JP2022145981A - Nonspherical hollow particle, dispersion containing the same and its use - Google Patents

Abstract

To provide a rutile-type titanium oxide hollow particles excellent in sedimentation stability and particle strength, when used for example as a pulverized cosmetic, excellent in brightness and glossiness, and when contained as a colorant, a white ink excellent in hiding property can be obtained.SOLUTION: Non-spherical hollow particles contain (A) titanium oxide, having a major axis diameter to minor axis diameter ratio of 1.1 to 10.0, and preferably a major axis diameter coefficient of variation (CV) of 0.1 to 10%; and (B) silica.SELECTED DRAWING: Figure 2

Description

TECHNICAL FIELD The present invention relates to non-spherical hollow particles, dispersions containing the same, and uses thereof.

Hollow particles are particles that have voids inside. Conventionally, hollow particles have been widely used as microcapsules in which various functional substances are encapsulated in the pores. In addition, since hollow particles have light scattering properties due to the pores, they are used in coating agents for paper, fibers, leather, glass, metals, etc., inks, paints, cosmetics, etc. It is useful as a light scattering agent or a light scattering aid that imparts performance such as whiteness. Furthermore, hollow particles are also expected to be used as a refractive index adjuster, a lightening agent, a sound insulating material, a heat insulating material, and the like. For example, Patent Documents 1 and 2 disclose hollow particles containing silica or alumina.

Among hollow particles, hollow particles containing metal oxides such as silica, titanium oxide, and zirconium oxide are industrially useful due to their excellent structural stability and chemical stability, and are used as weight-reducing materials and white pigments. It is expected to be applied as In particular, hollow particles containing titanium oxide are considered useful as light scattering materials and catalyst materials because of their high refractive index and catalytic activity. Methods for producing hollow titanium oxide are disclosed in Patent Documents 3 and 4, for example.

Further, Patent Document 3 discloses a method for producing a particle-encapsulated metal oxide hollow granule in which a shell is formed of titanium oxide. However, since particles are present inside the produced hollow granules, there is a concern that the density will be high and the settling property will be poor.

Patent Literature 4 discloses hollow particles in which agglomerates of rutile-type titanium oxide particles form shells. However, the shell is a collection of nanoparticles of rutile-type titanium oxide and has pores.

Non-Patent Document 1 discloses hollow particles using anatase-type titanium oxide. However, since the anatase type has a photocatalytic function, there is a concern that when combined, the compound such as resin may be decomposed by light.

JP 2013-43788 A JP 2010-120786 A International Publication 2018/207751 International publication 2019/117075

SONG, X et al. , Fabrication of Hollow Hybrid Microspheres Coated with Silica/Titania via Sol-Gel Process and Enhanced Photocatalytic Activities, J. Am. Phys. Chem. C, 2007.05.16, Vol. 111, p. 8180-, ISSN 1932-7447

As described above, hollow particles containing silica or metal oxides are expected to be applied as white pigments and the like. However, the present inventors confirmed that conventional hollow particles have room for improvement in sedimentation stability and particle strength.
When hollow particles with poor sedimentation stability are used, for example, as a white pigment to prepare a white ink, the dispersed state is easily broken, and the pigment tends to sediment. For this reason, before using the white ink, it is necessary to return the precipitated pigment to a uniformly dispersed state by an operation such as stirring, resulting in poor operability.
In addition, if the particle strength of the hollow particles is low, the hollow particles will be broken during the preparation of the dispersion, making it impossible to maintain the hollow state. Therefore, it becomes difficult to obtain good dispersion stability due to the hollow particles. In addition, if the hollow particles are broken during preparation of the dispersion, particles of various sizes are generated in the dispersion, making it difficult to prepare a dispersion having a narrow particle size distribution and a uniform primary particle size. . As a result, it becomes difficult to obtain a white ink with good opacity.
Accordingly, an object of the present invention is to provide hollow particles that are excellent in sedimentation stability and particle strength and have good hiding properties, dispersions containing the hollow particles, and uses thereof.

As a result of intensive studies, the present inventors have found that hollow particles containing titanium oxide and having a specific aspect ratio can solve the above problems, and have completed the present invention. In order to improve the particle strength, it is conceivable to unilaterally increase the thickness of the outer shell. It was also found by the inventors that hollow particles cannot be formed.
That is, the present invention relates to the following 1) to 11).
1)
(A) contains titanium oxide,
Non-spherical hollow particles having a major axis diameter to minor axis diameter ratio of 1.1 to 10.0.
2)
The non-spherical hollow particles according to 1) above, wherein the coefficient of variation (CV) of the major axis diameter is 0.1 to 10%.
3)
The non-spherical hollow particles according to 1) or 2) above, which have a major axis diameter of 10 nm to 1000 nm.
4)
The non-spherical hollow particles according to any one of 1) to 3), further comprising (B) silica.
5)
The non-spherical hollow particles according to any one of 1) to 4) above, wherein (A) contains (A-1) rutile-type titanium oxide.
6)
4) wherein the content of (A) titanium oxide is 86.0% by mass to 99.5% by mass or less and the content of (B) silica is 0.5% by mass to 14.0% by mass; or The non-spherical hollow particles according to 5).
7)
Any one of the above 1) to 6), wherein E/F is 0.3 to 0.95, where E is the major axis diameter of the hollow particles and F is the major axis of the non-spherical hollow particles. The non-spherical hollow particles according to Item 1.
8)
A cosmetic using the non-spherical hollow particles according to any one of 1) to 7) above.
9)
(I) A dispersion containing the non-spherical hollow particles according to any one of 1) to 7) above and (II) a solvent.
10)
The dispersion according to 9) above, which further contains (III) a dispersant.
11)
A white ink using the dispersion described in 9) or 10) above.

According to the present invention, it is possible to obtain a white ink which is excellent in sedimentation stability and particle strength, which is excellent in luster and gloss when used as, for example, a powder cosmetic, and which is excellent in concealability when contained as a coloring agent. It is possible to provide rutile-type titanium oxide hollow particles.

1 is a scanning electron microscope (SEM) image of hollow particles obtained in Example 1. FIG. It can be seen from the cracked particles shown near the center that it has a hollow structure. 2 is a scanning electron microscope (SEM) image of hollow particles obtained in Example 1. FIG.

[(A) Non-spherical hollow particles containing titanium oxide]
The present invention relates to (A) hollow particles containing titanium oxide.
Note that titanium oxide has a low photocatalytic function, and (A-1) rutile-type titanium oxide has a higher refractive index than anatase, so that it has even better concealability and is excellent as the hollow particles of the present invention. When a single crystal of rutile-type titanium oxide is used, the ratio of rutile-type titanium oxide in titanium oxide is usually 80% to 100%, preferably 85% to 100%, and more preferably 90% to 100%. In this specification, "-" includes the numerical values before and after. Moreover, the said ratio is a value calculated from an X-ray-diffraction peak.
The term “non-spherical hollow particles” refers to non-spherical particles in which voids are formed inside and whose shells are made of (A) titanium oxide.
In this specification, non-spherical hollow particles may be simply referred to as hollow particles.

[Ratio of major axis diameter to minor axis diameter]
The non-spherical hollow particles of the present invention are characterized by having a ratio of major axis diameter to minor axis diameter (major axis diameter/minor axis diameter) of 1.1 to 10.0. Spherical titanium oxide has been known for some time, but by adjusting the ratio of the major axis diameter to the minor axis diameter to 1.1 to 10.0, the concealability is improved, the slipperiness is improved, and the handling is easy. tend to become In the following description, the ratio of major axis diameter to minor axis diameter may be expressed as aspect ratio.
Here, the major axis diameter means the length of the diameter of the longest axis among the three axes perpendicular to each other of the non-spherical particles, and the minor axis diameter means the length of the diameter of the shortest axis. . Also, the aspect ratio is calculated from the formula of major axis diameter/minor axis diameter.
The major axis diameter and minor axis diameter of the non-spherical particles were obtained by measuring the major axis diameter and minor axis diameter of 20 non-spherical particles randomly photographed with a transmission electron microscope (TEM), respectively, and taken as the arithmetic mean value.
The upper limit of the aspect ratio is 9.0, 8.0, 7.0 and 6.0 in order of preference, and 5.0 is particularly preferred. The lower limits are 1.2, 1.3, 1.4, 1.5, 2.0 and 3.0 in order of preference, with 4.0 being particularly preferred. That is, the aspect ratio is most preferably 4.0 to 5.0.

[Long axis diameter]
The long axis diameter of the non-spherical particles of the present invention is preferably 10 nm or more and 1000 nm or less. Such a range tends to facilitate formation of a hollow structure.
The upper limit of the major axis diameter of the non-spherical particles is more preferably 750 nm, still more preferably 700 nm, and particularly preferably 500 nm. Moreover, as a lower limit, 50 nm is more preferable, 100 nm is still more preferable, and 180 nm is especially preferable. Therefore, 180 nm or more and 500 nm is a particularly preferable range.

[Short axis diameter]
The minor axis diameter of the non-spherical particles of the present invention is not particularly limited as long as the ratio to the major axis diameter satisfies the above 1.1 to 10.0, but it is preferably about 1 nm to 900 nm.
The upper limit of the minor axis diameter of the non-spherical particles is more preferably 700 nm, still more preferably 500 nm, and particularly preferably 300 nm. Moreover, as a lower limit, 10 nm is more preferable, 20 nm is still more preferable, and 30 nm is especially preferable. Therefore, 30 nm or more and 300 nm is a particularly preferable range.

[Coefficient of variation of major axis diameter (CV value)]
The non-spherical particles of the present invention preferably have a variation coefficient of major axis diameter of 10% or less.
The coefficient of variation of the long axis diameter of the non-spherical particles can be calculated from the following formula.
Variation coefficient (%) = standard deviation of major axis diameter (nm) / arithmetic mean major axis diameter (nm)
A smaller coefficient of variation is preferable because it indicates that particles of uniform size are obtained. The coefficient of variation is usually 10% or less, preferably 8% or less, more preferably 7% or less, even more preferably 5% or less, and particularly preferably 4% or less. The lower limit is preferably as small as possible, ideally 0%.

