JP2008255316A - Multilayer structure nonspherical particle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multilayer structure nonspherical particle which can selectively transmit or reflect a wide range of specific wavelength light, and a method of producing the same with ease. <P>SOLUTION: The multilayer structure nonspherical particle has a structure having a center layer (L0) as a core and at least two layers (Ln) concentrically laminated thereon with respect to the center of the core, where all the differences of a refractive index between adjacent layers are each 0.01-1.5 and at least one layer of the center layer (L0) and the layers (Ln) is a metal oxide layer (M). The method of producing the particle involves at least two selected from the group consisting of (10) a production process using pulse laser irradiation, (20) a production process using a gaseous metal compound, (30) a production process using a sol-gel method and a double micell layer and (40) a production process using the sol-gel method, repeat of at least two of them or repeat of at least one of them, or (50) a production process using an opposite charge. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to multilayered non-spherical particles.

Conventionally, as a particle having a multi-layer structure, for example, a multi-layer structure in which two or more polymer layers satisfying a relationship in which the difference in interfacial tension with respect to water exceeds 0.1 (mN / m) is laminated concentrically with four or more layers. A multilayer structure polymer particle (for example, see Patent Document 2) composed of molecular fine particles (for example, see Patent Document 1), a crosslinked methyl methacrylate layer, a crosslinked elastic alkyl acrylate layer, and a hard thermoplastic methyl methacrylate layer is disclosed.
JP 2004-35785 A JP 2004-352837 A

However, conventional particles have a problem that light of a specific wavelength cannot be selectively transmitted or reflected over a wide range.
An object of the present invention is to provide a multilayered non-spherical particle capable of selectively transmitting or reflecting a wide range of light having a specific wavelength. Another object of the present invention is to provide a method for easily producing the multilayered non-spherical particles.

  The multi-layer structure non-spherical particles of the present invention are characterized by having a structure in which two or more layers (Ln) are stacked concentrically with the center layer (L0) as a core and adjacent to the center of the core. All of the refractive index differences (25 ° C.) are 0.01 to 1.5, and at least one of the central layer (L0) and the layer (Ln) is a metal oxide layer (M). .

  The characteristics of the method for producing a multilayered non-spherical particle in which at least one of the central layer (L0) and the layer (Ln) of the present invention is a metal oxide layer (M) are the production steps (10), (20), The gist is that it includes at least two types selected from the group consisting of (30) and (40), at least two types of repetition, or at least one type of repetition.

In the dispersion liquid (D0) in which the central layer (L0) is dispersed or in the dispersion liquid (Dn) in which the multilayer particles are dispersed, a lump of resin or metal oxide is placed, and this lump is irradiated with a pulse laser to form fine particles. A production step of obtaining a multilayer structure non-spherical particle by forming a resin layer (R) or a metal oxide layer (M) on the surface of the central layer (L0) or the multilayer particle to obtain a multilayer particle dispersion. 10);

The central layer (L0) or multilayer particle having a reactive group (a) or multilayer particle having a reactive group (a) on the surface and a gaseous metal compound are reacted by heating. After forming a metal compound layer on the surface of the metal to obtain metal compound layer particles, unreacted gaseous metal compound is removed, and the metal compound layer particles and water vapor are reacted to form the metal compound layer as a metal oxide layer (M A production step (20) for obtaining multilayer non-spherical particles by obtaining multilayer particles by changing to

The surface of the dispersion layer (D0) in which the central layer (L0) composed of a resin having active hydrogen is dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31) or a resin layer having active hydrogen A metal alkoxide is added to a dispersion (Dn) in which multi-layered particles are dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31), and a central layer (L0) is obtained by a sol-gel method. Or a step of forming a metal oxide layer on the surface of the multilayer particles to obtain a multilayer particle dispersion (31);

A central layer (L0) composed of a cationic or anionic reactive surfactant (S1) copolymerizable with the resin precursor (m) and multilayer particles or metal oxide having a metal oxide layer on the surface In a dispersion containing
After adding a reactive surfactant (S2) copolymerizable with the resin precursor (m) and having an ionicity opposite to that of the reactive surfactant (S1), and the resin precursor (m) ,
The reactive surfactant (S1), the reactive surfactant (S2), and the resin precursor (m) are copolymerized to form a resin layer on the surface of the multilayer particle or the central layer (L0). Isolating multilayer particles after obtaining the liquid (32);

Contains a cationic or anionic reactive surfactant (S1) copolymerizable with the resin precursor (m) and a multilayer layer having a resin layer on the surface or a central layer (L0) composed of a resin Into the dispersion
After adding a reactive surfactant (S2) copolymerizable with the resin precursor (m) and having an ionicity opposite to that of the reactive surfactant (S1), and the resin precursor (m) ,
The reactive surfactant (S1), the reactive surfactant (S2), and the resin precursor (m) are copolymerized to form a resin layer on the surface of the multilayer particle or the central layer (L0). Isolating multilayer particles after obtaining the liquid (33); and

Dispersion (D0) in which a central layer (L0) composed of a metal oxide having active hydrogen is dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31) or metal oxidation having active hydrogen A metal alkoxide is added to a dispersion liquid (Dn) in which multilayer particles whose surface is composed of a product is dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31), and a sol-gel method is used. Step (34) of obtaining a multilayer particle dispersion by forming a metal oxide layer on the surface of the central layer (L0) or multilayer particle
A production step (30) for obtaining multi-layered non-spherical particles by containing at least one selected from:

It has a dispersion (D0) or active hydrogen in which a central layer (L0) composed of a resin or metal oxide having active hydrogen is dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31). A metal alkoxide is added to a dispersion liquid (Dn) in which multilayer particles whose surface is composed of a resin layer or a metal oxide layer are dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31). A production process (40) for forming a multilayer particle dispersion by forming a metal oxide layer on the surface of the central layer (L0) or the multilayer particles by a sol-gel method;

Further, the particle size is centered in the dispersion (D0) in which the central layer (L0) having the charge (q) is dispersed on the surface or the dispersion (Dn) in which the multilayer particles having the charge (q) are dispersed on the surface. By adding particles (P0) having a charge (r) opposite to the particle size (L0) of the layer (L0) or multilayer particles, the central layer (L0) or multilayer particles After forming a layer composed of particles (P0) on the surface of to obtain a multilayer particle dispersion,
The gist of the present invention is that it includes a production step (50) in which the above operation is repeated to obtain multilayered non-spherical particles in which at least one of the central layer (L0) and the layer (Ln) is a metal oxide layer (M).

The multilayer non-spherical particles of the present invention can selectively transmit or reflect light having a specific wavelength over a wide range. Accordingly, the function of efficiently scattering light is excellent.
Moreover, if the manufacturing method of this invention is used, this multilayered structure non-spherical particle can be manufactured simply.

<Multilayer non-spherical particles>
The outer shape of the central layer (L0) is not limited as long as it constitutes the core, but is preferably non-spherical particles having an average circularity of 0.7 or more and less than 0.96, and more preferably an average circularity of 0. A non-spherical particle having an average circularity of 0.85 to 0.93 is particularly preferable.

