WO2009128441A1

WO2009128441A1 - Composite resin particles and use of the same

Info

Publication number: WO2009128441A1
Application number: PCT/JP2009/057491
Authority: WO
Inventors: 敏雄関谷
Original assignee: 綜研化学株式会社
Priority date: 2008-04-14
Filing date: 2009-04-14
Publication date: 2009-10-22
Also published as: KR20100134021A; JP5706687B2; JPWO2009128441A1; CN102007154B; KR101204963B1; CN102007154A

Abstract

Composite resin particles having a silicone resin core particle enclosed therein which are obtained by copolymerizing monomer components including an acrylic monomer and so on in the presence of silicone rein core particles having an average particle diameter ranging from 0.01 to 50 μm. A layer comprising these composite resin particles uniformly reflects an incident light.

Description

Composite resin particles and their uses

The present invention relates to a composite resin particle group containing silicone resin core particles and use thereof. More specifically, the present invention relates to a composite resin particle group formed using silicone resin core particles as seed particles and the use thereof.

The acrylic resin particles having an acrylic resin in the outer shell or the resin particles having polystyrene in the outer shell are used for various applications by utilizing the characteristics. Such resin particles are being widely used especially as optical members and cosmetic raw materials because the resin forming the outer shell is transparent.

There are various methods for manufacturing such resin particles. Core particles are manufactured, and the core particles are used as seed particles, and an outer shell made of acrylic resin or styrene resin is formed around the core particles. It can be produced by seed polymerization to form.

In general, when resin particles are produced by such seed polymerization, the outer shell-forming resin grows uniformly around the seed particles. Therefore, a uniform outer shell layer (shell) is formed around the seed particles around the seed particles. Layer) is formed. Silicone resin particles are used as seed particles used in such seed polymerization. For example, Patent Document 1 (Japanese Patent Laid-Open No. 7-96815), Patent Document 2 (Japanese Patent Laid-Open No. 2002-138119), etc. Describes resin particles covering the periphery of silicone resin particles.

However, the silicone fine particles described in Patent Document 1 are obtained by coating the periphery of silicone rubber sphere fine particles with a polyorganosilsesquioxane resin, and the silicone fine particles have rubber elasticity, However, the outer shell is made of a polyorganosilsesquioxane resin, so that it is not suitable as an optical material.

Patent Document 2 discloses that polymer particles in which a silicone compound represented by a specific formula or a partial hydrolysis condensate thereof is included in a polymer have a specific particle size distribution. The cited document 2 does not show in what form the obtained polymer particles include a silicone compound or a hydrolyzate thereof.

Patent Document 3 (Japanese Patent Application Laid-Open No. 2004-177426) includes a spherical core particle and a shell layer having a thickness of 100 ± 50 nm in its outer shell, and the refractive index of the core particle is higher than the refractive index of the core layer. High low reflection transparent spherical particles are disclosed. This particle forms a low-refractive index layer such as a fluorine-based polymer layer on the surface layer by two-stage polymerization by, for example, soap-free emulsion polymerization, and there is no description regarding the position of the core layer that forms this low-reflection transparent spherical particle For example, when the particles are produced by soap-free emulsion polymerization as shown in the example of Patent Document 3, the phenomenon that the core layer is unevenly distributed in the particles does not occur.

Patent Document 4 (Japanese Patent Laid-Open No. 2007-091515) discloses a silica particle having a spherical or substantially spherical outer shell having a hollow structure and an inner shell that is in contact with the outer shell and forms a convex portion toward the center. The invention is disclosed. In this Patent Document 4, a polymer is prepared by adding an acrylic monomer to a dispersion of colloidal silica to prepare a polymer, and then a polyalkoxysiloxane oligomer is added thereto to carry out a condensation reaction of the polyalkoxysiloxane oligomer. A silica component derived from the polyalkoxysiloxane oligomer is locally attached to the surface to prepare composite polymer particles, which are baked at a temperature of about 500 ° C. to remove the polymer component.