[(B) Silica]
The non-spherical hollow particles of the present invention preferably further contain (B) silica. The silica may be crystalline or amorphous, preferably amorphous. It can be confirmed by a known method that silica is amorphous. Known methods include, for example, a method of measuring diffraction peaks derived from silica crystals (eg, α-SiO ₂ ) using an X-ray diffractometer or the like. As used herein, the term "amorphous" means that no distinct diffraction peaks derived from crystals appear.
Further, when (A) titanium oxide contains silica, the content of titanium oxide is preferably 86.0% by mass or more and 99.5% by mass or less, and more preferably 88.0% by mass or more and 97.5% by mass or less. is more preferably 90.0% by mass or more and 96.5% by mass or less. In addition, the hollow particles according to the present embodiment preferably have a silica content of 0.5% by mass or more and 14.0% by mass or less, more preferably 2.5% by mass or more and 12% by mass or less. , more preferably 3.5% by mass or more and 10% by mass or less. The content of titanium oxide and silica contained in the hollow particles is calculated assuming that the titanium oxide precursor and silica precursor in the production of the hollow particles are converted to titanium oxide and silica at a conversion rate of 100%. When calculating these percentages, round off to the second decimal place and enter the first decimal place.
In the hollow particles, the boundary between the titanium oxide layer having a hollow structure and the silica layer may be a composite oxide. Silica within this range has the advantage of being able to effectively block the transmittance of 400 to 500 nm.

[Shell thickness parameter E/F]
The non-spherical hollow particles of the present invention have an E/F ratio of 0.30 to 0.95, where E is the major axis of the hollow particles and F is the major axis of the non-spherical hollow particles. This means that the thickness of the shell is more than 5% and less than 70% of the particle diameter, and the structure has a hollow inside. Preferred lower limit values of E/F are 0.40, 0.50, 0.60, 0.70, 0.80, 0.85 and 0.86, and particularly preferably 0.90. In addition, the upper limit values are 0.94 and 0.93 in order of preference, and particularly preferably 0.92. That is, the most preferable range of E/F is 0.90 to 0.92. If the thickness of the shell is too thin, the hollow structure may collapse during mixing.
It should be noted that the hollow particles according to this embodiment preferably do not have pores leading from the surface of the particles to the internal pores. Whether or not it has such pores can be determined, for example, by using a pore distribution measuring device (eg, BELSORP-mini II manufactured by Microtrack Bell Co., Ltd.) to measure the amount of adsorption and desorption with respect to relative pressure. can be confirmed by As used herein, "having no pores leading to internal pores" means that the adsorption-desorption isotherm created from the adsorption and desorption amounts is not type IV or type V in the IUPAC classification. . Within the IUPAC classification, Types II and III are preferred, with Type II being more preferred.

<Other Configurations of Hollow Particles>
The non-spherical hollow particles according to the present embodiment include, in addition to titanium oxide, the above silica, and further, for example, Sn, Cd, Fe, Ni, Zn, Mn, Co, Cr, Cu, K, Na, Li, P , S, and the like. These elements may be of one type or two or more types.

When the hollow particles according to the present embodiment further contain elements other than titanium oxide and silica, the total content of these elements is usually from 0.1 mol% to the number of moles of titanium in titanium oxide. 15 mol %, preferably 0.1 mol % to 10 mol %, more preferably 0.1 mol % to 5 mol %. By setting it to such a range, there is a tendency to easily obtain hollow particles with little coloring (that is, high whiteness).

The hollow particles according to this embodiment may further have a layer of other substance on the surface, if necessary. Other substances include, for example, alumina, aluminum hydroxide, zinc oxide, zinc hydroxide, zirconia, organic substances, and the like.

The hollow particles according to the present embodiment are useful in various applications such as white pigments for white ink, light scattering agents or light scattering aids in powdered cosmetics, and the like.

<Method for producing non-spherical hollow particles>
Hollow particles according to the present embodiment are disclosed, for example, in Xiong Wen (David) Lou, Lynden A.; Archer and Zichao Yang, Adv. Mater. , 2008, 20, 3987-4019 and the like. However, it is not limited to this manufacturing method.

Unless otherwise specified, each step described below is preferably carried out under stirring.

(Production of non-spherical core-shell particles)
A step of reacting the ellipsoidal organic particles with titanium alkoxide and optionally other metal alkoxide in an organic solvent in the presence of a base is included. Only one type of metal alkoxide may be used, or two or more types may be used. When two or more kinds of metal alkoxides are used, they may be added one by one or may be added at the same time. A shell of an inorganic compound obtained from the metal alkoxide is formed on the surface of the core ellipsoidal organic particle. non-spherical core-shell particles can be obtained.

[Ellipsoidal organic particles]
Examples of ellipsoidal organic particles include polymer particles and low-molecular-weight compounds. Specific examples of polymer particles include polymer particles obtained by polymerizing at least one monomer selected from (meth)acrylate, vinyl, styrene, and urethane monomers. Among these, polymer particles containing styrene as a constituent monomer are preferred, styrene-(meth)acrylic acid polymer particles are more preferred, and styrene-methacrylic acid polymer particles are particularly preferred.
In this specification, "(meth)acrylate" means both acrylate and methacrylate, and "(meth)acrylic acid" means both acrylic acid and methacrylic acid.
A low-molecular-weight compound means a compound having a weight average molecular weight of less than 1000, and compounds that form spherical micelles or rod-like micelles in the reaction medium can be used. Specifically, anionic surfactants: sodium lauryl sulfate, sodium (poly)oxyethylene lauryl sulfate and triethanolamine (poly)oxyethylene lauryl sulfate, cationic surfactants: stearyltrimethylammonium chloride, diethylamino stearate Ethylamide lactate, dilaurylamine hydrochloride and oleylamine lactate, etc. Nonionic surfactants: diethanolamine adipate condensate, lauryl dimethylamine oxide, glyceryl monostearate, sorbitan monolaurate and diethylaminoethylamide lactate stearate, etc. , and amphoteric surfactants: coconut fatty acid amidopropyldimethylaminoacetate betaine, lauryl hydroxysulfobetaine and sodium β-laurylaminopropionate.

[Method of Polymerizing Polymer Particles]
The polymerization method for obtaining polymer particles is not particularly limited, but dispersion polymerization, emulsion polymerization, soap-free emulsion polymerization (emulsion polymerization that does not use a surfactant as an emulsifier), seed polymerization, suspension polymerization, etc. may be used. can be done. In order to obtain polymer particles of uniform particle size, it is necessary to first use seed particles of uniform particle size and grow these seed particles substantially uniformly. Seed particles having a uniform particle size as a raw material can be prepared by polymerizing by a polymerization method such as soap-free emulsion polymerization (emulsion polymerization that does not use a surfactant) or dispersion polymerization. Therefore, the emulsion polymerization method, the soap-free emulsion polymerization method, the seed polymerization method and the dispersion polymerization method are preferable as the polymerization method for obtaining polymer particles having a uniform particle size and a small coefficient of variation. A soap-free emulsion polymerization method is more preferable from the viewpoint of easy production of particles of several hundred nanometers.

Also in the polymerization for obtaining seed particles, a polymerization initiator is used as necessary. Examples of the polymerization initiator include persulfates such as potassium persulfate, ammonium persulfate and sodium persulfate; benzoyl peroxide, lauroyl peroxide, o-chlorobenzoyl peroxide, o-methoxybenzoyl peroxide, 3,5 , 5-trimethylhexanoyl peroxide, tert-butylperoxy-2-ethylhexanoate, di-tert-butyl peroxide and other organic peroxides; 2,2'-azobisisobutyronitrile, 1, Azo compounds such as 1′-azobiscyclohexanecarbonitrile, 2,2′-azobis(2,4-dimethylvaleronitrile), and the like. The amount of the polymerization initiator to be used is preferably in the range of 0.1 to 3 parts by weight per 100 parts by weight of the constituent monomers used to obtain the seed particles. The weight average molecular weight of the obtained seed particles can be adjusted by adjusting the amount of the polymerization initiator used.

In the polymerization for obtaining seed particles, a molecular weight modifier may be used to adjust the weight average molecular weight of the resulting seed particles. Examples of the molecular weight modifier include mercaptans such as n-octylmercaptan and tert-dodecylmercaptan; α-methylstyrene dimer; terpenes such as γ-terpinene and dipentene; halogenated hydrocarbons such as chloroform and carbon tetrachloride; can be used. The weight average molecular weight of the obtained seed particles can be adjusted by adjusting the amount of the molecular weight modifier used.

[Ellipsoid deformation method of polymer particles]
There are no particular restrictions on the method of making polymer particles ellipsoidal, but examples include roll mills, bead mills, jet mills, rotary mills, hammer mills, pin mills, vibration mills, planetary mills, attritors, ring mills, cutter mills, cone crushers, and rolls. Methods of mechanical deformation such as crusher, jaw crusher, gyratory crusher, and impact crusher can be mentioned. It can also be transformed using a mortar, stone mill, or mortar machine.
Roll mills, bead mills, jet mills, rotary mills, hammer mills, pin mills, vibration mills, planetary mills and attritors are preferred as methods for efficiently forming fine polymer particles into ellipsoids, and bead mills and attritors are more preferred. Furthermore, a bead mill is particularly preferred from the viewpoint of ease of production.

By controlling the amount of titanium alkoxide added, the thickness of the shell can be controlled. The metal alkoxide may be added at once or in several batches in an amount necessary for the shell to have a specific thickness. By adding the titanium oxide precursor in several batches, the thickness of the shell tends to be more uniform.

Examples of organic solvents include hydrocarbon solvents (toluene, xylene, hexane, cyclohexane, n-heptane, etc.), alcohol solvents (methanol, ethanol, isopropyl alcohol, butanol, t-butanol, benzyl alcohol, etc.), ketone solvents, Solvents (acetone, methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, acetylacetone, etc.), ester solvents (ethyl acetate, methyl acetate, butyl acetate, cellosolve acetate, amyl acetate, etc.), ether solvents (isopropyl ether, methyl cellosolve, butyl cellosolve, tetrahydrofuran, 1,4-dioxane, etc.), glycol solvents (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, octylene glycol, etc.), glycol ether solvents (diethylene glycol monomethyl ether, propylene glycol monomethyl ether, etc.), Glycol ester solvents (ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, etc.), glyme solvents (monoglyme, diglyme, etc.), halogen solvents (dichloromethane, chloroform, etc.), amide solvents (N , N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone), pyridine, sulfolane, acetonitrile, dimethylsulfoxide and the like.

An organic solvent may be used individually by 1 type, and may use 2 or more types together. By using two or more kinds of organic solvents in combination and controlling the ratio thereof, the concentration of the ellipsoidal organic particles, the method of adding the base, and the like, it is possible to maintain a good dispersion state of the reaction solution.

Bases include inorganic bases and organic bases. Examples of inorganic bases include hydroxides of Group 1 or Group 2 elements of the periodic table, preferably hydroxides of Na, K, Ca, Mg, Al, Fe and the like; ammonia; and the like. Examples of organic bases include heteroaromatic ring compounds such as pyridine; alkylamines such as triethylamine (preferably trialkylamines, more preferably triC1-C4 alkylamines); hydroxyalkylamines such as triethanolamine (preferably trialkylamines). (hydroxyalkyl)amine, more preferably tri(hydroxy C1-C4 alkylamine)); and the like.