  The average circularity is calculated by calculating a circumferential distance (r1) when the “maximum cross-sectional area” of the cross-sectional area of the particle is converted into a perfect circle, and this circular distance (r1) is calculated as “ A value obtained by dividing the “measured circumferential distance (r2)” is obtained for at least 1000 particles, and is an arithmetic average value of these values.

The “maximum cross-sectional area” is obtained by subjecting the sample dispersion to a narrow gap and irradiating light from a direction perpendicular to the flow direction, and image-processing the resulting shadow.
The “actually measured circumferential distance (r2)” is obtained by subdividing the image processing data obtained when obtaining the “maximum cross-sectional area” and counting the division points on the circumference.

  All the layers (Ln) are stacked concentrically with respect to the center of the core. The layer (Ln) is 2 or more layers, preferably 3 layers or more, more preferably 4 layers or more, particularly preferably 5 layers or more, from the viewpoint of selective transmission or reflection of light of a specific wavelength in a wide range. Most preferably, there are 6 or more layers. On the other hand, 30 layers or less are preferable from the viewpoint of production.

  N of the layer (Ln) corresponds to each layer and is an integer of 1 or more, and n of the layer adjacent to the central layer (L0) is 1, and n increases toward the outside. That is, the layer (L1) is laminated on the surface of the central layer (L0), the layer (L2) is laminated on the surface of the layer (L1), and the layers (L3), (L4),. The

  In all the layers of the central layer (L0) and the layer (Ln), all the refractive index differences (25 ° C.) of adjacent layers are 0.01 to 1.5, preferably 0.05 to 1.5. More preferably, it is 0.1 to 1.5, particularly preferably 0.2 to 1.5, next preferably 0.5 to 1.5, and most preferably 1 to 1.5. Within this range, selective transmission or reflection of light having a specific wavelength over a wide range is further improved. If it is less than the lower limit value, it will be difficult to sufficiently reflect or interfere with light, while if it exceeds the upper limit value, it will be difficult to obtain raw materials for producing multilayer structured particles.

The refractive index (25 ° C.) is obtained by forming a layer (Ln) having a film thickness v2 on a base film (thickness v1) having a refractive index of a1, obtaining a laminated film, and then calculating the refractive index (W) of the laminated film. Measure and obtain the refractive index (a2) of the layer (Ln) from the following equation.
a2 = [W− (a1 · v1 / (v1 + v2))] × [(v1 + v2) / v2]

  As for each thickness (micrometer) of a layer (Ln), 0.01-3 are preferable. From the viewpoint of selective reflection (diffusion) of light having a specific wavelength in a wide range, it is more preferably 0.1 to 3, particularly preferably 0.5 to 2.

The thickness (μm) of the center layer (L0) is preferably 0.05 to 3, and more preferably 0.1 to 2.5.
The thickness of the center layer (L0) means an average distance from the center of the core forming the center layer (L0) to the center layer surface.

  The thickness of the central layer (L0) and the layer (Ln) is determined by solidifying the multilayer non-spherical particles with a resin and cutting with a diamond cutter or the like, and observing the cross section of the multilayer non-spherical particles with a transmission electron microscope (TEM). ).

  The standard deviation of the thickness of at least one of the layers (Ln) is preferably 30% or less, more preferably 25% or less, from the viewpoint of light scattering.

The volume average particle diameter (μm) of the multilayer structure non-spherical particles of the present invention is preferably 0.1 to 20, more preferably 0.5 to 15, particularly preferably 1 to 10 from the viewpoint of light scattering. is there.
The volume average particle diameter can be measured by dispersing a measurement sample in water and using a light scattering type particle size distribution measuring instrument {for example, LA-950 manufactured by Horiba, Ltd.).

The volume (% by volume) of the central layer (L0) is preferably 5 to 98, more preferably 10 to 90, based on the volume of the multilayer non-spherical particles, from the viewpoint of light transmittance.
The volume of the central layer (L0) is measured by solidifying the multilayer non-spherical particles with a resin and cutting with a diamond cutter or the like, and measuring the cross section of the multilayer non-spherical particles using a transmission electron microscope (TEM). be able to.

As for the center layer (L0) and the layer (Ln), at least one of them may be a metal oxide layer (M), and all the layers may be metal oxide layers (M). M) and other layers {for example, the resin layer (R)} may be mixed.
When the other layer {for example, the resin layer (R)} and the metal oxide layer (M) are mixed, the other layer {for example, the resin layer (R)} and the metal oxide layer (M) It is preferable to have an alternately stacked structure.

  The center layer (L0) may be either a metal oxide layer (M) or another layer {for example, a resin layer (R)}, but a metal oxide layer (M) is preferable.

Examples of the metal oxide that can constitute the metal oxide layer (M) include silica, alumina, magnesium oxide, zinc oxide, titanium oxide, zirconium oxide, antimony oxide, and natural products containing these metal oxides. Can be mentioned. Examples of natural products include talc, kaolin clay, montmorillonite, mica, bentonite, rholite clay, and chrysotile.
Of these, at least one selected from the group consisting of silica, alumina, magnesium oxide, zinc oxide and titanium oxide is preferable from the viewpoint of ease of manufacture and refractive index, and more preferably a group consisting of silica, alumina and titanium oxide. It is at least 1 sort chosen from more.

  Other layers include a resin layer (R) and a metal nitride layer. Among these, the resin layer (R) is preferable from the viewpoint of ease of production.

  Resins that can constitute the resin layer (R) include those that are not colored and have film-forming properties, and from the viewpoint of transparency and refractive index, from the group consisting of polyurethane, polyester, vinyl resin, fluororesin, and polyamide. At least one selected is preferable, and more preferably at least one selected from the group consisting of vinyl resins, fluororesins and polyamides.

The resin layer (R) preferably contains a crosslinked resin.
Cross-linked resins include cross-linked vinyl resins copolymerized with monomers having two or more vinyl groups in one molecule, cross-linked urethane resins copolymerized with monomers or prepolymers having three or more isocyanate groups in one molecule, and glycidyl. Cross-linked epoxy resin copolymerized with a monomer or prepolymer having three or more groups, amino groups or carboxy groups in one molecule, amino group, carboxy group or anhydrous carboxy group {1,3-oxo-2-oxapropylene group} And a crosslinked polyamide obtained by copolymerizing a monomer or prepolymer having 3 or more per molecule.
When the crosslinked resin is included, the content (% by weight) of the crosslinked resin is preferably 30 to 100, more preferably 50 to 100, based on the weight of the resin layer (R).

  The multilayer structure non-spherical particles of the present invention are not limited in outer shape, but are preferably non-spherical particles having an average circularity of 0.7 or more and less than 0.96, and more preferably an average circularity of 0.80 to 0.00. 95 non-spherical particles, particularly preferably non-spherical particles having an average circularity of 0.85 to 0.93. The outer shape of the multilayer structured particle of the present invention greatly depends on the outer shape of the center layer (L0).