Therefore, the silica particles disclosed in Patent Document 4 are silica particles that are inorganic substances from which the polymer component has been removed by firing.

Japanese Laid-Open Patent Publication No.7-196815 JP 2002-138119 A JP 2004-177426 A JP 2007-091515 A

The object of the present invention is to provide a new composite resin particle group. Furthermore, the present invention provides an assembly of composite resin particles having a resin layer around the core material particles, and the core material particles present in each composite resin particle constituting the composite resin particle group are the composite resin particles. An object of the present invention is to provide a composite resin particle group containing a large number of unevenly distributed particles.

Furthermore, an object of the present invention is to provide a use of a composite resin particle group composed of composite resin particles in which core particles are unevenly distributed as described above, particularly a light diffusion sheet and a cosmetic.

In the composite resin particle group of the present invention, a monomer component containing an acrylic monomer and / or a styrene monomer is copolymerized in the presence of silicone resin core particles having an average particle diameter in the range of 0.01 to 50 μm. A composite resin particle group consisting of solid particles containing silicone resin core particles,
In the cross section of the composite resin particle cut so as to expose the substantially center of the silicone resin core material particle included in the composite resin particle constituting the composite resin particle group,
It passes through the center of the cross section of the silicone resin core material particle, passes through the virtual straight line (A) having the longest distance between the intersections with the outer peripheral surface of the composite resin particle, and the center of the cross section of the silicone resin core material particle. And when assuming a virtual straight line (B) with the shortest distance between the intersections with the outer peripheral surface of the composite resin particles,
The center point (P) of the silicone resin core particle is from the center point (P) of the silicone resin core particle to the point where the virtual straight line (A) or (B) is in contact with the surface of the composite resin particle. The shortest distance (R _mini ) and the longest distance (R) from the center point (P) of the silicone resin core particle to the point where the virtual line (A) or (B) contacts the surface of the composite resin particle 50% by number or more of composite resin particles in a position having a relationship represented by the following formulas (1) and (2) with respect to _max ).

In the above formulas (1) and (2), Dsi represents the diameter of the silicone resin core particle in the cross section, and is usually in the range of 0.01 to 50 μm, preferably in the range of 0.5 to 10 μm. It is in. The silicone resin core particle is a condensate of a silicone compound, but an alkoxide of titanium / zirconium may be blended in the silicone resin core particle.

The cosmetic of the present invention is characterized by being formed using the composite resin particle group as described above.
The light diffusion sheet of the present invention is characterized by being formed using the composite resin particle group as a reflective material.

The composite resin particles forming the composite resin particle group of the present invention have a shell layer obtained by seed polymerization of an acrylic resin or a styrene resin on a silicone particle core material, and the silicone resin core material forming the core layer includes The composite resin particles are not in the center and are unevenly distributed in either one of them.

When this composite resin particle is applied, the light reflection peak angle of each composite resin particle does not show a constant angle, but the reflection peel peels off due to the presence of a large number of particles. The variation in reflected light depending on the angle is reduced.

In the composite resin particle group of the present invention, the silicone resin core particles contained in each particle constituting the particle group are not present at the center of the composite resin particle but are present unevenly. For this reason, when the individual particles are viewed, the reflection peaks of the light do not coincide with each other. Therefore, the reflection peaks vary depending on the viewing angle. However, when such a composite resin particle group is applied to form a layer, the reflection peaks that are scattered among the particles cancel each other, and the dispersion of the reflection peaks depending on the viewing angle disappears.

Therefore, there is an effect that there is almost no variation in the light reflection peak due to the angle in the layer coated with the composite resin particles of the present invention.
By using the composite resin particle group as described above, the cosmetic of the present invention has a dull and clean finish.

Furthermore, the light diffusion sheet of the present invention can obtain a light diffusion sheet with very high uniformity by using the above-described composite resin particles with high reflection uniformity.