The non-spherical core-shell particles are preferably produced in an inert gas atmosphere such as nitrogen or argon.
The reaction temperature for the production of non-spherical core-shell particles is usually -30°C to 80°C, preferably 0°C to 50°C.
The reaction time for producing non-spherical core-shell particles varies depending on the reaction temperature, the thickness of the shell, and the like, so it is difficult to categorically determine the reaction time. As a standard, it is usually 0.1 hour to 10 hours, preferably about 0.5 hour to 7 hours.

When the ellipsoidal organic particles are polymer particles and the surface potential thereof has the same sign as that of the inorganic compound, core-shell particles can also be formed by the following method.
That is, an organic polymer (for example, polyethyleneimine, etc.) having a sign opposite to the above surface potential is adsorbed on the surface of the polymer particles. Core-shell particles can then be formed by depositing or adsorbing fine particles of an inorganic compound onto the surface of the polymer particles and optionally adding a metal alkoxide. When the fine particles of the inorganic compound are titanium oxide, for example, by using rutile-type titanium oxide, the crystal form of the titanium oxide of the shell can be made rutile-type.

The production of non-spherical core-shell particles is carried out in a dispersion state. Therefore, in order to improve the dispersion stability of the dispersion, the first step is preferably carried out in the presence of a dispersant. The type of dispersant is not particularly limited as long as it does not interfere with shell formation. Examples of such dispersants include polyalkylene glycols such as polyethylene glycol and polypropylene glycol; polyvinylpyrrolidone; Floren series manufactured by Kyoeisha Chemical Co., Ltd.; DISPERBYK series manufactured by BYK-Chemie Japan; Solspers series; Ajinomoto Fine-Techno Co., Inc. Ajisper series; Kusumoto Kasei Co., Ltd. Disparlon series;

[Method 1 for producing non-spherical hollow particles]
A production method for obtaining the non-spherical hollow particles (D) by dissolving and removing the ellipsoidal organic particles, which are the cores of the non-spherical core-shell particles, with a solvent is exemplified. As such a solvent, a solvent that does not dissolve or destroy the shell particles is preferred. Solvents to be used include organic solvents such as methyl ethyl ketone, toluene, tetrahydrofuran and chloroform, and aqueous solutions of acids such as dilute hydrochloric acid, dilute nitric acid and dilute sulfuric acid.
After removing the ellipsoidal organic particles, baking may be performed.

[Method 2 for producing non-spherical hollow particles]
A step of obtaining non-spherical hollow particles by removing ellipsoidal organic particles, which are the cores of non-spherical core-shell particles, by pyrolysis can be mentioned. In the process of firing the non-spherical core-shell particles, the removal of the ellipsoidal organic particles and the firing of the shell layer can be performed at the same time. Generally, the firing can be performed in an atmosphere of a gas selected from one or more of air, nitrogen, argon, hydrogen, ammonia, etc. However, in order to obtain single-crystal titanium oxide, the firing must be performed in an air atmosphere. preferably. As used herein, the term "air" refers to the gas that constitutes the lowest layer of the earth's atmosphere and is obtained in the normal environment in which humans live.

The sintering temperature in the production of non-spherical hollow particles varies depending on the material of the hollow particles and the like, so it is difficult to determine indiscriminately. As a guideline, it is usually 600°C to 1500°C or less, preferably 650°C to 1400°C, more preferably 700°C to 1300°C, and still more preferably about 750°C to 1200°C.
Moreover, since the firing time varies depending on the firing temperature and the like, it is difficult to determine it unconditionally. As a guideline, it is usually 0.5 hours to several tens of hours, preferably about 1 hour to 10 hours.

In the production of non-spherical particles, non-uniformly shaped by-product particles may be included. The proportion of by-product particles is usually 10% or less, preferably 5% or less. Generation of by-product particles can be suppressed by, for example, precisely controlling the synthesis conditions. The content of by-products can be calculated from the number of non-uniformly shaped particles among 100 hollow particles randomly photographed with a transmission electron microscope (TEM) or scanning electron microscope (SEM). can.

<Dispersion>
The dispersion of the present invention contains (I) non-spherical hollow particles and (II) a solvent.
The content of (I) non-spherical hollow particles is preferably 1 to 60% by mass with respect to the total mass of the dispersion of the present invention. The upper limit of the content is more preferably 40% by mass, still more preferably 30% by mass, and particularly preferably 25% by mass. Moreover, as a lower limit, 5 mass % is more preferable, 8 mass % is still more preferable, and 10 mass % is especially preferable. Therefore, the content of (I) the non-spherical hollow particles is most preferably 10% by mass or more and 25% by mass or less.
[(II) Solvent]
The solvent may be water-soluble or water-insoluble.
Examples of water-insoluble solvents include hydrocarbon solvents (toluene, xylene, hexane, cyclohexane, n-heptane, etc.), ketone solvents (methyl ethyl ketone, methyl isobutyl ketone, diisobutyl ketone, cyclohexanone, acetylacetone, etc.), and ester solvents. (ethyl acetate, methyl acetate, butyl acetate, cellosolve acetate, amyl acetate, etc.), ether solvents (isopropyl ether, methyl cellosolve, butyl cellosolve, 1,4-dioxane, etc.), glycol ether solvents (diethylene glycol monomethyl ether, propylene glycol monomethyl ether, etc.), glycol ester solvents (ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, etc.), glyme solvents (monoglyme, diglyme, etc.), halogen solvents (dichloromethane, chloroform, etc.), tetrahydrofuran is mentioned.
Examples of water-soluble solvents include C1-C6 alcohols such as methanol, ethanol, propanol, isopropanol, butanol, isobutanol, sec-butanol and tert-butanol; N,N-dimethylformamide, N,N-dimethylacetamide and the like. Carboxylic acid amide; Lactam such as 2-pyrrolidone, N-methyl-2-pyrrolidone, N-methylpyrrolidin-2-one; 1,3-dimethylimidazolidin-2-one, 1,3-dimethylhexahydropyrimido- Cyclic ureas such as 2-one; ketones or ketoalcohols such as acetone, 2-methyl-2-hydroxypentan-4-one, ethylene carbonate; cyclic ethers such as tetrahydrofuran and dioxane; ethylene glycol, diethylene glycol, 1,2 -propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,2-hexanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, diethylene glycol, C2-C6 diols such as propylene glycol, polyethylene glycol with a molecular weight of 400, 800, 1540 or higher, polypropylene glycol, thiodiglycol, dithiodiglycol, or mono-, oligo- or polyalkylene glycols having C2-C6 alkylene units or thioglycol; polyols (triols) such as glycerin, diglycerin, hexane-1,2,6-triol and trimethylolpropane; dimethyl sulfoxide; propylene glycol monomethyl ether, ethylene glycol monomethyl ether acetate, ethylene glycol monoethyl ether acetate, Ethylene glycol monobutyl ether acetate, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate, propylene glycol monomethyl ether acetate, dipropylene glycol monomethyl ether acetate, ethylene glycol monomethyl ether propionate, ethylene glycol monoethyl ether propio ethylene glycol monobutyl ether propionate, diethylene glycol monomethyl ether propionate, propylene glycol monomethyl ether propionate, dipropylene glycol monomethyl ether propionate, ethylene glycol monomethyl ether butyrate, ethylene glycol monoethyl ether butyrate, ethylene glycol monobutyl ether butyrate, diethylene glycol monomethyl ether butyrate, diethylene glycol monoethyl ether butyrate, diethylene glycol monobutyl ether butyrate, propylene glycol Glycol ethers such as monomethyl ether butyrate and dipropylene glycol monomethyl ether butyrate, or glycol ether acetates;

The above water-soluble organic solvents also include substances that are solid at room temperature, such as trimethylolpropane. However, even if the substance or the like is solid, it exhibits water solubility, and an aqueous solution containing the substance or the like exhibits properties similar to those of a water-soluble organic solvent, and can be used with the expectation of the same effect. For this reason, in the present specification, for the sake of convenience, even such solid substances are included in the category of water-soluble organic solvents as long as they can be used with the expectation of the same effect as described above.

Preferred water-soluble organic solvents include isopropanol, glycerin, mono-, di-, triethylene glycol, dipropylene glycol, 2-pyrrolidone, hydroxyethyl-2-pyrrolidone, N-methyl-2-pyrrolidone, trimethylolpropane, and butyl carbitol, more preferably isopropanol, glycerin, diethylene glycol, 2-pyrrolidone, N-methyl-2-pyrrolidone, and butyl carbitol. These water-soluble organic solvents are used singly or in combination.
The content of the solvent (B) is preferably 1 to 90% by weight relative to the total weight of the dispersion of the present invention. In addition, when the content is less than 100% by mass together with the rutile-type titanium oxide hollow particles (A), the remainder is water or the following dispersant, additive, and the like.
The upper limit of the content is more preferably 80% by mass, still more preferably 60% by mass, and particularly preferably 40% by mass. Moreover, as a lower limit, 10 mass % is more preferable, 20 mass % is still more preferable, and 30 mass % is especially preferable. Therefore, the most preferable content of (B) the solvent is 30% by mass or more and 40% by mass or less.

[(III) Dispersant]
The dispersion of the present invention preferably further contains (III) a dispersant.
vinylnaphthalene and its derivatives; aliphatic alcohol esters of α,β-ethylenically unsaturated carboxylic acids; acrylic acid and its derivatives; maleic acid and its derivatives; itaconic acid and its derivatives. fumaric acid and derivatives thereof; vinyl acetate, vinyl alcohol, vinylpyrrolidone, acrylamide, and derivatives thereof; The obtained copolymer is mentioned. Types of copolymers include, for example, block copolymers, random copolymers, graft copolymers, and salts thereof.
Dispersants can be synthesized or obtained commercially.
Specific examples of commercially available products include Joncryl 62, 67, 68, 678, 687 (styrene-acrylic resin manufactured by BASF); Movinyl S-100A (modified vinyl acetate resin manufactured by Hoechst Synthesis); Julimer AT-210 (polyacrylic acid ester copolymer manufactured by Nippon Junyaku Co., Ltd.); DISPERBYK series manufactured by BYK-Chemie Japan Co., Ltd. (eg, DISPERBYK-2010); and the like.
When synthesizing a dispersant, the dispersant disclosed in WO 2013/115071 is preferably mentioned.

[Other ingredients]
The dispersion of the present invention contains water as other components, and known additives such as surfactants, antiseptic agents, pH adjusters, chelating reagents, rust inhibitors, ultraviolet absorbers, viscosity adjusters, and dye solubilizers. , an antifading agent, an antifoaming agent, and the like can be used.