In a multilayer structure having a layer thickness of 0.01 to 0.2 μm, the light reflected by a certain layer interferes with the light reflected by the inner layer or the outer layer. The wavelength light corresponding to 1 appears colored (shows structural color). Various structural colors can be seen depending on the viewing angle. In addition, the greater the difference in refractive index between adjacent layers, and the greater the number of layers, the greater the reflection efficiency {the greater the amount of reflected light with respect to incident light}, and the stronger structural color is obtained. .

  On the other hand, in a multilayer structure having a layer thickness of 0.1 to 3 μm, no light interference occurs and reflection occurs in each layer. And as the number of layers increases, more efficient light scattering occurs. In addition, light diffusion occurs more efficiently with non-spherical particles than with spherical particles.

  Of the central layer (L0) and the layer (Ln), it is preferable that at least one layer contains the colorant (D). The colorant (D) is preferably at least one selected from the group consisting of dyes, pigments and phosphors from the viewpoints of the purity of color light and color reproducibility.

  As dyes, acid alizarin violet N, acid black, acid blue, acid chrome violet K, acid Fuchsin, acid green, acid orange, acid red, acid violet 6B, Direct yellow, Direct Orenge, Direct Violet, Direct Blue, Direct Green Mordant Yellow, Mordant Orange, Mordant Violet, Mordant Green, Food Yellow 3 and derivatives of these dyes. In addition, other dyes {azo-based, xanthene-based or phthalocyanine-based acidic dyes} can be used, such as CISolvent Blue 44,38, CISolvent Orenge 45, Rhodamine B, Rhodamine 110, 2,7-Naphthalenedisulfonic acid, and these Dye derivatives can also be used.

  As the pigment, a red colorant {C. I. Pigment red 254, C.I. I. Pigment Red 177, etc.}, green colorant {C.I. I. Pigment green 36, C.I. I. Pigment yellow 150 or C.I. I. Pigment Yellow 138 and the like} and blue colorant {C.I. I. Pigment blue 15, C.I. I. Pigment blue 22, C.I. I. Pigment blue 60 and C.I. I. Pigment blue 64 etc.}.

  Phosphors include inorganic phosphors {oxides such as rare earth elements (zinc, cadmium, magnesium, silicon, yttrium, etc.), sulfides, silicates, vanadates, etc.} and organic phosphors {fluorescein, eosin and oils. (Mineral oil) etc.}. The activator is selected from silver, copper, manganese, chromium, europium, zinc, aluminum, lead, phosphorus, arsenic, gold, and the like. The solvent is selected from sodium chloride, potassium chloride, magnesium carbonate, barium chloride and the like.

  When the colorant (D) is contained, the content (% by weight) of the colorant (D) is preferably 0.1 to 10, more preferably 0.5 to, based on the weight of the multilayer non-spherical particles. 5.

<Method for producing multilayer non-spherical particles>
When the center layer (L0) is a non-spherical resin layer, the center layer (L0) is produced by the following known method {of (1) to (5)} or the like.
(1) A method of adding a thickener {water-soluble polymer (polyvinyl alcohol, carboxymethylcellulose, polyvinylpyrrolidone, etc.)} to the continuous phase and performing a polymerization reaction under stirring in the emulsion polymerization method and suspension polymerization method, etc. .

(2) A method in which a thermoplastic resin is dispersed in a solvent, heated to a temperature higher than the glass transition temperature of the thermoplastic resin, and stirred and cooled under high shear.

(3) A method for producing resin particles by swelling them with a solvent and removing the solvent under a high share.

(4) A method in which a monomer is copolymerized with a cross-linking agent in an emulsion polymerization method, a suspension polymerization method, etc., and volume shrinkage due to a cross-linking reaction is used.

(5) A method of pulverizing and producing resin particles or metal oxide particles.

Among these, the method (1), (2) or (3) is preferable from the viewpoints of light scattering properties and surface smoothness.
When the center layer (L0) is a non-spherical metal layer, the center layer (L0) is manufactured by a method of applying the method (1) to the pulverization method and the sol-gel method.

  The multilayer non-spherical particles of the present invention can be produced by stacking two or more layers (Ln) concentrically with the non-spherical center layer (L0) as the core.

  As a method for producing a multilayered non-spherical particle by laminating two or more layers (Ln) concentrically with the center layer (L0) as a core, production steps (10), (20 ), (30) and at least two selected from the group consisting of (40), manufacturing method (1) including at least two types of repetition or one type of repetition; manufacturing method (2) including manufacturing step (50); And other manufacturing methods (3).

1. Manufacturing method (1)
1-1. Manufacturing process (10)
In the manufacturing process (10), a mass of resin or metal oxide forming the layer (L1) is placed in the dispersion liquid (D0) in which the central layer (L0) is dispersed, and a pulse laser is irradiated toward the mass. Then, fine particles are generated, and a resin layer (R1) or metal oxide layer (M1) is formed on the surface of the central layer (L0) to obtain a two-layer particle dispersion {after this, the two-layer particles are isolated It is preferable to do. }including.
Subsequently, the multilayer structure non-spherical particles can be obtained by combining the production steps (20), (30) and / or (40). On the other hand, a two-layered non-spherical particle dispersion {preferably a dispersion in which isolated two-layer particles are dispersed} (D1) can be obtained in the same manner as described above to obtain three-layer particles. Further, by repeating this operation, multi-layered non-spherical particles can be obtained. Moreover, the dispersion liquid (Dn) in which the multilayer particles obtained in the production steps (20), (30) and / or (40) are dispersed is prepared to obtain multilayer structure non-spherical particles in the same manner as described above. it can.

The center layer (L0) or multilayer particles are preferably dispersed uniformly in the solvent (E1).
Although it does not specifically limit as a dispersion method, The method using a well-known homogenizer, the method of disperse | distributing with an ultrasonic wave, etc. are preferable.
The solvent (E1) is not particularly limited as long as it does not absorb a pulse laser. For example, water and generally available organic solvents {acetone, methyl ethyl ketone, methanol, ethanol, toluene, xylene, hexane, dioxane, THF, DMF and DMSO etc. can be used.

  The content (% by weight) of the center layer (L0) or the multilayer particles is preferably 0.001 to 10, more preferably 0.005 to 5, based on the weight of the dispersion (D0) or the dispersion (Dn). It is.

The lump of resin or metal oxide is preferably placed on the bottom or side surface of the container containing the dispersion (D0) or dispersion (Dn).
The wavelength (nm) of the pulse laser is preferably 200 to 700, more preferably a wavelength that is not absorbed by the solvent.
The output (mJ / pulse) of the pulse laser is preferably 30 to 100.
The apparatus for oscillating the pulse laser is not particularly limited, but a YAG laser oscillating apparatus is preferable.