FIG. 1 is a perspective view having a notch portion showing an example of composite resin particles forming the composite resin particle group of the present invention. 2 is a cross-sectional view taken along the line XX in FIG. 3 is a cross-sectional view taken along the line YY in FIG. FIG. 4 is a cross-sectional view showing the center position of the silicone resin core material particles in the composite resin particles constituting the composite resin particle group of the present invention. FIG. 5 is a cross-sectional view showing an example of composite resin particles having a relatively high sphericity. FIG. 6 is a cross-sectional view showing another example of composite resin particles having a relatively high sphericity. FIG. 7 is a cross-sectional view showing an example of the composite resin of the present invention having a substantially elliptical cross section and a relatively low sphericity. FIG. 8 is a cross-sectional view showing an example of the composite resin particle of the present invention having a low sphericity. FIG. 9 is a cross-sectional view showing an example of composite resin particles having an irregular cross-section. FIG. 10 is an SEM photograph of the composite resin particle group of Example 1. FIG. 11 is an SEM photograph showing a cross section of the composite resin particle shown in FIG. 10 obtained in Example 1. FIG. 12 is an SEM photograph of the composite resin particle group obtained in Example 2. FIG. 13 is an SEM photograph showing a cross section of the composite resin particle shown in FIG. 12 obtained in Example 2. FIG. 14 is an SEM photograph of the composite resin particle group obtained in Example 3. FIG. 15 is an SEM photograph showing a cross section of the composite resin particle shown in FIG. 14 obtained in Example 3. FIG. 16 is an SEM photograph of the composite resin particle group obtained in Example 4. FIG. 17 is an SEM photograph showing a cross section of the composite resin particle shown in FIG. 16 obtained in Example 4. FIG. 18 is an SEM photograph of the composite resin particle group obtained in Example 5. FIG. 19 is an SEM photograph showing a cross section of the composite resin particle shown in FIG. 18 obtained in Example 5. FIG. 20 is an SEM photograph of the composite resin particle group obtained in Example 6. FIG. 21 is a SEM photograph showing a cross section of the composite resin particle shown in FIG. 20 obtained in Example 6. FIG. 22 is an SEM photograph of the composite resin particle group obtained in Example 7. FIG. 23 is a SEM photograph showing a cross section of the composite resin particle shown in FIG. 22 obtained in Example 7. FIG. 24 is a graph showing the rate of change in reflected light of the particle group obtained in Example 6. FIG. 25 is a graph showing the rate of change in reflected light of the particle group obtained in Comparative Example 3. FIG. 26 is a SEM photograph of the silicone resin core particles obtained in Production Example 3 used in Example 8. FIG. 27 is a SEM photograph of the composite resin particle group produced in Example 8. FIG. 28 is a graph showing the rate of change in reflected light of the particle group obtained in Example 8.

Hereinafter, the composite resin particle group of the present invention will be described with reference to the drawings.
FIG. 1 is a perspective view having a cutout portion showing an example of composite resin particles forming the composite resin particle group of the present invention, FIG. 2 is a sectional view taken along line XX in FIG. 1, and FIG. FIG.

The individual composite resin particles 10 constituting the composite resin particle group of the present invention are composed of a silicone resin core particle 30 and an acrylic resin layer (shell layer) 20 formed on the outer periphery of the silicone resin core particle 30. Is formed. In the present invention, the center P of the silicone resin core particle 30 that is the core material of the composite resin particle 10 and the center Q of the composite resin particle 10 do not coincide with each other. Is shifted to either one. In FIG. 1, the silicone resin core particles 30 are shifted to the right. This state is clearly shown in FIG. 3 showing the YY cross section of FIG. 1, and the center point Q of the composite resin particle 10 and the center point P of the silicone resin core particle do not coincide with each other. The center P of the silicone resin core particle 30 does not coincide with the Q of the composite resin particle 10. However, in this example, the silicone resin core particle 30 is not displaced in the vertical direction, and in FIG. 2 showing the XX cross section in FIG. 1, the center point P of the silicone resin core particle 30 and the composite resin particle 10 It coincides with the center point Q.

