarized light selectively reflected light of the fine particles. Compared with Comparative Example 1, the spherical liquid crystal interference fine particles of the present invention have no solvent swelling or surface deterioration and exhibit excellent solvent resistance.

(Example 11) 65.0 g of acrylic resin Acrydic 47-712 (manufactured by Dainippon Ink and Chemicals) for baking paint and melamine resin Super Beckamine L-117-60 (manufactured by Dainippon Ink and Chemicals) for baking paint ) 13.6 g was dissolved in 16.3 g of a mixed solvent of xylene: n-butanol = 3: 1. Into this resin solution, 5.0 g of the green spherical fine particles obtained in Example 7 were added and dispersed by stirring. The viscosity of the obtained fine particle-dispersed resin solution was adjusted to 18 seconds with a Ford cup using a mixed solution of Solvesso # 100: xylene: ethyl acetate: n-butanol = 4: 3: 2: 1, and baked. Acrylic paint.

This paint was applied on a steel plate which had been subjected to black baking using an applicator to obtain a green paint film. When this coating film was baked at 120 ° C. for 20 minutes, no change was observed in the film, and the coating film remained green.
Using the obtained coating film, a weather resistance test equivalent to two years of exposure to Florida was performed using an accelerated weather resistance tester (I-Super; manufactured by Suga Test Instruments). As a result, no change was observed in the reflection wavelength of the coated plate, and excellent weather resistance was exhibited.

Comparative Example 1 A mixed solution of 71 g of methyl biphenyldicarboxylate, 7.35 g of (R)-(-)-1,3-butanediol, and 23.1 g of 3-methyl-1,5-pentanediol was added to a mixed solution of orthomethyl. 0.3 g of tetraisopropyl titanate was subjected to a dehydration esterification reaction at 210 ° C. for 2 hours under a nitrogen stream. GP of the obtained polyester
The molecular weight by C analysis was about 4500 in number average molecular weight and about 5700 in weight average molecular weight in terms of polystyrene.

100 g of the polyester obtained was 900 g
Was dissolved in N-methylpyrrolidone to prepare a 10% concentration polymer solution. 0.2 g of carbon black (MA-7, manufactured by Mitsubishi Chemical Corporation) was added to this solution, and the mixture was stirred and dispersed.
When this solution was treated at 130 ° C. using a spray dryer, fine particles 80 having blue circularly polarized light selective reflection were obtained.
g was obtained. The average particle diameter of the obtained fine particles is about 300 μm,
The central wavelength of the selectively reflected light was about 480 nm.

When 1 g of the fine particles was added to 100 ml of ethyl acetate, swelling of the particles was observed, and at the same time, the surface of the particles became white, and the circularly polarized selectively reflected light became invisible. The obtained blue fine particles were dispersed in an acryl-melamine paint in the same manner as in Example 11, and a coating film was formed in the same manner. As a result, the particles became cloudy and the blue color was no longer visible, and a weather resistance test could be performed. Did not.

(Example 12) Fine particles were produced in the same manner as in Example 1 except that the amount of the optically active compound represented by the formula 3 was changed to 3.5 g. Obtained. The average particle size of the fine particles is about 200μ
m. The microparticles were placed on a black base and observed with an epi-illumination stereomicroscope. As a result, they were spherical transparent microparticles.

One gram of the obtained fine particles was dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 was used as a photoinitiator.
It was melted, coated on a slide glass, and cured by ultraviolet rays to prepare a fine particle coating film. When the reflection wavelength of this coating film was measured, the center of the reflection wavelength was about 350 nm, and the obtained coating film was a coating film reflecting ultraviolet light.

(Example 13) Fine particles were produced in the same manner as in Example 1 except that the amount of the optically active compound represented by the formula 3 was changed to 0.8 g, and 9.5 g of translucent spherical fine particles.
I got The average particle size of the fine particles was about 200 μm. The microparticles were placed on a black base and observed with an epi-illumination stereomicroscope. As a result, they were spherical transparent microparticles. 1 g of the obtained fine particles was dispersed in 3 g of ethylene oxide-modified trimethylolpropane triacrylate, and 0.06 g of Irgacure 651 was dissolved as a photoinitiator, and the solution was applied on a slide glass and cured by ultraviolet rays to prepare a coating film of fine particles. When the reflection wavelength of this coating film was measured, the center of the reflection wavelength was about 800 nm, and the obtained coating film was a coating film reflecting infrared light.

[0102]

The liquid crystal interference fine particles of the present invention are excellent in selective reflection characteristics in all directions because they are spherical or elliptical spherical, and are robust against solvents and heat because they are polymerized and fixed. Further, the method for producing liquid crystal interference fine particles of the present invention can be easily mass-produced,
Control of particle size is also easy.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 19/36 C09K 19/36 19/38 19/38 (72) Inventor Katsuharu Takahashi 5-Someino, Sakura-shi 21-2 F-term (reference) 4H027 BA02 BA06 BA11 BE06 BE07 CC08

Claims (12)

[Claims] Claims: 1. A reactive liquid crystal composition that reflects light in a specific wavelength range is oriented and then reacted to be fixed to reflect light in a specific wavelength range. Wherein the liquid crystal interference fine particles reflect light in a specific wavelength range in all directions of the fine particles. 2. The liquid crystal interference fine particles according to claim 1, wherein the specific wavelength range is an ultraviolet light region. 3. The liquid crystal interference fine particles according to claim 1, wherein the specific wavelength range is a visible light region. 4. The liquid crystal interference fine particles according to claim 1, wherein the specific wavelength range is an infrared light region. 5. The liquid crystal interference fine particles according to claim 3, wherein the liquid crystal interference fine particles include a coloring substance. 6. The liquid crystal interference fine particles according to claim 5, wherein the coloring substance is black. 7. Emulsifying a reactive liquid crystal composition that reflects light in a specific wavelength range by orientation and a solvent incompatible with the liquid crystal composition, and then aligning the liquid crystal material in the liquid crystal composition. For producing liquid crystal interference fine particles which are reacted in an inclined state. 8. The method for producing liquid crystal interference fine particles according to claim 7, wherein a reactive liquid crystal composition containing a coloring substance is used. 9. The method for producing liquid crystal interference fine particles according to claim 8, wherein the coloring substance is a black material. 10. The liquid crystal interference fine particles according to claim 1, which is produced by the production method according to claim 7. 11. The liquid crystal interference fine particles according to claim 5, produced by the production method according to claim 8. 12. The liquid crystal interference fine particles according to claim 6, produced by the production method according to claim 9.