When irradiating with a pulse laser, the temperature (° C.) of the dispersion (D0) or the dispersion (Dn) is preferably 5 to 80.
The volume of the dispersion liquid (D0) or the dispersion liquid (Dn) is preferably 10 to 100 ml with respect to one pulse laser oscillation device.
The amount (volume%) of the resin or metal oxide lump is preferably 1 to 10 based on the volume of the dispersion (D0) or the dispersion (Dn).

Microparticles are generated from the mass irradiated with the pulse laser, and the microparticles adhere to the surface of the central layer (L0) or the multi-layered particles to form the resin layer (R) or the metal oxide layer (M). .
The multilayer particles on which the resin layer (R) or the metal oxide layer (M) is formed are isolated by centrifugation, vacuum filtration, pressure filtration, freeze drying, or the like.

1-2. Manufacturing process (20)
In the production step (20), the central layer (L0) having the reactive group (a) is reacted with the gaseous metal compound by heating to form a metal compound layer on the surface of the central layer (L0). After obtaining the metal compound layer particles, the unreacted gaseous metal compound is removed, and the metal compound layer particles and water vapor are reacted to change the metal compound layer into the metal oxide layer (M), thereby forming the two-layer particles. Including getting.
Subsequently, the multilayer structure non-spherical particles can be obtained by combining the production steps (10), (30) and / or (40). On the other hand, by reacting the two-layer particles with a gaseous metal compound, three-layer particles can be obtained in the same manner as in the above operation. Furthermore, multilayer structure particles can be obtained by repeating this operation. Moreover, multilayer structure non-spherical particles can be obtained in the same manner as described above by reacting the multilayer particles obtained in the production steps (10), (30) and / or (40) with a gaseous metal compound. In addition, when repeating the said operation, a gaseous metal compound may use the same kind as the first kind, and may use a different kind.

  The reactive group (a) is not limited as long as it can react with a gaseous metal compound, but a group having active hydrogen is preferable, and a hydroxyl group, a carboxy group, and an amino group are more preferable.

  The gaseous metal compound is not particularly limited as long as it reacts with the reactive group (a). Titanium halide {titanium chloride, etc.}, alkylaluminum {trimethylaluminum, etc.} and silicon halide {silicon chloride, etc.} Is preferred.

The reaction vessel is preferably a heat-resistant / pressure-resistant vessel, more preferably a heating device, a gas inlet and a decompression device, which are made of a material that does not react with a gaseous metal compound.
The water content in the reaction vessel is preferably small from the viewpoint of the stability of the metal compound, more preferably 100 ppm or less, and particularly preferably 10 ppm or less.
As reaction temperature (degreeC), 30-500 are preferable.

In order to remove the unreacted metal compound, a method of reducing the pressure inside the container, a method of replacing the inside of the container with an inert gas (such as nitrogen gas and helium gas), or the like can be applied.
The reaction temperature (° C.) between the metal compound layer and water vapor is preferably 30 to 500.

In the production process (20), a layer having a thickness of about 0.2 nm is formed once, and the production process (20) is repeated using the same kind of metal compound, whereby the target thickness can be obtained.
Therefore, when applying a manufacturing process (20), it is preferable to repeat the same manufacturing process (20) several times until it becomes predetermined thickness.

1-3. Manufacturing process (30)
The production step (30) includes at least one selected from the step (31); the step (32); the step (33); and the step (34).
That is, the manufacturing method including the manufacturing step (30) includes at least two types selected from the step (31); the step (32); the step (33); and the step (34), at least two types of repetition, or at least one type. Repeated or a combination of these and the manufacturing steps (10), (20) and / or (40) is included. In addition, when repeating a process (32) and / or a process (33), since the reactive surfactant which has the opposite ionicity is used alternately, after obtaining a multilayer particle dispersion, isolate | separate a multilayer particle { It is necessary to proceed to the next step after performing centrifugation, vacuum filtration, pressure filtration, freeze drying, etc.}. Further, when the step (31) and / or the step (34) is repeated, it is not always necessary to isolate the multilayer particles after obtaining the multilayer particle dispersion, but the multilayer particles are isolated {centrifugation, vacuum filtration, It is preferable to proceed to the next step after pressure filtration, freeze drying, and the like}.
The multilayer structure non-spherical particles to be subjected to the production method including the production step (30) are characterized in that at least one of the central layer (L0) and the layer (Ln) is a metal oxide layer (M). Is.

1-3-1. Step (31)
The active hydrogen includes a hydrogen atom contained in a hydroxyl group, a carboxy group, an amino group, or a mercapto group.

Examples of the alcohol having 1 to 4 carbon atoms include methanol, ethanol, isopropanol, propanol and butanol. Of these, ethanol, ethanol and isopropanol are preferred.
Examples of the aprotic solvent include ketones {acetone and methyl ethyl ketone and the like} and esters {ethyl acetate and butyl acetate and the like}. Of these, methyl ethyl ketone, ethyl acetate and butyl acetate are preferred.

  The concentration (volume%) of the central layer (L0) or multilayer particles is preferably 0.01 to 10, more preferably 0.02 to 8, based on the volume of the dispersion (D0) or the dispersion (Dn). is there. Within this range, the standard deviation of the layer thickness is further improved.

The center layer (L0) or multilayer particles are preferably dispersed uniformly in the alcohol or the aprotic solvent (E31).
Although it does not specifically limit as a dispersion method, The method using a well-known homogenizer, the method of disperse | distributing with an ultrasonic wave, etc. are preferable.

  As the metal alkoxide, alkali metal {lithium, sodium, potassium, etc.}, alkaline earth metal {magnesium, calcium, etc.}, heavy metal {titanium, zirconium, iron, copper, etc.}, aluminum or silicon alkoxide {C 1-4 Methoxide, ethoxide, propoxide, isopropoxide, n-butoxide, etc.} and the like. Of these, alkoxides of heavy metals, aluminum or silicon are preferred.

As the sol-gel method, a known method {for example, a method in which a small amount of hydrochloric acid is added to the dispersion liquid (D0) or the dispersion liquid (Dn) and then a metal alkoxide is added to react) can be applied.
As reaction temperature (degreeC), 5-150 are preferable, More preferably, it is 10-80.
It is preferable to use a catalyst for the reaction.
As the catalyst, metal catalyst {tin catalyst (dibutyltin dilaurate, stannous octoate, stannous chloride, tetrabutyl zirconate, etc.), lead catalyst (lead oleate, lead naphthenate, lead octenoate, etc.)}, Amine catalysts {triethylenediamine and dimethylethanolamine etc.}, acid catalysts {boron trifluoride, hydrochloric acid, paratoluenesulfonic acid and dodecylbenzenesulfonic acid etc.}, base catalysts {amines and alkaline earth metal hydroxides etc.} and salts {Quaternary onium salt etc.} and the like.

  Active hydrogen exists in the metal oxide layer formed in the step (31). Therefore, following the step (31), the step (31) or the step (34) can be applied.

1-3-2. Process (32)
The reactive surfactant (S1) is not particularly limited as long as it has a group copolymerizable with the resin precursor (m) and is a cationic or anionic surfactant.
Examples of the group copolymerized with the precursor (m) include vinyl group, isocyanato group, blocked isocyanato group, glycidyl group, amino group, hydroxyl group and carboxy group.