Such a shift of the silicone resin core particle 30 in the composite resin particle 10 can be expressed as follows.
In the cross section of the composite resin particle 10 cut so as to include at least a part of the silicone resin core particle 30, it passes through the center of the silicone resin core particle in this cross section, and the outer peripheral surface of the composite resin particle 10 in this cross section. And the virtual straight line (A) having the longest distance between the intersections with each other and the virtual straight line having the shortest distance between the intersections with the outer peripheral surface of the composite resin particles while passing through the center of the cross section of the silicone resin core particle 30 Virtualize (B).

And, the center point (P) of the silicone resin core particle is from the center point (P) of the silicone resin core particle to the point where the virtual straight line (A) or (B) is in contact with the surface of the composite resin particle. The shortest distance is R _mini and the longest distance from the center point (P) of the silicone resin core particle to the point where the virtual line (A) or (B) is in contact with the surface of the composite resin particle is R. When it is set to _max , R _mini and R _max are at positions having a relationship represented by the following expressions (1) and (2).

In the above formulas ((1), (1-1), (2), (2-1) to (2-3)), Dsi represents the diameter of the silicone resin core particles in the cross section.
In FIG. 2, R _mini and R _max are equal to R _mini and R _max because there is no vertical displacement of the composite resin particle 10 of the silicone resin core particle 30, but as shown in FIG. Since the material particles 30 are displaced in the lateral direction of the composite resin particles 10, R _mini and R _max show different values.

In the composite resin particle group of the present invention, the unevenly distributed particles in which the silicone resin core material particles 30 are ubiquitously present in the composite resin particles 10 as described above are at least 50 number /%, preferably 60 number /%. It is contained at a rate in the range of up to 100 pieces /%. When the silicone resin core material particles 30 are unevenly distributed in the composite resin particles 10 as described above, light incident on the individual particles is reflected in various directions depending on the uneven distribution state of the silicone resin core material particles 30. At first glance, it seems that the reflected light intensity becomes unstable due to the reflected light coming out in various directions, but the reflection peak is unexpectedly offset and the composite resin particle group of the present invention was applied. The light emitted from the layer is very stable with little fluctuation due to the viewing angle.

Furthermore, in the composite resin particle group of the present invention, the virtual straight line (C) is temporarily mounted radially outward from the center point Q with Q being the center point of any composite resin particle constituting the composite resin particle group. In this case, the center point P of the silicone resin core particles contained in the composite resin particles is present on the virtual straight line (C). As shown in FIG. 4, the center point Q of the composite resin particle, which is the base point of the virtual line (C), is set to 0%, and the length between the virtual line (C) and the outer peripheral surface of the composite resin particle is 100. %, The center point P of the silicone resin core particles contained in the composite resin particles is preferably in the position of more than 0% and 99% or less, and more preferably in the range of 10 to 95%. It is particularly preferred.

In the composite resin particle group of the present invention, the composite resin particles in which the silicone resin core particles are unevenly distributed as described above are 50 number /% or more of the entire composite resin particle group, and further 60 to 100 number. /% Is preferable.

The composite resin particles constituting the composite resin particle group of the present invention have an average particle diameter (φcp) in the range of 0.02 to 100 μm, preferably in the range of 1 to 20 μm. The average particle diameter (φsi) of the silicone resin core particles included in the composite resin particles is in the range of 0.01 to 50 μm, preferably in the range of 0.5 to 10 μm. As the average particle diameter of the silicone resin core particles at this time, the average particle diameter of the silicone resin core particles usually used for seed polymerization can be applied. It is preferable to obtain the average particle diameter (φcp) of the composite resin particles and the average particle diameter (φsi) of the silicone resin core particles from the SEM photograph of the cross section passing through the approximate center point Q of the composite resin particles.