When water is used, water that can be used is not limited, but water containing few impurities such as inorganic ions is preferable. Examples of such water include ion-exchanged water, distilled water, and the like.
The water content is 0 to 90% by weight, preferably 10 to 80% by weight, relative to the total weight of the dispersion of the invention.

Examples of surfactants include known surfactants such as anionic, cationic, nonionic, amphoteric, silicone-based, and fluorine-based surfactants. Among these, nonionic surfactants and silicone surfactants are preferred, and silicone surfactants are more preferred.
Examples of anionic surfactants include alkylsulfocarboxylates, α-olefin sulfonates, polyoxyethylene alkyl ether acetates, polyoxyethylene alkyl ether sulfates, N-acyl amino acids or salts thereof, and N-acyl methyl taurates. , alkyl sulfate polyoxyalkyl ether sulfate, alkyl sulfate polyoxyethylene alkyl ether phosphate, rosin acid soap, castor oil sulfate, lauryl alcohol sulfate, alkylphenol type phosphate, alkyl type phosphate , alkylarylsulfonate, diethylsulfosuccinate, diethylhexylsulfosuccinate, dioctylsulfosuccinate, and the like.
Cationic surfactants include 2-vinylpyridine derivatives, poly-4-vinylpyridine derivatives and the like.
Nonionic surfactants include ether-based surfactants such as polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene lauryl ether, and polyoxyethylene alkyl ether; Esters such as polyoxyethylene oleate, polyoxyethylene distearate, sorbitan laurate, sorbitan monostearate, sorbitan monooleate, sorbitan sesquioleate, polyoxyethylene monooleate, polyoxyethylene stearate; 2,4,7,9-tetramethyl-5-decyne-4,7-diol, 3,6-dimethyl-4-octyne-3,6-diol, 3,5-dimethyl-1-hexyn-3-ol acetylene glycol (alcohol)-based, and C2-C4 alkyleneoxy adducts thereof; polyglycol ether-based;
Amphoteric surfactants include lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, polyoctylpolyaminoethylglycine, imidazoline derivatives, and the like. is mentioned.
Examples of silicone-based surfactants include polyether-modified siloxane and polyether-modified polydimethylsiloxane. Examples thereof include Dynor 960 and Dynor 980 manufactured by Air Products; Silface SAG001, Silface SAG002, Silface SAG003, Silface SAG005, Silface SAG503A, Silface SAG008, and Silface SAG009 manufactured by Nissin Chemical Co., Ltd. , Silface SAG010; BYK-345, BYK-347, BYK-348, BYK-349, BYK-3455 manufactured by BYK-Chemie; Among these, polyether-modified siloxanes known as the BYK series manufactured by BYK-Chemie are preferred.
Examples of fluorine-based surfactants include perfluoroalkylsulfonic acid compounds, perfluoroalkylcarboxylic acid compounds, perfluoroalkylphosphoric acid ester compounds, perfluoroalkylethylene oxide adducts, and poly(polyethylene) having a perfluoroalkyl ether group in the side chain. oxyalkylene ether polymer compounds and the like. Various types of fluorosurfactants can be easily purchased from DuPont, Omnova, DIC, BYK-Chemie, and the like.
The surfactant content is 0 to 20% by weight, preferably 5 to 15% by weight, relative to the total weight of the dispersion of the invention.

Examples of the above antiseptic and antifungal agents include organic sulfur, organic nitrogen sulfur, organic halogen, haloarylsulfone, iodopropargyl, N-haloalkylthio, benzothiazole, nitrile, pyridine, 8-oxyquinoline, isothiazoline, dithiol, pyridine oxide, nitropropane, organic tin, phenol, quaternary ammonium salt, triazine, thiadiazine, anilide, adamantane, dithiocarbamate, bromine Indanone-based compounds, benzylbromoacetate-based compounds, inorganic salt-based compounds, and the like can be mentioned.
Examples of organic halogen compounds include sodium pentachlorophenol, and examples of pyridine oxide compounds include sodium 2-pyridinethiol-1-oxide.
Examples of isothiazolin compounds include 1,2-benzisothiazolin-3-one, 2-n-octyl-4-isothiazolin-3-one, 5-chloro-2-methyl-4-isothiazolin-3-one, 5 -chloro-2-methyl-4-isothiazolin-3-one magnesium chloride, 5-chloro-2-methyl-4-isothiazolin-3-one calcium chloride, 2-methyl-4-isothiazolin-3-one calcium chloride, etc. mentioned.
Other antiseptic and antifungal agents include sodium acetate, sodium sorbate, sodium benzoate and the like; and Proxel ^RTM GXL (S) and Proxel ^RTM XL-2 (S) manufactured by Arch Chemicals, respectively. mentioned. In this specification, the superscript "RTM" means a registered trademark.

Any substance can be used as the pH adjuster as long as it can control the pH in the range of 6.0 to 11.0 for the purpose of improving the storage stability of the dispersion. For example, alkanolamines such as diethanolamine and triethanolamine; alkali metal hydroxides such as lithium hydroxide, sodium hydroxide and potassium hydroxide; ammonium hydroxide; or alkali metal hydroxides such as lithium carbonate, sodium carbonate and potassium carbonate. carbonates; aminosulfonic acids such as taurine; and the like.

Chelating agents include, for example, disodium ethylenediaminetetraacetate, sodium nitrilotriacetate, sodium hydroxyethylethylenediaminetriacetate, sodium diethylenetriaminepentaacetate, sodium uracil diacetate and the like.

Examples of rust preventives include acidic sulfites, sodium thiosulfate, ammonium thioglycolate, diisopropylammonium nitrite, pentaerythritol tetranitrate, and dicyclohexylammonium nitrite.

Examples of ultraviolet absorbers include benzophenone compounds, benzotriazole compounds, cinnamic acid compounds, triazine compounds, and stilbene compounds. A compound that absorbs ultraviolet light and emits fluorescence, such as a benzoxazole-based compound, that is, a so-called fluorescent whitening agent can also be used.

Viscosity modifiers include water-soluble organic solvents as well as water-soluble polymer compounds such as polyvinyl alcohol, cellulose derivatives, polyamines and polyimines.

Antifading agents are used for the purpose of improving the storage stability of images. As the antifading agent, various organic and metal complex antifading agents can be used. Examples of organic antifading agents include hydroquinones, alkoxyphenols, dialkoxyphenols, phenols, anilines, amines, indanes, chromans, alkoxyanilines, and heterocycles. , nickel complexes, zinc complexes, and the like.

Antifoaming agents include highly oxidized oil-based, glycerin fatty acid ester-based, fluorine-based, and silicone-based compounds.

The dispersion liquid of the present invention can also be made into a resin composition using a binder resin. Furthermore, this resin composition may contain a thermosetting agent and/or a radical polymerization initiator.

The binder resin is not particularly limited, and low-molecular-weight compounds such as acrylic monomers are also referred to as binder resins in this specification as long as they can be used as binders.
Thermoplastic resins that can be used as binder resins include high-density polyethylene resins, low-density polyethylene resins, linear low-density polyethylene resins, ultra-low-density polyethylene resins, polypropylene resins, polybutadiene resins, cyclic olefin resins, and polymethylpentene resins. , polystyrene resin, ethylene vinyl acetate copolymer, ionomer resin, ethylene vinyl alcohol copolymer resin, ethylene ethyl acrylate copolymer, acrylonitrile/styrene resin, acrylonitrile/chlorinated polystyrene/styrene copolymer resin, acrylonitrile/acrylic rubber/styrene copolymer Polymeric resins, acrylonitrile-butadiene-styrene copolymer resins, acrylonitrile-EPDM-styrene copolymer resins, silicone rubber-acrylonitrile-styrene copolymer resins, cellulose-acetate-butyrate resins, cellulose acetate resins, methacrylic resins, ethylene-methyl methacrylate copolymers resin, ethylene/ethyl acrylate resin, vinyl chloride resin, chlorinated polyethylene resin, polytetrafluoroethylene resin, tetrafluoroethylene/hexafluoropropylene copolymer resin, tetrafluoroethylene/perfluoroalkyl vinyl ether copolymer resin, Tetrafluoroethylene/ethylene copolymer resin, polytrifluoroethylene chloride resin, polyvinylidene fluoride resin, nylon 4,6, nylon 6, nylon 6,6, nylon 6,10, nylon 6,12, nylon 12, nylon 6, T, nylon 9, T, aromatic nylon resin, polyacetal resin, ultra-high molecular weight polyethylene resin, polybutylene terephthalate resin, polyethylene terephthalate resin, polyethylene naphthalate resin, amorphous copolyester resin, polycarbonate resin, modified polyphenylene ether Resin, thermoplastic polyurethane elastomer, polyphenylene sulfide resin, polyetheretherketone resin, liquid crystal polymer, polytetrafluoroethylene resin, polyfluoroalkoxy resin, polyetherimide resin, polysulfone resin, polyketone resin, thermoplastic polyimide resin, polyamideimide resin , polyarylate resins, polysulfone resins, polyethersulfone resins, biodegradable resins, biomass resins, and the like. However, it is not limited to these. A mixture of two or more of these resins may also be used. The weight average molecular weight of these thermoplastic resins is about 1000 to 1,000,000, preferably about 2000 to 500,000, more preferably about 2000 to 200,000. A resin that is preferable as a thermoplastic resin is preferably a (meth)acrylic resin from the viewpoint of transparency and the like, and for example, a (meth)acrylate polymer, particularly a (meth)acrylic copolymer, and the like are preferable.