  As an anionic reactive surfactant, a sodium salt of an alkyl (carbon number 12 to 13) allyl diester of sulfosuccinic acid {for example, Eleminol JS-2: manufactured by Sanyo Chemical Industries Ltd. ("Eleminol" is a registered trademark of the company) }}, Sodium sulfonate ester salt of polyoxyalkylene methacrylate {for example, Eleminol RS-30: manufactured by Sanyo Chemical Industries Ltd.}, and ammonium sulfate ester salt of allyloxymethyl polyoxyethylene hydroxyalkyl ether {AQUALON KH-10 : Daiichi Kogyo Seiyaku Co., Ltd. (“AQUALON” is a registered trademark of the company)} and the like.

  Cationic reactive surfactants include compounds having a methacryloxy group and a trialkylammonio group in the same molecule {methacryloxyethylaminocarbonyloxyethyltrimethylammonium methosulfate salt}, and trimethylammonioethyl chloride methacrylate Preferred examples include salts (reference: 13th Polymer Microsphere Discussion 2B10 Seiko Epson).

  The amount (% by weight) of the reactive surfactant (S1) used is preferably from 1 to 100, more preferably from 1.5 to 80, based on the weight of the resin precursor (m). Within this range, the standard deviation of the layer thickness is further improved.

The surface of the multilayer particle or the central layer (L0) preferably has a charge (q), more preferably a ζ (zeta) potential of 0.1 mV or more, or a ζ (zeta) potential of −0.1 mV or less. Is to have.
And it is preferable that the ionicity of this electric charge (q) and reactive surfactant (S1) is opposite. For example, when the charge (q) is negative, the reactive surfactant is preferably cationic. On the other hand, for example, when the charge (q) is positive, the reactive surfactant is preferably anionic.

The multilayer particle or the central layer (L0) having a charge (q) preferably has an ionic group on the surface. Examples of the ionic group include an anion group {carboxylate group (—CO ₂ ⁻ ), phosphonate group (—PO (O ⁻ ) ₂ or —PO (OH) (O ⁻ )), and sulfonate group (—SO ₃ ⁻ ) group. Etc.}, and cationic groups {ammonio group (—NH ₃ ⁺ ), quaternary ammonio group (—NR ₃ ⁺ ; R is a hydrocarbon group having 1 to 3 carbon atoms), sulfonio group (—SH ₂ ⁺ ), and phosphonio group (-PH ₃ ⁺ ) and the like}.

  In the dispersion liquid containing the reactive surfactant (S1) and the multilayer particles or the central layer (L0), water, alcohol having 4 or less carbon atoms, or the like is used as a dispersion solvent.

The center layer (L0) or multilayer particles are preferably dispersed uniformly in the dispersion solvent.
Although it does not specifically limit as a dispersion method, The method using a well-known homogenizer, the method of disperse | distributing with an ultrasonic wave, etc. are preferable.
The content (volume%) of the central layer (L0) or the multilayer particles in the dispersion is preferably 0.01 to 50 based on the volume of the dispersion.

The reactive surfactant (S2) is particularly limited as long as it has a group copolymerizable with the resin precursor (m) and has an ionicity opposite to that of the reactive surfactant (S1). Not.
If the reactive surfactant (S1) is anionic, the reactive surfactant (S2) is cationic, while if the reactive surfactant (S1) is cationic, the reactive surfactant ( S2) is anionic.

Examples of the group copolymerized with the precursor (m) include vinyl group, isocyanato group, blocked isocyanato group, glycidyl group, amino group, hydroxyl group and carboxy group.
As reactive surfactant (S2), the same thing as reactive surfactant (S1) is contained.

  The use weight ratio {(S1) / (S2)} of the reactive surfactant (S1) and the reactive surfactant (S2) is preferably 1/2 to 2/1.

  The precursor (m) of the resin may be any precursor as long as it reacts to become a resin, and includes a vinyl monomer, a glycidyl group-containing compound, and the like.

  Since the usage-amount (volume%) of the precursor (m) of resin is directly related to the film thickness of a resin layer, 0.1-100 are preferable based on the volume of a multilayer particle, or the volume of a center layer (L0). . Within this range, the standard deviation of the layer thickness is further improved.

As a method of copolymerizing the reactive surfactant (S1), the reactive surfactant (S2), and the resin precursor (m), a known method can be applied, but heat, ultraviolet irradiation (UV) or electron beam can be applied. A method using irradiation (EB) is preferable, and a method using heat is more preferable.
In the case of heat, the reaction temperature (° C.) is preferably 30 to 160.

  In the step (32), a double micelle layer is formed on the surface of the multilayer particle or the central layer (L0), and the precursor (m) is trapped therein, and the reactive surfactant (S1), the reactive surfactant A resin layer is formed by copolymerizing (S2) and the precursor (m).

1-3-3. Step (33)
In the step (33), “a multilayer layer having a metal oxide layer on the surface or a central layer composed of a metal oxide (L0)” is replaced with “a multilayer layer having a resin layer on the surface or a central layer composed of a resin”. The process is the same as the process (32) except for changing to (L0) ".

1-3-4. Process (34)
In the step (34), “the central layer (L0) composed of a resin having active hydrogen (L0)” or “multilayer particles whose surface is composed of a resin layer having active hydrogen” is converted from “a metal oxide having active hydrogen”. It is the same as the step (31) except that it is changed to “constituted central layer (L0)” or “multilayer particles whose surface is composed of a metal oxide layer having active hydrogen”.

1-4. Manufacturing process (40)
In the step (40), after the step (31) or the step (34), the multilayer structure non-spherical particles are preferably obtained by isolating the multilayer particles.
Subsequently, the multilayer structure non-spherical particles can be obtained by combining the production steps (10), (20) and / or (30). In addition, multilayer non-spherical particles can be obtained in the same manner as described above using the multilayer particles obtained in the production steps (10), (20) and / or (30). In addition, when repeating the said operation, a metal alkoxide may use the same kind as the first kind, and may use a different kind.

2. Manufacturing method (2)
2-1. Manufacturing process (50)
The central layer (L0) made of a resin or metal oxide and having a charge (q) on the surface is an ionic group on the surface (the same as the ionic group in step (32)). } Is preferable.

  The charge (q) is preferably a ζ (zeta) potential of 0.1 mV or more or a ζ (zeta) potential of −0.1 mV or less.

  As a dispersion solvent for the dispersion, water, alcohol having 4 or less carbon atoms, and the like are used.

The center layer (L0) or multilayer particles are preferably dispersed uniformly in the dispersion solvent.
Although it does not specifically limit as a dispersion method, The method using a well-known homogenizer, the method of disperse | distributing with an ultrasonic wave, etc. are preferable.
The content (volume%) of the central layer (L0) or multilayer particles in the dispersion is preferably from 0.01 to 50, more preferably from 0.02 to 40, based on the volume of the dispersion.