When the composite resin particle is not substantially spherical, that is, when the cross-sectional shape is not substantially circular, the diameter of a virtual circle that can be drawn based on the arc of the composite resin particle that can be visually recognized in the SEM photograph is obtained. Average particle diameter (φcp).

In this case, as shown in FIG. 6, when both the virtual straight line A and the virtual straight line B pass through the center point Q of the composite resin particle and the center point P of the silicone resin core particle, The diameter of the resin particle and the diameter of the silicone resin particle can be obtained. However, as shown in FIG. 5, when either the center point Q or the center point P does not exist on the imaginary line, the center point Q and the center point It can be obtained by directly measuring the distance to P.

And in the composite resin particle group of the present invention, since the center point P of the silicone resin core material particle does not coincide with the center point Q of the composite resin particle and is unevenly distributed, the center point Q of the composite resin particle And a certain distance between the center point P of the silicone resin core particles. In FIG. 4, this distance is indicated by x. In the present invention, the average distance x between the center point Q of the composite resin particles and the center point P of the silicone resin core particles is usually in the range of 0.005 to 50 μm, preferably in the range of 0.1 to 20 μm. Is in.

In the present invention, the average distance x between the center point Q of the composite resin particles constituting the composite resin particle group and the center point P of the silicone resin core particles, and the average particle diameter (φcp of the composite resin particles )) (X / φcp) is usually in the range of 0.01 to 0.5, preferably in the range of 0.1 to 0.4. The ratio represented by (x / φcp) represents the degree of uneven distribution of the silicone resin core particles in the composite resin particle group, and as this value approaches 0, the silicone resin core material This means that the uneven distribution of particles is reduced.

When the composite resin particle group of the present invention is used for obtaining uniform reflected light such as an optical member or a cosmetic material, the ratio represented by (x / φcp) is set to 0.1 to 0.00. By setting it within the range of 35, it is possible to extract extremely uniform reflected light.

In this way, the composite resin particle group of the present invention having a large number of composite resin particles in which the silicone resin core particles are unevenly distributed cancels reflected light appropriately, so that when a layer coated with such a composite resin particle group is visually observed Variation in reflected light due to angle does not occur.

In addition, although said description demonstrated on the premise that the composite resin particle which comprises the composite resin particle group of this invention is a sphere, the particle | grains which comprise the composite resin particle group of this invention are not necessarily a sphere. For example, when the cross section is substantially elliptical as shown in FIG. 7, there are cases where the cross section is irregular as shown in FIGS. 8 and 9, but in these cases, the convex portions of these particles Assuming the sphere that contacts the most, the above definition is applied with the center point of the virtual sphere as the center point Q of the composite resin sphere.

The silicone resin core particles in the composite resin particles constituting such a composite resin particle group are usually covered with an acrylic resin and / or a styrene resin, but the composite resin forming the composite resin particle group The resin particles may contain composite resin particles in which, for example, 10 to 80% by volume of the silicone resin core particles are exposed on the surface of the particles.

The composite resin particles constituting the composite resin particle group of the present invention do not particularly need to be a perfect sphere as described above, and the composite resin particle group of the present invention is usually 0.1 to It is desirable to contain composite resin particles having a sphericity in the range of 1.00 in an amount of 50% by number or more.

FIGS. 5 and 6 show examples of composite resin particles having a relatively high sphericity. FIGS. 7 (substantially oval in cross section), FIGS. 8 and 9 show the composite of the present invention having a low sphericity. Although the example of the resin particle is shown, the shape of the composite resin particle which forms the composite resin particle group of this invention is not limited by these.

The specific characteristic of the composite resin particle group of the present invention is that 0.1 g of the composite resin particle group of the present invention is used, and this composite resin particle group is uniformly formed on a urethane sheet having a width of 30 mm, a length of 50 mm and a thickness of 3 mm It is clarified by forming a layer composed of a composite resin particle group by coating the layer and measuring the reflection intensity of the layer using a goniophotometer. That is, when the average variation rate of the reflection intensity measured on the layer formed as described above under the conditions of an incident angle of −45 ° and the number of trials n = 100 is usually in the range of 0.81 to 1.00. The value in is shown. Here, the fluctuation rate of the reflection intensity is a numerical value represented by an average value of reflectance at a light receiving angle of 0 ° / reflectance at a light receiving angle of −35 °, and the closer this value is to 1, 0, The smaller the unevenness and the smaller the width, the smaller the unevenness of reflection.