Thermosetting resins that can be used as binder resins include, for example, curable compounds having cyclic ethers such as epoxy groups and oxetanyl groups.
The thermosetting resin having a cyclic ether is not particularly limited, and examples thereof include epoxy resins (aliphatic epoxy resins including alicyclic epoxy resins or aromatic epoxy resins), oxetane resins, furan resins, and the like. Among them, epoxy resins (which may contain an aliphatic ring, for example, an aliphatic ring having 3 to 12 carbon atoms) and oxetane resins are preferable from the viewpoint of reaction rate and versatility. The epoxy resin is not particularly limited, and examples thereof include novolak types such as phenol novolak type, cresol novolak type, biphenyl novolak type, trisphenol novolak type, and dicyclopentadiene novolak type; bisphenol A type, bisphenol F type, 2,2 '-diallyl bisphenol A type, hydrogenated bisphenol type, bisphenol type such as polyoxypropylene bisphenol A type, and the like. Other examples include glycidylamine and the like.
Examples of commercially available epoxy resins include, for example, phenolic novolac type epoxy resins such as Epiclon (registered trademark) N-740, N-770, and N-775 (all of which are manufactured by Dainippon Ink and Chemicals); Epikote (registered trademark) 152, Epikote (registered trademark) 154 (both of which are manufactured by Japan Epoxy Resin Co., Ltd.), and the like. Examples of cresol novolak type include Epiclon (registered trademark) N-660, N-665, N-670, N-673, N-680, N-695, N-665-EXP, N-672-EXP (above , both manufactured by Dainippon Ink and Chemicals Co., Ltd.); biphenyl novolac type, for example, NC-3000P (manufactured by Nippon Kayaku Co., Ltd.); Epoxy Resin Co., Ltd.); dicyclopentadiene novolac type, for example, XD-1000-L (manufactured by Nippon Kayaku Co., Ltd.), HP-7200 (manufactured by Dainippon Ink and Chemicals Co., Ltd.); bisphenol A type epoxy compound As, for example, Epicort (registered trademark) 828, Epicort (registered trademark) 834, Epicort 1001, Epicort (registered trademark) 1004 (all manufactured by Japan Epoxy Resin Co., Ltd.), Epiclon (registered trademark) 850, Epiclon ( Registered trademark) 860, Epiclon (registered trademark) 4055 (both manufactured by Dainippon Ink and Chemicals Co., Ltd.); commercial products of bisphenol F type epoxy compounds include, for example, Epicort (registered trademark) 807 (Japan Epoxy Resin Co., Ltd. company), Epiclon (registered trademark) 830 (manufactured by Dainippon Ink and Chemicals Co., Ltd.); 2,2'-diallyl bisphenol A type, for example, RE-810NM (manufactured by Nippon Kayaku Co., Ltd.); hydrogenated bisphenol Examples of the type include ST-5080 (manufactured by Tohto Kasei Co., Ltd.); examples of the polyoxypropylene bisphenol A type include EP-4000 and EP-4005 (both of which are manufactured by Asahi Denka Kogyo Co., Ltd.). be done.
Examples of commercially available oxetane compounds include Ethanacol (registered trademark) EHO, Ethanacol (registered trademark) OXBP, Ethanacol (registered trademark) OXTP, and Ethanacol (registered trademark) OXMA (all of which are manufactured by Ube Industries, Ltd.). mentioned. The alicyclic epoxy compound is not particularly limited, and examples thereof include Celoxide (registered trademark) 2021, Celoxide (registered trademark) 2080, and Celoxide (registered trademark) 3000 (all manufactured by Daicel-UCB Co., Ltd.). etc. These curable compounds having a cyclic ether group may be used alone, or two or more of them may be used in combination.

Examples of photocurable resins that can be used as binder resins include resins having a vinyl group, a vinyl ether group, an allyl group, a maleimide group, a (meth)acryloyl group, and the like. Among them, a resin having a (meth)acryloyl group, such as a (meth)acrylate compound, is preferable from the viewpoint of reactivity and versatility. In this specification, terms such as "(meth)acryloyl" mean "acryloyl" or "methacryloyl," for example, "(meth)acrylate" means "acrylate" or "methacrylate."
Examples of resins having a (meth)acryloyl group include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 1,4-butanediol mono(meth)acrylate, carbitol (meth)acrylate, acryloyl Morpholine, half ester which is reaction product of hydroxyl group-containing (meth)acrylate and acid anhydride of polycarboxylic acid compound, polyethylene glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate , trimethylolpropane polyethoxytri(meth)acrylate, glycerin polypropoxytri(meth)acrylate, di(meth)acrylate of ε-caprolactone adduct of neopentylglycol hydroxypivalate (for example, manufactured by Nippon Kayaku Co., Ltd., KAYARAD (registered trademark) HX-220, HX-620, etc.), pentaerythritol tetra (meth) acrylate, dipentaerythritol and ε-caprolactone reaction product poly (meth) acrylate, dipentaerythritol poly (meth) acrylate (for example, Japan Kayaku Co., Ltd., KAYARAD (registered trademark) DPHA, etc.), and (meth)acrylate compounds such as epoxy (meth)acrylate which is a reaction product of a mono- or polyglycidyl compound and (meth)acrylic acid.
The glycidyl compound used in epoxy (meth)acrylate, which is a reaction product of a mono- or polyglycidyl compound and (meth)acrylic acid, is not particularly limited. biphenylphenol, tetramethylbisphenol A, dimethylbisphenol A, tetramethylbisphenol F, dimethylbisphenol F, tetramethylbisphenol S, dimethylbisphenol S, tetramethyl-4,4'-biphenol, dimethyl-4,4'-biphenylphenol, 1-(4-hydroxyphenyl)-2-[4-(1,1-bis-(4-hydroxyphenyl)ethyl)phenyl]propane, 2,2′-methylene-bis(4-methyl-6-tert- butylphenol), 4,4′-butylidene-bis(3-methyl-6-tert-butylphenol), trishydroxyphenylmethane, resorcinol, hydroquinone, pyrogallol, phenols having a diisopropylidene skeleton, 1,1-di-4 -phenols having a fluorene skeleton such as hydroxyphenylfluorene, phenolized polybutadiene, brominated bisphenol A, brominated bisphenol F, brominated bisphenol S, brominated phenol novolak, brominated cresol novolac, chlorinated bisphenol S, chlorinated bisphenol Glycidyl etherified products of polyphenols such as A can be mentioned.
Epoxy(meth)acrylate, which is a reaction product of these mono- or polyglycidyl compounds and (meth)acrylic acid, can be obtained by subjecting the epoxy group to an esterification reaction with an equivalent amount of (meth)acrylic acid. This synthetic reaction can be carried out by a generally known method. For example, an equivalent amount of (meth)acrylic acid is added to resorcinol diglycidyl ether, a catalyst (e.g., benzyldimethylamine, triethylamine, benzyltrimethylammonium chloride, triphenylphosphine, triphenylstibine, etc.) and a polymerization inhibitor (e.g., methoquinone, hydroquinone, methylhydroquinone, phenothiazine, dibutylhydroxytoluene, etc.) to carry out an esterification reaction at, for example, 80 to 110.degree. The (meth)acrylated resorcinol diglycidyl ether thus obtained is a resin having a radically polymerizable (meth)acryloyl group.

As the binder resin, a thermosetting resin or a photo-setting resin is preferred, and a photo-setting resin is more preferred.
Moreover, it is particularly preferable to use a binder resin having three or more (meth)acryloyl groups in the molecule.
Binder resins having three or more (meth)acryloyl groups and polar functional groups in the molecule include, for example, pentaerythritol triacrylate (KAYARAD PET-30 manufactured by Nippon Kayaku), dipentaerythritol pentaacrylate and dipentaeryth. Little hexaacrylate mixture (KAYARAD DPHA manufactured by Nippon Kayaku), 2-hydroxy-3-acryloyloxypropyl methacrylate (701A manufactured by Shin-Nakamura Chemical), ethoxylated isocyanuric acid triacrylate (A-9300 manufactured by Shin-Nakamura Chemical), ε -Caprolactone-modified tris-(2-acryloxyethyl) isocyanurate (A-9300-1CL Shin-Nakamura Chemical) and other (meth)acrylate monomer compounds, bisphenol A type epoxy acrylates (R-115F, R-130, R-381 Epoxy acrylate resins such as Nippon Kayaku), bisphenol F type epoxy acrylate (ZFA-266H Nippon Kayaku), acid-modified epoxy acrylate (ZAR series, ZCR series Nippon Kayaku), polyester urethane acrylate (UX3204, UX-4101, UXT-6100 Nippon Kayaku), mixed urethane acrylate (UX-6101, UX-8101 Nippon Kayaku), polyether urethane acrylate (UX-937, UXF-4001-M35 Nippon Kayaku) ), and urethane acrylate resins such as ester urethane acrylates (DPHA-40H, UX-5000, UX-5102D-M20, UX-5103D, UX-5005 manufactured by Nippon Kayaku).
The binder resin having 3 or more (meth)acryloyl groups in the molecule preferably has 3 or more and 10 or less (meth)acryloyl groups, and more preferably 4 or more and 8 or less (meth)acryloyl groups. is the case with
The content of the binder resin is 0 to 50% by weight, preferably 5 to 40% by weight, based on the total weight of the dispersion of the invention.

When a thermosetting resin is used as the binder resin, a thermosetting agent is preferably used, and when a photocurable resin is used, a photoinitiator is preferably used. However, since the photocurable resin is cured by a radical polymerization reaction of unsaturated double bonds, a thermal radical polymerization initiator can be used in the same way.