The resin particles (P0) are not particularly limited as long as they have a charge (r) opposite to the charge (q) and the particle size is one tenth of the particle size of the central layer (L0) or the multilayer particle.
The resin particles (P0) are obtained by general emulsion polymerization, suspension polymerization, miniemulsion method or dispersion polymerization. Of these, emulsion polymerization is preferred from the viewpoint of particle size control.
As for the volume average particle diameter (micrometer) of a center layer (L0) or a multilayer particle, 0.1-20 are preferable.
The volume average particle diameter (μm) of the resin particles (P0) is preferably from 0.01 to 2, and more preferably from 0.02 to 1.

The content (volume%) of the center layer (L0) or multilayer particles is preferably 0.01 to 50 based on the volume of the dispersion.
The content (% by weight) of the resin particles (P0) is preferably 0.1 to 100, more preferably 5 to 100, based on the weight of the central layer (L0) or the multilayer particles.

  The multilayer particles forming the resin layer are preferably isolated by centrifugation, vacuum filtration, pressure filtration or freeze-drying, and the same operation is repeated using this dispersion (preferably isolated multilayer particles). Thus, multi-layered non-spherical particles are produced.

3. Other manufacturing methods (3)
If the multilayer non-spherical particles of the present invention have a central layer (L0) as a core and two or more layers (Ln) can be laminated concentrically with the center of the core, in addition to the above production method, It can also be produced by a known method.
3-1. Manufacturing process (60)
A production method for obtaining multilayered non-spherical particles by dissolving block polymers having different solubility parameters in an organic solvent, dispersing the solution in water using a surfactant, and removing the solvent.
3-2. Manufacturing process (70)
By using a coupling agent or the like to the reactive group on the surface of the central layer (L0) or the multilayer particle, a vinyl group is introduced, and a vinyl monomer is grafted. Manufacturing method to obtain.
3-3. Manufacturing process (80)
A production method in which a multilayered non-spherical particle is obtained by forming a small particle layer on the surface of a large particle by causing the large particle and the small particle to collide at high speed in a dry process, and repeating this operation.
3-4. Manufacturing process (90)
By dispersing large particles and small particles in a solvent and stirring the solution at a high speed, a layer of small particles is formed on the surface of the large particles, and this operation is repeated to obtain multilayered non-spherical particles. Production method.

Among these manufacturing methods, it is preferable to include manufacturing steps (10) to (50).
In addition, you may combine manufacturing process (10)-(90).
Examples of combinations include steps (10) and (30), steps (20) and (30), steps (30) and (50), and the like. Among these, from the viewpoint of controllability of the refractive index difference, the steps (10) and (30) and the steps (20) and (30) are preferable.

  The multilayer structure non-spherical particles of the present invention can be applied to resin films, coating materials {matte paints, reflectors / reflective film paints, etc.}, light diffusion films and the like.

  The multilayer structure non-spherical particle of the present invention is particularly suitable for a light diffusion film. It is also suitable for resin films and coating materials.

The light diffusing film and the resin film are (1) a method of melt-kneading a resin for film and multilayer structure particles, and extrusion-extrusion molding. And (3) a method in which the multilayer structure particles are dispersed in a monomer and then polymerized.
The content (% by weight) of the multilayer structure non-spherical particles is preferably 1 to 80, more preferably 5 to 50, based on the total weight of the resin for film and the multilayer structure non-spherical particles.
Examples of the resin for film include optical resins {for example, polymethyl methacrylate (PMMA), polycarbonate and polyester}, and binder resins {for example, urethane resin, epoxy resin, acrylic resin and polyester}).

  The coating material is obtained by mixing raw materials used in known paints and inks {binders and solvents, etc.} and the multilayered non-spherical particles of the present invention {the multilayered non-spherical particles are subjected to shear stress due to mixing. Care must be taken not to destroy it. }.

The present invention will be further described with reference to examples, but the present invention is not limited thereto.
Hereinafter, parts indicate parts by weight and% indicates% by weight.

<Production Example 1>: Production of titania non-spherical particles (center layer) 200 parts of titanium tetraisopropoxide, 750 parts of methyl ethyl ketone, 20 parts of polyvinyl pyrrolidone (number average molecular weight 40000) were uniformly mixed, and then heated to 50 ° C. 2 parts of a 1% aqueous ammonia solution was added dropwise over 30 minutes. After dripping, it heated to 80 degreeC and made it react for 8 hours, and obtained the dispersion liquid containing a non-spherical titania particle (LB-1). Non-spherical titania particles (LB-1) were obtained by centrifuging the dispersion, washing with water, and drying (volume average particle size 2.7 μm, average circularity 0.91).

<Production Example 2>
950 parts of ion exchange water, 45 parts of non-spherical titania particles (LB-1) and sodium dodecylbenzenesulfonate were mixed and irradiated with ultrasonic waves for 30 minutes to obtain a dispersion. This dispersion is filled into a chamber of a submerged laser ablation system [manufactured by Nara Machinery Co., Ltd.], a polytetrafluoroethylene lump is set, and the laser is irradiated for 3 hours to obtain non-spherical titania particles (LB-1). Polytetrafluoroethylene was vapor-deposited on the surface to obtain a dispersion containing two-layer structure non-spherical particles (LB-2). The two-layer structure non-spherical particles (LB-2) were obtained by centrifuging the dispersion, washing with water, and then drying {volume average particle diameter 3.2 μm, average circularity 0.91}.

<Example 1>
Production Example 2 except that “non-spherical titania particles (LB-1)” were changed to “two-layer non-spherical particles (LB-2)” and “polytetrafluoroethylene” was changed to “titania”. In the same manner as above, a three-layered non-spherical particle (LB-3) having a titania layer-polytetrafluoroethylene layer-titania layer was obtained {volume average particle size 4.0 μm, average circularity 0.92}.

<Example 2>
Titania layer-polytetrafluoroethylene layer-titania layer in the same manner as in Production Example 2, except that "Non-spherical titania particles (LB-1)" was changed to "Three-layer structure non-spherical particles (LB-3)" -Four-layer structure non-spherical particles (LB-4) having a polytetrafluoroethylene layer were obtained {volume average particle size 4.7 μm, average circularity 0.93}.

<Production Example 3>
Production of cationic surfactant containing reactive surfactant: In a pressure-resistant container having a stirring device, 100 parts of 2- (methacryloyloxy) ethyl isocyanate [Karenz MOI: Showa Denko Co., Ltd.], 57 parts of dimethylaminoethanol, dibutyltin 1 part of dilaurate was added and reacted at 80 ° C. for 8 hours. To this solution, 81 parts of dimethyl sulfate was further added and reacted at 60 ° C. for 4 hours to obtain a cationic group-containing reactive surfactant (S-1).