As described above, in the composite resin particle group of the present invention, the individual particles forming the particle group vary depending on the angle of the reflection peak because the position of the silicone resin core particle serving as the core material is different. In the composite resin particle group of the present invention, which is an aggregate of particles, variations due to the angle of the reflection peak as seen in individual particles cancel each other, and a layer having a very uniform reflection peak regardless of the angle is formed. Can be formed.

The composite resin particle group of the present invention is copolymerized with, for example, a silicone resin core material particle as a seed particle and a monomer component containing an acrylic monomer and / or a styrene monomer as a shell layer so that the seed particles are unevenly distributed. Can be manufactured.

The silicone resin core particles used in the present invention can be obtained by a known method using a silicon-containing compound such as a silane compound and a silane coupling agent.
Examples of the silane compound include those represented by the general formula (1) in Patent Document 2 (Japanese Patent Laid-Open No. 2002-138119).
(R ¹ O) _4-a SiR ² _a (1)
(Wherein R ¹ is the same or different, an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, or an acyl group having 1 to 10 carbon atoms, R ² is The same or different alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 10 carbon atoms or aralkyl group having 7 to 10 carbon atoms, a is an integer of 0 to 2) and / or a silicon compound thereof Specific examples of the partial hydrolysis condensate include tetramethyl silicate, methyltrimethoxysilane, methyltriethoxysilane, and phenyltriethoxysilane.

As the silane coupling agent, for example, the general formula (2)
X _3-n (CH ₃ ) _n Si (R ³ ) _n Y (2)
Wherein R ³ is a linear, branched or alicyclic alkyl group having 1 to 10 carbon atoms, X is an alkoxy group or a halogen atom, Y is an amino group, a vinyl group, (meth) acrylic. Group, isocyanate group, epoxy group, mercapto group, sulfur group, ureido group, n is an integer of 0 or 1)
Specific examples include 3-aminopropyltriethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, 3-methacrylate. Roxypropyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-octanoylthio Examples thereof include 1-propyltriethoxysilane and 3-ureidopropyltriethoxysilane.

Other silicon-containing compounds include reactive silicone (trade name: Silaplane) manufactured by Chisso Corporation.
The above silicon-containing compounds can be used alone or in combination of two or more compounds, but preferably a silane compound and a silane coupling agent are used in combination.

In the present invention, the silicone resin core particles may contain an alkoxide such as titanium alkoxide or zirconium alkoxide. These contents are usually 1 to 30 parts by weight with respect to 100 parts by weight of the silicone resin core particles.

In the present invention, the silicone resin core particle is a particle made of a hydrolyzate of a silicone compound reacted by a hydrolysis reaction. When a reactive double bond is present in the raw silicone compound, this reaction At least a part of the ionic double bond is present in the silicone resin core particle in a state where the activity is not lost. By leaving reactive double bonds in such silicone resin core particles, the silicone resin core particles in the present invention have a very high affinity with acrylic monomers or styrene monomers that form a shell layer. ing.

The slurry thus obtained is passed through, for example, a 200-mesh wire net to remove a lump, and then the reaction solution is separated by filtration under reduced pressure to obtain a silicone resin core particle cake. Silicone resin core particles can be obtained by heating and drying this cake to remove moisture and crush it.

When the average particle diameter is determined by observing the silicone resin core particles thus obtained with an SEM, the average particle diameter is in the range of 0.01 to 50 μm, preferably in the range of 0.5 to 20 μm. The CV value is usually in the range of 1 to 100, preferably 1 to 10.