The heat curing agent that can be used is one that reacts nucleophilically with a lone pair of electrons or an anion in the molecule, such as an amine curing agent (hereinafter also referred to as amines), a hydrazide curing agent (hereinafter referred to as hydrazides), imidazole-based curing agents (hereinafter also referred to as imidazoles), polyamide resins, dicyandiamide, isocyanates, thiol-based curing agents (thiols), phenol-based curing agents (phenols), and the like. However, it is not limited to these.
Examples of amines include aliphatic chain amines, aliphatic cyclic amines, aromatic amines, and modified amines (amine adducts, ketimine, etc.). Any of primary amines, secondary amines, tertiary amines and quaternary amines may be used, but primary or secondary amines are preferred from the viewpoint of reactivity.
Specific examples of amines include diaminodiphenylmethane, diaminodiphenylsulfone, 4,4′-diamino-3,3′-dimethyldiphenylmethane, diaminodiphenyl ether, diethylmethylbenzenediamine, 2-methyl-4,6-bis(methylthio )-1,3-benzenediamine, bisaniline, diethyltoluenediamine, aromatic amines such as diethylthiotoluenediamine, N,N'-bis(sec-butylamino)diphenylmethane, methylamine, dimethylamine, trimethylamine, ethylamine, Aliphatic amines such as diethylamine, triethylamine, ethylenediamine, tetramethylethylenediamine, hexamethylenediamine, norbornanediamine, polyetheramine, triethylenetetramine, and tetraethylenepentamine, and modified amines. Diethylmethylbenzenediamine, 4,4'-diamino-3,3'-dimethyldiphenylmethane, and diethyltoluenediamine are particularly preferred.
As hydrazides, organic acid hydrazide compounds are particularly preferably used. For example, the aromatic hydrazides salicylic acid hydrazide, terephthalic acid dihydrazide, isophthalic acid dihydrazide, 2,6-naphthoic acid dihydrazide, 2,6-pyridine dihydrazide, 1,2,4-benzenetrihydrazide, 1,4,5,8 - naphthoic acid tetrahydrazide, pyromellitic acid tetrahydrazide, and the like. Examples of aliphatic hydrazide compounds include formhydrazide, acetohydrazide, propionic hydrazide, oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, pimelic acid dihydrazide, sebacic acid dihydrazide, 1,4-cyclohexanedihydrazide, tartaric acid dihydrazide, malic acid dihydrazide, iminodiacetic acid dihydrazide, N,N'-hexamethylenebissemicarbazide, citric acid trihydrazide, nitriloacetic acid trihydrazide, cyclohexanetricarboxylic acid trihydrazide, 1,3-bis( a dihydrazide compound having a hydantoin skeleton such as hydrazinocarbonoethyl)-5-isopropylhydantoin, preferably a valine hydantoin skeleton (a skeleton in which a carbon atom of the hydantoin ring is substituted with an isopropyl group), tris(1-hydrazinocarbonylmethyl) isocyanurate, tris(2-hydrazinocarbonylethyl)isocyanurate, tris(1-hydrazinocarbonylethyl)isocyanurate, tris(3-hydrazinocarbonylpropyl)isocyanurate, bis(2-hydrazinocarbonylethyl)isocyanurate etc. can be given. From the balance between curing reactivity and latency, isophthalic acid dihydrazide, malonic acid dihydrazide, adipic acid dihydrazide, tris(hydrazinocarbonylmethyl)isocyanurate, tris(1-hydrazinocarbonylethyl)isocyanurate, tris(2- hydrazinocarbonylethyl)isocyanurate, tris(3-hydrazinocarbonylpropyl)isocyanurate, particularly preferably tris(2-hydrazinocarbonylethyl)isocyanurate.
Examples of imidazoles include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl- 2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6 (2'-methylimidazole (1') ) ethyl-s-triazine, 2,4-diamino-6 (2'-undecylimidazole (1')) ethyl-s-triazine, 2,4-diamino-6 (2'-ethyl, 4-methylimidazole ( 1′)) Ethyl-s-triazine, 2,4-diamino-6(2′-methylimidazole (1′))ethyl-s-triazine isocyanuric acid adduct, 2:3 addition of 2-methylimidazole isocyanuric acid 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyano Examples include various imidazoles of ethoxymethylimidazole, and salts of these imidazoles with polyvalent carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, maleic acid, and oxalic acid. be done.
Examples of thiols include Karenz MT PE1, BD1, NR1, trimethylolpropane tris (3-mercaptobutyrate), trimethylolethane tris (3-mercaptobutyrate) (all manufactured by Showa Denko K.K.), and the like. can be done. A thiol-based curing agent is a curing agent having at least one thiol group (SH) in its molecule.
Examples of phenols include phenol novolaks, bisphenol A, bisphenol S, and the like obtained by condensation reaction of phenol (which may have various substituents) with formalin in the presence of an acid catalyst.

When a thermosetting agent is used, a thermosetting accelerator may be used together. Examples of curing accelerators include phenols, organic acids, phosphines, imidazole, and the like.
Examples of the organic acid include organic carboxylic acid and organic phosphoric acid, and organic carboxylic acid is preferred. Specifically, aromatic carboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, benzophenonetetracarboxylic acid, furandicarboxylic acid, succinic acid, adipic acid, dodecanedioic acid, sebacic acid, thiodipropionic acid , cyclohexanedicarboxylic acid, tris(2-carboxymethyl)isocyanurate, tris(2-carboxyethyl)isocyanurate, tris(2-carboxypropyl)isocyanurate, bis(2-carboxyethyl)isocyanurate and the like. .
Examples of phosphines include triphenylphosphine and tetraphenylphosphonium tetraphenylborate.
Examples of imidazoles include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2 -methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6 (2'-methylimidazole (1')) Ethyl-s-triazine, 2,4-diamino-6(2'-undecylimidazole (1')) ethyl-s-triazine, 2,4-diamino-6(2'-ethyl-4-methylimidazole (1 ')) ethyl-s-triazine, 2,4-diamino-6(2'-methylimidazole (1'))ethyl-s-triazine isocyanuric acid adduct, 2:3 adduct of 2-methylimidazole isocyanuric acid , 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-3,5-dihydroxymethylimidazole, 2-phenyl-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxy and methylimidazole.

A radical polymerization initiator that can be used means a photoradical polymerization initiator and/or a thermal radical polymerization initiator. These can be used properly depending on the method of manufacturing the heat ray shielding structure, which is the heat ray absorbing film of the present invention.
The photoradical polymerization initiator that can be used is not particularly limited as long as it is a compound that generates radicals or acids by irradiation with ultraviolet rays or visible light and initiates a chain polymerization reaction. Cyclohexylphenyl ketone, diethylthioxanthone, benzophenone, 2-ethylanthraquinone, 2-hydroxy-2-methylpropiophenone, 2-methyl-[4-(methylthio)phenyl]-2-morpholino-1-propane, 2,4 ,6-trimethylbenzoyldiphenylphosphine oxide, camphorquinone, 9-fluorenone, diphenyldisulfide and the like. Specifically, IRGACURE ^RTM 651, 184, 2959, 127, 907, 369, 379EG, 819, 784, 754, 500, OXE01, OXE02, DAROCURE ^RTM 1173, LUCIRIN ^RTM TPO (all manufactured by BASF), Seikuol ^RTM Z, BZ, BEE, BIP, BBI (all manufactured by Seiko Kagaku Co., Ltd.) and the like.
Further, the molar extinction coefficient (ε) at 365 nm is preferably 50 or more and 10000 (mL/g cm) or less, more preferably 100 or more and 8000 (mL/g cm) or less, and 1000 or more and 7500 ( mL/g·cm) or less is particularly preferred. The molar extinction coefficient is measured using methanol or acetonitrile as a solvent.
Photopolymerization initiators having a molar extinction coefficient (ε) at 365 nm of 100 or more and 10000 (mL/g cm) or less include Omnirad ^RTM 651 (ε in methanol = 360 mL/g cm), Omnirad ^RTM 907 (in methanol ε=4700 mL/g cm), Omnirad ^RTM 369 (ε=7900 mL/g cm in methanol), Omnirad ^RTM 379 (ε=7900 mL/g cm in methanol), Omnirad ^RTM 819 (ε=2300 mL/g in methanol cm), Omnirad ^RTM TPO (ε in acetonitrile = 4700 mL/g cm), IRGACURE ^RTM OXE-01 (ε in acetonitrile = 7000 mL/g cm), IRGACURE ^RTM OXE-02 (ε in acetonitrile = 7700 mL/g cm). cm), etc., but is not limited to these.
When a radical photopolymerization initiator is used, its content is preferably 0.01 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total amount of the binder resin.
The preferred upper limit of this content is 7 parts by mass, more preferably 5 parts by mass, particularly preferably 4 parts by mass, and most preferably 3 parts by mass.
A preferred lower limit is 0.01 parts by mass, more preferably 0.1 parts by mass, particularly preferably 1 part by mass, and most preferably 1.5 parts by mass.

The thermal radical polymerization initiator that can be used is not particularly limited as long as the thermal radical polymerization initiator is a compound that generates radicals by heating and initiates a chain polymerization reaction, and organic peroxides, azo compounds, and benzoin compounds. , benzoin ether compounds, acetophenone compounds, benzopinacol, etc., and benzopinacol is preferably used. For example, organic peroxides include Kayamec (registered trademark) A, M, R, L, LH, SP-30C, Perkadox CH-50L, BC-FF, Kadox B-40ES, Perkadox 14, and Trigonox ^RTM 22. -70E, 23-C70, 121, 121-50E, 121-LS50E, 21-LS50E, 42, 42LS, Kayaester ^RTM P-70, TMPO-70, CND-C70, OO-50E, AN, Kayabutyl ^RTM B, Perkadox 16, Kayacarvone (registered trademark) BIC-75, AIC-75 (manufactured by Kayaku Akzo Co., Ltd.), Permec (registered trademark) N, H, S, F, D, G, Perhexa (registered trademark) H, HC , TMH, C, V, 22, MC, Percure (registered trademark) AH, AL, HB, Perbutyl (registered trademark) H, C, ND, L, Percumyl (registered trademark) H, D, Perloyl (registered trademark) IB , IPP, and Perocta (registered trademark) ND (manufactured by NOF Corporation) are commercially available. As azo compounds, VA-044, V-070, VPE-0201, VSP-1001 (manufactured by Wako Pure Chemical Industries, Ltd.) and the like are commercially available.
When a thermal radical polymerization initiator is used, its content is preferably 0.01 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total amount of the binder resin.
The preferred upper limit of this content is 7 parts by mass, more preferably 5 parts by mass, particularly preferably 4 parts by mass, and most preferably 3 parts by mass.
A preferred lower limit is 0.01 parts by mass, more preferably 0.1 parts by mass, particularly preferably 1 part by mass, and most preferably 1.5 parts by mass.
The most preferable range for the content in the resin composition is 1.5 parts by mass or more and 3 parts by mass or less.

<White ink>
A white ink can be produced using the above dispersion. The white ink will be described below.
The white ink according to this embodiment contains the above-described hollow particles according to this embodiment as a colorant. The white ink according to this embodiment can be used as an ink selected from the group consisting of water-based ink, latex ink, solvent ink, and ultraviolet curing ink. Such various inks can be prepared by appropriately adding components necessary for each ink together with hollow particles as a colorant.

[Latex ink]
When the white ink according to this embodiment is latex ink, the white ink preferably contains water, a water-soluble organic solvent, and a resin. The resin in the white ink can also be emulsified or suspended.
Examples of water and water-soluble organic solvents include those contained in water-based inks.

Examples of resins include water-soluble vinyl-based resins, acrylic-based resins, alkyd-based resins, polyester-based resins, phenoxy-based resins, polyolefin-based resins, and modified resins thereof. Among these, acrylic resins, water-soluble polyurethane resins, water-soluble polyester resins, water-soluble acrylic resins, and the like are preferable.

[Solvent ink]
When the white ink according to the present embodiment is a solvent ink, the white ink preferably contains a dispersant and a non-aqueous organic solvent.

Examples of the dispersant include Solbin series manufactured by Nissin Chemical Industry Co., Ltd.; Floren series manufactured by Kyoeisha Chemical Co., Ltd.; ANTI-TERRA series and DISPERBYK series manufactured by BYK Chemie Japan Co., Ltd.;

Examples of non-aqueous organic solvents include hydrocarbon-based, ester-based, and ketone-based solvents. Examples of hydrocarbon solvents include n-hexane, n-heptane, n-octane, isooctane, cyclohexane, methylcyclohexane, benzene, toluene, o-xylene, m-xylene, p-xylene and ethylbenzene. Ester-based solvents include propyl formate, n-butyl formate, isobutyl formate, amyl formate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, and n-n acetate. -amyl, isoamyl acetate, methyl isoamyl acetate, sec-hexyl acetate, methyl propionate, ethyl propionate, n-butyl propionate, butyl butyrate, ethyl butyrate, methyl lactate, γ-butyrolactone and the like. Ketone solvents include methyl ethyl ketone, methyl-n-propyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, diethyl ketone, ethyl-n-butyl ketone, di-n-propyl ketone, mesityl ketone and the like.