<Production Example 4>
Production of resin particles: 720 parts of ion-exchanged water, 80 parts of carboxymethyl cellulose [SG Serogen BS-H: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.], 5 parts of sodium dodecylbenzenesulfonate in a glass container, homogenized, and the aqueous phase Obtained. In another container, add 100 parts of styrene, 60 parts of divinylbenzene, 20 parts of hydroxyethyl methacrylate, 5 parts of azobisbutyronitrile, 15 parts of an anionic reactive surfactant [Eleminol JS-2: Sanyo Chemical Industries, Ltd.] An oil layer was obtained by homogenization. The whole oil layer was added to the aqueous phase, and the mixture was stirred for 1 minute at 3000 rpm using a rotor-stator type disperser [TK Homomixer: made by Tokushu Kika Kogyo Co., Ltd.], then transferred to a pressure vessel having a stirrer, 85 ° C., 12 The mixture was reacted for a time to obtain a non-spherical resin particle dispersion. The obtained dispersion liquid was taken out using a centrifuge, washed with water, and dried to give non-spherical resin particles (LB-) made of crosslinked polystyrene having an anionic charge on the surface and active hydrogen on the surface. 5) was obtained. The volume average particle diameter was 6.2 μm, and the average circularity was 0.91.

<Production Example 5>
Production of multilayered non-spherical particles: 750 parts of methyl ethyl ketone, 7 parts of polyvinyl pyrrolidone (number average molecular weight 40000) as protective colloid and 50 parts of (LB-5) are added to a pressure vessel having a stirrer, and uniformly dispersed, then 50 ° C. And 2 parts of a 1% aqueous ammonia solution was added dropwise using a dropping funnel over 1 hour. After dropping, 2.82 parts of tetraethoxysilane was added dropwise over 1 hour using a dropping funnel, heated to 80 ° C., and reacted for 8 hours to obtain a dispersion. A part of the obtained dispersion was taken out using a centrifuge, washed with water, and then dried to obtain two-layered non-spherical particles (LB-6). The central layer (L0) is crosslinked polystyrene, and the layer (L1) is silica. The volume average particle diameter was 6.5 μm, and the average circularity was 0.91.

<Example 3>
In a pressure vessel having a stirrer, 800 parts of ion-exchanged water, 0.2 part of (S-1), 50 parts of two-layered non-spherical particles (LB-6) were added and uniformly dispersed. In a separate container, 1.2 parts of styrene, 1.0 part of divinylbenzene, 0.6 part of hydroxyethyl methacrylate, 0.18 part of azobisbutyronitrile, an anionic reactive surfactant [Eleminol JS-2: Sanyo Chemical Made by Kogyo Co., Ltd.] 0.2 parts was added to homogenize to obtain an oil layer. The previous dispersion was heated to 85 ° C., and the oil layer was added dropwise with stirring over 1 hour using a dropping funnel. The mixture was reacted for 12 hours to obtain a non-spherical resin particle dispersion. The obtained dispersion was taken out using a centrifuge, washed with water, and dried to obtain a three-layer non-spherical particle (LB-7) having a layer structure of crosslinked polystyrene-silica-crosslinked polystyrene. It was. The volume average particle diameter was 6.8 μm, and the average circularity was 0.92.

<Example 4>
(LB-5) was changed to (LB-6), and the same treatment as in Production Example 4 was performed to obtain a four-layered non-spherical particle (LB-8) having a cross-linked polystyrene-silica alternating layered structure. . The volume average particle diameter was 7.1 μm, and the average circularity was 0.92.

  Table 1 summarizes the number of layers (n), the volume average particle diameter, the average circularity, and the refractive index of each layer for the multilayer structured particles obtained in Examples 1 to 4.

Note) The average thickness and standard deviation were the same for all the polytetrafluoroethylene layers.
2. The average thickness and standard deviation were the same for all titania layers.
3. The average thickness and standard deviation were the same for all crosslinked polystyrene layers.
4). The average thickness and standard deviation were the same for all silica layers.
5. Average layer thickness; average value of all layers.

The volume average particle diameter, average circularity, average layer thickness, number of layers (n) and refractive index were measured by the following methods.
(1) Evaluation of volume average particle diameter and average circularity 1 part of multilayer structure spherical particles, 1 part of sodium dodecylbenzenesulfonate and 98 parts of ion-exchanged water were mixed, and an ultrasonic wave was irradiated for 30 minutes to prepare a dispersion. . The volume average particle diameter and average circularity of this dispersion were measured with a flow type particle image analyzer [manufactured by Sysmex Corporation: FPIA-3000].

(2) Measurement of Average Layer Thickness and Number of Layers (n) Multilayer structured spherical particles are made of epoxy resin {Epicoat 828, Japan Epoxy Resin Co., Ltd., "Epicoat" is a registered trademark of Resolution Research Netherland is there. }, And the cured product was cut with a microcutter, the cross section was observed with a transmission electron microscope (TEM), the thickness of 10 points per layer was measured, and the average value was calculated.
The number of layers (n) was confirmed by observing the cross section.

(3) Measurement of Refractive Index of Each Layer In the case of a resin layer, a measurement sample was prepared by applying a resin solution with an applicator. On the other hand, in the case of the metal oxide layer, a measurement sample was prepared by a sol-gel method.
The refractive index was measured at 25 ° C. using an Abbe refractometer [manufactured by Atago Co., Ltd .: NAR-4T].

  The multilayer structure non-spherical particles obtained in Examples 1 to 4 were evaluated for the total light transmittance and haze by the following methods. The results are shown in Table 2. The non-spherical particles obtained in Production Examples 1 and 4 were evaluated in the same manner and shown in Table 2.

<Total light transmittance and haze>
189 parts of methyl methacrylate, 1 part of photopolymerization initiator [IRGNOX1010: manufactured by Ciba Specialty Chemicals Co., Ltd.], 10 parts of an evaluation sample {multilayered structure non-spherical particles or non-spherical particles} are mixed and irradiated with ultrasonic waves for 5 minutes. To obtain a dispersion. This dispersion was applied on a 50 mm × 50 mm glass substrate with an applicator so that the liquid film thickness was 200 μm, and a resin film (A) was formed by irradiating ultraviolet rays from an ultraviolet lamp for 10 seconds.

  Resin film (B) was formed in the same manner as above except that methyl methacrylate was changed from “189 parts” to “169 parts” and the evaluation sample was changed from “10 parts” to “30 parts”. did.

Using a haze meter NDH2000 (Nippon Denshoku Co., Ltd.), the total light transmittance and haze of the resin film (A) or (B) {including the glass substrate} were measured.
In addition, it shows that the light diffusibility is so high that haze is high, and the loss of light is so small that total light transmittance is high.

  The resin films using the multilayered non-spherical particles obtained in Examples 1 to 4 were excellent in both haze and total light transmittance that were originally in a reciprocal relationship. On the other hand, the non-spherical particles obtained in Production Examples 1 and 4 were inferior in both haze and total light transmittance.

  The multilayered non-spherical particles of the present invention are extremely useful as a light diffusing film, a light diffusing plate, a light guide plate or an antiglare film for display.