Using the silicone resin core particles obtained as described above as seed particles, seed polymerization is performed to form a transparent resin layer (shell layer) containing acrylic resin and / or styrene resin on the outer periphery of the silicone resin core particles. To do. When forming this transparent resin layer, the transparent resin layer may be formed by one-stage polymerization, or the transparent resin layer may be formed by multi-stage polymerization such as two-stage polymerization.

Thus, the transparent resin layer formed on the outer periphery of the silicone resin core particle is formed of an acrylic resin, a styrene resin, or a transparent resin containing a copolymer resin thereof.
As acrylic resins used here, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth) acrylic acid Isobutyl, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, (meth) acrylic (Meth) acrylic acid alkyl ester having a hydrocarbon group having 1 to 20 carbon atoms which may have a branched or unsaturated bond such as dodecyl acid or lauryl (meth) acrylate;
(Meth) acrylic acid aryl esters such as benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenyl (meth) acrylate, phenoxydiethylene glycol (meth) acrylate;
(Meth) acrylic acid alkoxyalkyl esters such as methoxyethyl (meth) acrylate, ethoxyethyl (meth) acrylate, propoxyethyl (meth) acrylate, butoxyethyl (meth) acrylate, ethoxypropyl (meth) acrylate ;
Dialkylaminoalkyl (meth) acrylates such as diethylaminoethyl (meth) acrylate;
(Meth) acrylamides such as (meth) acrylamide, N-methylol (meth) acrylamide, diacetone acrylamide;
Epoxy group-containing (meth) acrylates such as glycidyl (meth) acrylate;
Acrylic acids such as (meth) acrylic acid;
(Meth) acrylic acid ester having a halogenated alkyl group such as (meth) acrylic acid-2-chloroethyl;
(Meth) acrylonitrile;
Derivatives of acrylic acid or methacrylic acid such as 2-hydroxyethyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate Can be mentioned. These can be used alone or in combination.

Examples of the styrene resin used in the present invention include styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, o-ethyl styrene, m-ethyl styrene, p-ethyl styrene, iso-propyl styrene, iso -Propyl styrene, iso-propyl styrene, pn-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-hexyl styrene, p-methoxy styrene, pn-nonyl styrene, pn-decyl styrene, 3,4- Examples thereof include a styrene derivative having an alkyl group substituted with a halogen atom, which may have a branch such as dichlorostyrene. These can be used alone or in combination.

Furthermore, the above-mentioned acrylic resin and styrene derivative can be used alone or in combination.
In producing the composite resin particle group of the present invention, in addition to the monomer components as described above, other polymerizable monomers can be blended.

Examples of such other monomers include vinyl acetate, vinyl propionate, vinyl n-butyrate, vinyl isobutyrate, vinyl pivalate, vinyl caproate, vinyl persamic acid, vinyl laurate, vinyl stearate, benzoic acid. Vinyl esters such as vinyl acid, pt-butyl vinyl benzoate and vinyl salicylate;
Vinylidene chloride, vinyl chlorohexanecarboxylate, etc .:
Unsaturated carboxylic acids such as tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, isocrotonic acid, norbornene dicarboxylic acid, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic acid;
And maleic anhydride, itaconic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, bicyclo [2,2,1] hept-2-ene-5,6-dicarboxylic anhydride and the like. These can be used appropriately within a range not impairing the identification of the composite resin particle group of the present invention. Furthermore, these monomers can be used alone or in combination.

Moreover, in order to form a crosslinked structure in the shell layer, a polyfunctional monomer can be used. Examples of such polyfunctional monomers include divinylbenzene, ethylene glycol di (meth) acrylate, diethyl glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene Di (meth) acrylates of alkylene glycols such as di (meth) acrylates of glycols, di (meth) acrylates of tripropylene glycolose;
Examples thereof include polyvalent (meth) acrylates such as trimethylolpropane tri (meth) acrylate. These can be used alone or in combination. Further, when the shell layer is formed in multiple stages, the polyfunctional monomer may be used at any stage. However, in order to increase the uneven distribution of the silicone resin core particles, the polyfunctional monomer is used in the first stage. However, it is desirable to use a polyfunctional monomer at a later stage, preferably the last stage.