[UV curable ink]
When the white ink according to the present embodiment is ultraviolet curable ink, the white ink preferably contains a curable monomer or curable oligomer and a photocuring initiator. Also, the white ink may further contain a photocurable sensitizer.

As used herein, the term "curable monomer" means a monomer that is polymerized to form a cured product upon application of an external stimulus. The term "curable oligomer" means an oligomer that polymerizes and forms a cured resin when externally applied a stimulus.
Examples of curable monomers include radical polymerization type low-viscosity acrylic monomers; cationic polymerization type vinyl ethers, oxetane monomers, and cycloaliphatic epoxy monomers.
Examples of curable oligomers include cationic polymerization type acrylic oligomers.

Low-viscosity acrylic monomers include methoxypolyethylene glycol acrylate, phenoxyethylene glycol acrylate, phenoxydiethylene glycol acrylate, phenoxyhexaethylene glycol acrylate, methoxypolyethylene glycol methacrylate, 3-chloro-2-hydroxypropyl methacrylate, β-carboxyethyl acrylate, and acryloyl. morpholine, diacetone acrylamide, vinylformamide, N-pyrrolidone, neopentyl glycol dimethacrylate 2PO neopentyl glycol dimethacrylate, polyethylene glycol diacrylate, ethylene glycol dimethacrylate, polypropylene glycol diacrylate, tetraethylene glycol diacrylate, Glycerin dimethacrylate, glycerin acrylate methacrylate, modified epoxidized polyethylene glycol diacrylate, 2-(2-vinyloxyethoxy)ethyl acrylate, ethoxylated trimethylolpropane triacrylate, ethoxylated glycerin triacrylate, EO-modified trimethylolpropane triacrylate acrylates and the like.

Vinyl ethers include hydroxybutyl vinyl ether, triethylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, propenyl ether of propylene carbonate, dodecyl vinyl ether, cyclohexanedimethanol monovinyl ether, cyclohexane vinyl ether, diethylene glycol divinyl ether, 2-ethylhexyl vinyl ether, and dipropylene. Glycol divinyl ether, tripropylene glycol divinyl ether, hexanediol divinyl ether, octadecyl vinyl ether, butanediol divinyl ether, isopropyl vinyl ether, allyl vinyl ether, 1,4-butanediol divinyl ether, nonadiol divinyl ether, cyclohexanediol vinyl ether, cyclohexanedimethanol Vinyl ether, triethylene glycol divinyl ether, trimethylolpropane trivinyl ether, pentaerythritol tetravinyl ether, VEEA-2-(2-vinyloxyethoxy)ethyl acrylate, or VEEM-2-(2-vinyloxyethoxy)ethyl methacrylate, etc. is mentioned.

Examples of oxacene-based monomers include 3-ethyl-3-hydroxymethyloxetane, 1,4-bis[((3-ethyloxetan-3-yl)methoxy)methyl]benzene, 3-ethyl-3-[((3- ethyloxetan-3-yl)methoxy)methyl]oxetane, 3-ethyl-3-(phenoxymethyl)oxetane and the like.

Cycloaliphatic epoxy monomers include Celloxide 2000 and Celloxide 3000 (manufactured by Daicel Corporation); Dow Chemical Co.); DCPD-EP and its derivatives (Maruzen Petrochemical Co., Ltd.);

Examples of acrylic oligomers include hyperbranched polyester acrylates, polyester acrylates, urethane acrylates, epoxy acrylates, and the like.

The photopolymerization initiator is not particularly limited, and known photopolymerization initiators can be used depending on the purpose. Specific examples thereof include 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, Bis(2,6-dimethoxybenzoyl)-2,4,4-trimethyl-pentylphosphine oxide, 1-hydroxycyclohexylphenyl ketone (Irgacure 184; manufactured by BASF), 2-hydroxy-2-methyl-[4- (1-methylvinyl)phenyl]propanol oligomer (Esacure ONE; manufactured by Lamberti), 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1-propan-1-one ( Irgacure 2959; manufactured by BASF), 2-hydroxy-1-{4-[4-(2-hydroxy-2-methyl-propionyl)-benzyl]-phenyl}-2-methyl-propan-1-one (Irga Cure 127; manufactured by BASF), 2,2-dimethoxy-2-phenylacetophenone (Irgacure 651; manufactured by BASF), 2-hydroxy-2-methyl-1-phenyl-propan-1-one (Darocure 1173; manufactured by BASF company), 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one (Irgacure 907; manufactured by BASF), 2-benzyl-2-dimethylamino-1-(4 -morpholinophenyl)-butan-1-one, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, isopropylthioxanthone and the like.

Among them, from the viewpoint of curability and transparency, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 1-[4-(2-hydroxyethoxy)-phenyl]-2-hydroxy-2-methyl-1 -propan-1-one is preferred.

The photopolymerization initiator may also be an intramolecular hydrogen abstraction type photopolymerization initiator. As the intramolecular hydrogen abstraction type photopolymerization initiator, oxyphenyl acetic acid methyl ester (Irgacure MBF; manufactured by BASF), oxyphenyl acetic acid, 2-[2-oxo-2-phenylacetoxyethoxy] ethyl ester and oxy Oxyphenyl-based photopolymerization initiators such as a mixture with phenylacetic acid and 2-(2-hydroxy-ethoxy)ethyl ester (Irgacure 754; manufactured by BASF).

A photopolymerization initiation aid such as amines may be used in combination with the photopolymerization initiator. Examples of amines include 2-dimethylaminoethyl benzoate, dimethylaminoacetophenone, ethyl p-dimethylaminobenzoate, and isoamyl p-dimethylaminobenzoate.

[Preparation method etc.]
The white ink according to this embodiment can be prepared by adding hollow particles to a target liquid medium such as water or a non-aqueous solvent and dispersing the particles by a known method. Dispersion methods include, for example, a method in which a colorant and a dispersant are placed in a high-speed stirring homogenizer, sand mill (bead mill), roll mill, ball mill, paint shaker, ultrasonic disperser, microfluidizer, etc., and dispersed. . As an example, when a sand mill is used, beads having a particle diameter of about 0.01 mm to 1 mm can be used, and the filling rate of the beads can be appropriately set for dispersion treatment.

The dispersion thus obtained may be subjected to operations such as filtration and centrifugation. By this operation, the size of the particle diameter of the particles contained in the dispersion liquid can be uniformed.

All of the components described above may be used singly or in combination of two or more.
In addition, with respect to all of the above-mentioned matters and the like, a combination of preferable items is more preferable, and a combination of more preferable items is even more preferable. The same applies to combinations of preferable and more preferable items, combinations of more preferable and more preferable items, and the like.

<Cosmetics>
Cosmetics can be produced using the non-spherical hollow particles of the present invention. Cosmetics are described below.
For the non-spherical hollow particles, for example, esters, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, moisturizing agents, water-soluble polymers, thickeners, film-forming agents, and UV-absorbing agents agents, sequestering agents, lower alcohols, polyhydric alcohols, sugars, amino acids, organic amines, polymer emulsions, pH adjusters, skin nutrients, vitamins, antioxidants, antioxidant aids, fragrances, water, etc. It can be produced by a conventional method according to the desired dosage form.
Cosmetics using the non-spherical hollow particles of the present invention can be used in various applications for the purpose of controlling and/or coloring the color of skin and lips, and/or shielding against ultraviolet rays. The cosmetics may be solid cosmetics, liquid cosmetics, or powder cosmetics.
Examples of liquid cosmetics include lotions, milky lotions, gels, creams, beauty essences, sunscreen cosmetics, packs, masks, hand creams, body lotions, and basic cosmetics such as body creams; Cleansing (makeup remover), body shampoo, shampoo, rinse, and cleansing cosmetics such as treatments. Further, for example, a cosmetic composition that functions as both a basic cosmetic and a cleansing cosmetic, such as a so-called cleansing lotion that functions as both a lotion and cleansing agent, a cleansing milk, and a cleansing cream, may be used. Furthermore, the cosmetic composition of the present invention may be a rinse-off (rinse off) type or a leave-on (without rinsing off) type.
Solid powder cosmetics include, for example, loose powder cosmetics; solid powder cosmetics formed by compression molding or removing the solvent after being filled in a container; and pouring a paste into a container. paste-like cosmetics formed by; stick-type cosmetics; and the like. Specific examples include foundation, stick foundation, face powder, lipstick, blusher, eye color, eyebrow, makeup base, daytime serum, sunscreen, concealer, bronzer, lip color, BB cream, and the like.
As the product form of powder cosmetics, it is possible to take any product form within the category of powder cosmetics. Specifically, it can take product forms such as foundation, eye shadow, cheek color, body powder, perfume powder, baby powder, pressed powder, deodorant powder, face powder, and the like.

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples. It should be noted that the present invention is not limited to the following examples as long as the gist thereof is not exceeded.
In the Hollow Structure Particle Synthesis Example, when the desired amount of the substance could not be obtained by one synthesis operation, the synthesis operation was repeated until the desired amount of the substance was obtained.
A transmission electron microscope (JEM-2800 manufactured by JEOL Ltd.) was used to measure the major axis diameter, minor axis diameter, and inner diameter of the non-spherical particles when necessary.

[Synthesis Example 1-1: Preparation of Ethanol Dispersion of Ellipsoidal Organic Particles (Dispersion 1)]
27 g of styrene, 2 g of methacrylic acid and 0.1 g of potassium persulfate were added to 900 g of distilled water, and emulsion polymerization was carried out at 75° C. to obtain an aqueous dispersion containing styrene-methacrylic acid polymer particles (a). The major axis diameter of the obtained organic particles was 260 nm.
The aqueous dispersion obtained above was treated with a wet bead mill at a peripheral speed of 5 m/s for 10 minutes, so that the organic particles had a non-spherical shape and a major axis diameter of 440 nm. Dispersion 1 was prepared by adding ethanol while concentrating the obtained dispersion with an evaporator to replace water with ethanol. The content of organic particles in Dispersion 1 was 9%.