Claims (18)

The center layer (L0) is a core, and a structure in which two or more layers (Ln) are stacked concentrically with the center of the core. The refractive index difference (25 ° C.) of adjacent layers is all 0. A multilayered non-spherical particle having a particle diameter of 01 to 1.5, wherein at least one of the central layer (L0) and the layer (Ln) is a metal oxide layer (M). 2. The multilayered non-spherical particle according to claim 1, wherein an average thickness of at least one of the layers (Ln) is 0.01 to 3 μm. 3. The multilayered non-spherical particle according to claim 1, wherein the standard deviation of the thickness of at least one of the layers (Ln) is 30% or less. The multilayer structure non-spherical particle according to any one of claims 1 to 3, wherein the volume average particle diameter is 0.1 to 20 µm. The multilayer non-spherical particle according to any one of claims 1 to 4, wherein the volume of the central layer (L0) is 5 to 98% by volume based on the volume of the multilayer non-spherical particle. The multilayer according to any one of claims 1 to 5, wherein at least one of the center layer (L0) and the layer (Ln) is a resin layer (R), and at least one layer is a metal oxide layer (M). Structure non-spherical particles. The multilayer non-spherical particle according to claim 6, wherein the resin layer (R) contains a crosslinked resin. The multilayered non-spherical particle according to claim 6 or 7, having a structure in which a resin layer (R) and a metal oxide layer (M) are alternately laminated. The multilayered non-spherical particle according to any one of claims 6 to 8, wherein the resin layer (R) is at least one selected from the group consisting of polyurethane, polyester, vinyl resin, fluororesin, and polyamide. The multilayered non-spherical particle according to any one of claims 1 to 9, wherein the metal oxide layer (M) is at least one selected from the group consisting of silica, alumina, magnesium oxide, zinc oxide and titanium oxide. . The multilayer non-spherical particle according to any one of claims 1 to 10, wherein the central layer (L0) is a metal oxide layer (M). The multilayer structure according to any one of claims 1 to 11, wherein at least one of the central layer (L0) and the layer (Ln) contains at least one selected from the group consisting of dyes, pigments, and phosphors. Non-spherical particles. The multilayered non-spherical particle according to any one of claims 1 to 12, which is a non-spherical particle having an average circularity of 0.7 or more and less than 0.96. A resin film containing the multilayered non-spherical particles according to claim 13. A coating material containing the multilayered non-spherical particles according to claim 13. A light diffusion film using the multilayer non-spherical particles according to claim 13. A central layer (L0) comprising at least two types selected from the group consisting of the manufacturing steps (10), (20), (30) and (40), at least two types of repetition or at least one type of repetition. ) And at least one of the layers (Ln) is a metal oxide layer (M).
In the dispersion liquid (D0) in which the central layer (L0) is dispersed or in the dispersion liquid (Dn) in which the multilayer particles are dispersed, a lump of resin or metal oxide is placed, and this lump is irradiated with a pulse laser to form fine particles. A production step of obtaining a multilayer structure non-spherical particle by forming a resin layer (R) or a metal oxide layer (M) on the surface of the central layer (L0) or the multilayer particle to obtain a multilayer particle dispersion. 10);
The central layer (L0) or multilayer particle having a reactive group (a) or multilayer particle having a reactive group (a) on the surface and a gaseous metal compound are reacted by heating. After forming a metal compound layer on the surface of the metal to obtain metal compound layer particles, unreacted gaseous metal compound is removed, and the metal compound layer particles and water vapor are reacted to form the metal compound layer as a metal oxide layer (M A production step (20) for obtaining multilayer non-spherical particles by obtaining multilayer particles by changing to
The surface of the dispersion layer (D0) in which the central layer (L0) composed of a resin having active hydrogen is dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31) or a resin layer having active hydrogen A metal alkoxide is added to a dispersion (Dn) in which multi-layered particles are dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31), and a central layer (L0) is obtained by a sol-gel method. Or a step of forming a metal oxide layer on the surface of the multilayer particles to obtain a multilayer particle dispersion (31);
A central layer (L0) composed of a cationic or anionic reactive surfactant (S1) copolymerizable with the resin precursor (m) and multilayer particles or metal oxide having a metal oxide layer on the surface In a dispersion containing
After adding a reactive surfactant (S2) copolymerizable with the resin precursor (m) and having an ionicity opposite to that of the reactive surfactant (S1), and the resin precursor (m) ,
The reactive surfactant (S1), the reactive surfactant (S2), and the resin precursor (m) are copolymerized to form a resin layer on the surface of the multilayer particle or the central layer (L0). Isolating multilayer particles after obtaining the liquid (32);
Contains a cationic or anionic reactive surfactant (S1) copolymerizable with the resin precursor (m) and a multilayer layer having a resin layer on the surface or a central layer (L0) composed of a resin Into the dispersion
After adding a reactive surfactant (S2) copolymerizable with the resin precursor (m) and having an ionicity opposite to that of the reactive surfactant (S1), and the resin precursor (m) ,
The reactive surfactant (S1), the reactive surfactant (S2), and the resin precursor (m) are copolymerized to form a resin layer on the surface of the multilayer particle or the central layer (L0). After obtaining the liquid, the step (33) of isolating the multilayer particles; and the central layer (L0) composed of the metal oxide having active hydrogen is used as the alcohol having 1 to 4 carbon atoms or the aprotic solvent (E31). ) Dispersed in the dispersion liquid (D0) or the multilayer particles whose surface is composed of a metal oxide layer having active hydrogen in alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31) Step (34) of adding a metal alkoxide to the dispersion (Dn) and forming a metal oxide layer on the surface of the central layer (L0) or the multilayer particles by a sol-gel method to obtain a multilayer particle dispersion
A production step (30) for obtaining multi-layered non-spherical particles by containing at least one selected from:
It has a dispersion (D0) or active hydrogen in which a central layer (L0) composed of a resin or metal oxide having active hydrogen is dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31). A metal alkoxide is added to a dispersion liquid (Dn) in which multilayer particles whose surface is composed of a resin layer or a metal oxide layer are dispersed in an alcohol having 1 to 4 carbon atoms or an aprotic solvent (E31). The production process (40) of obtaining a multilayer structure non-spherical particle by forming a metal oxide layer on the surface of the central layer (L0) or multilayer particle by a sol-gel method to obtain a multilayer particle dispersion liquid In the dispersion liquid (D0) in which the central layer (L0) having the charge (q) is dispersed on the surface or the dispersion liquid (Dn) in which the multilayer particles having the charge (q) are dispersed on the surface, the particle size of the central layer ( L0) or the surface of the central layer (L0) or multilayer particle by adding particles (P0) having a charge (r) opposite to the charge (q) and not more than one-tenth of the particle diameter of the multilayer particle After forming a layer composed of particles (P0) to obtain a multilayer particle dispersion,
A multilayer in which at least one of the central layer (L0) and the layer (Ln) is a metal oxide layer (M), which includes a production step (50) for obtaining multi-layered non-spherical particles by repeating the above operation Method for producing structured non-spherical particles.