[Synthesis Example 1-2: Preparation of ethanol dispersion of ellipsoidal organic particles (dispersion 2)]
Dispersion 2 was prepared in the same manner as in Synthesis Example 1-1, except that 27 g of styrene used in Synthesis Example 1-1 was changed to 10 g. The major axis diameter of the obtained organic particles was 170 nm and 250 nm after wet bead milling. The content of organic particles in Dispersion 2 was 6%.

[Synthesis Example 1-3: Preparation of ethanol dispersion of ellipsoidal organic particles (dispersion 3)]
Dispersion 3 was prepared in the same manner as in Synthesis Example 1-1, except that the wet bead milling time was changed from 10 minutes to 1 minute. The major axis diameter of the organic particles in Dispersion 3 was 300 nm.

[Synthesis Example 1-4: Preparation of ethanol dispersion of ellipsoidal organic particles (dispersion 4)]
Dispersion 4 was prepared in the same manner as in Synthesis Example 1-1, except that the wet bead milling time in Synthesis Example 1-1 was changed from 10 minutes to 20 minutes. The major axis diameter of the organic particles in dispersion liquid 4 was 560 nm.

[Synthesis Example 1-5: Preparation of ethanol dispersion of spherical organic particles (dispersion 5)]
Dispersion 5 was prepared in the same manner as in Synthesis Example 1-1, except that the wet bead mill was not performed in Synthesis Example 1-1.
[Synthesis Example 1-6: Preparation of ethanol dispersion of ellipsoidal organic particles (dispersion 6)]
Dispersion 4 was prepared in the same manner as in Synthesis Example 1-1, except that the wet bead milling time was changed from 10 minutes to 45 minutes. The major axis diameter of the obtained ellipsoidal organic particles (A) was 680 nm.

[Production Example 1]
[Step 1]: Step of obtaining non-spherical core-shell particles 8 g of acetonitrile, 0.1 g of polyvinylpyrrolidone, and Dispersion 1 (17 g) were cooled to 10°C to obtain a liquid. To this liquid, 18 g of titanium tetrabutoxide and 6 g of 2% aqueous ammonia were added in 6 portions at intervals of 0.5 hours, and reacted at 10° C. for 4 hours to obtain a liquid containing non-spherical core-shell particles. rice field. The obtained liquid was used for the following "Step 2" without isolation/purification.

[Step 2]: Step of obtaining non-spherical core-shell particles To the liquid obtained in Step 1 of Production Example 1, 0.35 g of tetraethyl orthosilicate and 7 g of distilled water were added at 25°C and reacted at 25°C for 10 hours. I got the liquid.
The resulting liquid was centrifuged at 15,000 rpm for 25 minutes to remove the supernatant, and the residue was dried in a vacuum dryer heated to 60° C. to obtain 7.5 g of the desired non-spherical core-shell particles.

[Production Example 2]
[Step 1]: Step of obtaining non-spherical core-shell particles 12 g of ethanol, 8 g of acetonitrile, 0.1 g of polyvinylpyrrolidone, and Dispersion 2 (12 g) were cooled to 10°C to obtain a liquid. To this liquid, 9 g of titanium tetrabutoxide and 3 g of 2% aqueous ammonia were added in three portions at intervals of 0.5 hours, and reacted at 10° C. for 4 hours to obtain a liquid containing non-spherical core-shell particles. rice field. The obtained liquid was used for the following "Step 2" without isolation/purification.

[Step 2]: Step of obtaining non-spherical core-shell particles To the liquid obtained in Step 1 of Synthesis Example 2-2, 0.17 g of tetraethyl orthosilicate and 7 g of distilled water were added at 25°C and reacted at 25°C for 10 hours. and obtained a liquid.
The resulting liquid was centrifuged at 15,000 rpm for 25 minutes to remove the supernatant, and the residue was dried in a vacuum dryer heated to 60° C. to obtain 4 g of the desired non-spherical core-shell particles.

[Production Examples 3 and 4]
Non-spherical core-shell particles were obtained in the same manner as in Production Example 1, except that Dispersion 1 used in Production Example 1 was changed to Dispersion 3 and Dispersion 4, respectively. These are referred to as production examples 3 and 4, respectively.

[Production Example 5]
For Production Example 5, non-spherical core-shell particles were obtained in the same manner as in Production Example 2, except that the number of additions of titanium tetrabutoxide and 2% aqueous ammonia in Step 1 of Production Example 2 was changed from 3 times to 15 times.

[Production Examples 6 and 7]
Non-spherical core-shell particles were obtained in the same manner as in Production Example 1, except that Dispersion 1 used in Production Example 1 was changed to Dispersion 5 and Dispersion 6, respectively. Production Examples 6 and 7, respectively.

The major axis diameter (outer diameter) of the non-spherical core-shell particles obtained in Production Examples 1 to 7, the inner diameter of the core layer, their ratio (inner diameter E/outer diameter F), and the coefficient of variation content of the major axis diameter were measured as follows. Table 1 shows. As is clear from the coefficient of variation in Table 1, all the non-spherical core-shell particles of the present invention had a uniform major axis diameter.

[Example 1]: Step of firing non-spherical core-shell particles to remove organic particles and produce non-spherical hollow particles.
2.0 g of the non-spherical core-shell particles of Production Example 1 were placed on a ceramic board, set in a firing furnace, and fired at 1100° C. for 3 hours in an air atmosphere to produce 0 non-spherical hollow particles containing titanium oxide and silica. .9 g was obtained.

[Examples 2 to 5 and Comparative Examples 1 to 2]: Step of firing non-spherical core-shell particles to remove organic particles and produce non-spherical hollow particles.
For Production Examples 2 to 5 and Production Examples 6 and 7, except that the non-spherical core-shell particles of Production Example 1 used in Example 2 were changed to the non-spherical core-shell particles of Production Examples 2-5 and Production Examples 6 and 7, respectively. Non-spherical hollow particles were obtained in the same manner as in Example 1. Examples 2 to 5 and Comparative Examples 1 and 2 correspond to Production Examples 1 to 7, respectively.

[Surface treatment of non-spherical hollow particles]
The synthesized non-spherical hollow structure particles were dispersed in ion-exchanged water, heated, and then stearic acid was adsorbed to the hollow structure particles in an amount of 3% by mass, followed by washing and drying to obtain surface-treated hollow structure particles. .

Table 2 shows the aspect ratios (major axis diameter/minor axis diameter) of the non-spherical hollow particles of Examples 1 to 5 and Comparative Examples 1 and 2.

[Comparative particles]
Titanium oxide particles (CR-50-2, manufactured by Ishihara Sangyo Co., Ltd.) were used as comparative particles for the cosmetic composition.

[Powdery foundation]
A powdery foundation containing the obtained surface-treated hollow-structured particles was prepared at the compounding ratio shown in Table 3, and the evaluation when applied to the skin was evaluated by the following method.

[Method for producing powdery foundation]
Mix talc and color pigment in a blender. The rest of the powder is added to this and mixed well, then a binder and a preservative are added, and after toning, perfume is sprayed and mixed uniformly. After pulverizing this with a pulverizer, it is passed through a sieve and compression-molded into a medium plate.

[Evaluation method]
Concerning the concealability and spreadability, each cosmetic was used by panelists (10 persons), and sensory evaluation (score) was carried out on a scale of 5. Based on the score average value, evaluation was made according to the following evaluation criteria.
(Score)
5: Very good 4: Excellent 3: Normal 2: Poor 1: Very poor (evaluation criteria)
◎: Evaluation average value 4.0 or more and 5.0 or less ○: Evaluation average value 3.0 or more and less than 4.0 ×: Evaluation average value 1.0 or more and less than 3.0

[Reference example 1]
0.07 g of the non-spherical core-shell particles produced in Production Example 2 and 0.175 g of a dispersant (manufactured by BYK-Chemie Japan, DISPERBYK-2010) were added to 7 mL of distilled water, and added to Filmix (manufactured by Primix, RM). In addition, an aqueous dispersion of Reference Example 1 was prepared by treating for 10 minutes at a rotation speed of 10000 rpm.

[Examples 6 and 7]
Aqueous dispersions of Examples 6 and 7 were prepared in the same manner as in Reference Example 1 except that the non-spherical core-shell particles used in Reference Example 1 were changed to the spherical hollow particles of Examples 1 and 2, respectively.

[Comparative Example 4]
An aqueous dispersion of Comparative Example 3 was prepared in the same manner as in Reference Example 1 except that the non-spherical core-shell particles used in Reference Example 1 were changed to titanium oxide particles (manufactured by Ishihara Sangyo Co., Ltd., CR-50-2).

[Settling test]
The sedimentation properties (μm/s) of the white inks prepared in Examples 6 and 7, Reference Example 1, and Comparative Example 3 were measured using a centrifugal sedimentation dispersion stability analyzer (LUMiFuge 110, manufactured by Nippon Luft Co., Ltd.). did. The smaller the obtained value, the better the sedimentation property. The sedimentation test results are shown in Table 4 below.

As is clear from the results of hiding properties in Table 2, the cosmetics using non-spherical hollow particles had better hiding properties than the cosmetics of Comparative Examples using spherical hollow particles. In addition, as is clear from the results of sedimentation in Table 3, the aqueous dispersions of Examples 6 and 7 had improved sedimentation compared to the aqueous dispersion of Comparative Example 3, and storage stability was also improved. was excellent.

Since the non-spherical particles of the present invention are easier to produce than conventional ones and have a uniform major axis diameter, they can be used in various applications such as white pigments for inks, cosmetics, and light scattering aids.

Claims (11)

(A) contains titanium oxide,
Non-spherical hollow particles having a major axis diameter to minor axis diameter ratio of 1.1 to 10.0. 2. The non-spherical hollow particles according to claim 1, having a coefficient of variation (CV) of major axis diameter of 0.1 to 10%. 3. The non-spherical hollow particles according to claim 1, having a major axis diameter of 10 nm to 1000 nm. 4. The non-spherical hollow particles according to any one of claims 1 to 3, further comprising (B) silica. 5. The non-spherical hollow particles according to any one of claims 1 to 4, wherein (A) contains (A-1) rutile-type titanium oxide. The content of (A) titanium oxide is 86.0% by mass to 99.5% by mass or less, and the content of (B) silica is 0.5% by mass to 14.0% by mass, or 5. The non-spherical hollow particles according to 5. 7. E/F is 0.3 to 0.95, where E is the major axis diameter of the hollow particles and F is the major axis diameter of the non-spherical hollow particles. The non-spherical hollow particles according to . A cosmetic using the non-spherical hollow particles according to any one of claims 1 to 7. A dispersion containing (I) the non-spherical hollow particles according to any one of claims 1 to 7 and (II) a solvent. 10. The dispersion according to claim 9, further comprising (III) a dispersing agent. A white ink using the dispersion according to claim 9 or 10.

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