In the composite resin particle group of the present invention, the above-mentioned silicone-based resin core particles are dispersed in an aqueous medium, and the above monomer is added to this dispersion to perform seed polymerization using the silicone-based resin core particles as seed particles. Can be manufactured. At this time, the monomer added to the aqueous medium in which the silicone resin core particles are dispersed is incorporated into the silicone resin particles and polymerized, and the diameter of the silicone resin core particles is 1 of the original particle diameter. .1-10 times. By polymerizing the monomer in this way, it is considered that the uneven distribution of the silicone resin core material particles occurs, and the monomer forming the shell layer in the present invention uses a monomer having a good affinity with the silicone resin core material particles. It is preferable. Since the core particles are thus formed of a silicone-based resin, it is extremely rare for the monomer to be uniformly incorporated into the silicone resin core particles, and the monomer concentration in the silicone resin core particles is uniform. In the composite resin particle group of the present invention, the uneven distribution of such a monomer is not centered in the composite resin particle of the present invention, and the center of the silicone resin core particle is not centered. It is considered that this is not the same as the center of the particles constituting the composite resin particle group to be obtained, and becomes a cause of uneven distribution of the core material particles.

In the present invention, as described above, the center of the silicone resin core material particles, which are seed particles, and the center of the individual particles constituting the composite resin particle group are not matched, and the silicone resin core material particles are unevenly distributed in the individual particles. Therefore, after the silicone resin core particles as seed particles are uniformly dispersed in an aqueous medium, preferably water, the above monomer components, and if necessary, a dispersant and a surfactant are blended while stirring, The monomer component is dispersed in the medium. After uniformly dispersing the silicone resin core particles and the monomer components as seed particles in the aqueous medium, the monomer component adsorbed on the silicone resin core particles is polymerized by adding a polymerization initiator and heating. Thus, the composite resin particle group of the present invention is obtained.

Further, by using the obtained composite resin particles as seed particles, the monomer component is adsorbed in the same manner as described above, and the monomer component is polymerized, whereby the particle diameter of the composite resin particles can be increased.

In the above reaction, the monomer component is 20 to 5000 parts by weight, preferably 200 to 3000 parts by weight based on 100 parts by weight of seed particles (silicone resin core particles or composite resin particles), and the aqueous medium is seed particles (silicone resin core material). Particles or composite resin particles) and the monomer component in a total amount of 100 parts by weight, 100 to 900 parts by weight, preferably 150 to 300 parts by weight. .1 to 10 parts by weight, preferably 0.2 to 3 parts by weight.

As the polymerization initiator used here, it is desirable to use a polymerization initiator having a 10-hour half-life temperature of usually 40 to 95 ° C., preferably 60 to 85 ° C. Examples of such polymerization initiator include: Cumene hydroperoxide (CHP), ditertiary butyl peroxide, dicumyl peroxide, benzoyl peroxide (BPO), lauryl peroxide (LPO), tertiary butyl (2-ethylhexanoyl) peroxide, dimethyl bis (tertiary) Butylperoxy) hexane, dimethylbis (tertiarybutylperoxy) hexyne-3, bis (tertiarybutylperoxyisopropyl) benzene, bis (tertiarybutylperoxy) trimethylcyclohexane, butyl-bis (tertiarybutylperoxy) ) Valerato, Gibe Examples of azo initiators include 2,2-azobisisobutyronitrile, 2,2-azobis-2-methylbutyronitrile 2,2-azobis-2. 2,2-dimethylvaleronitrile, 2,2-azobis-4-methoxy-2,4-dimethylvaleronitrile, 2,2-azobis (2-methylpropionic acid) dimethyl, and the like. These can be used alone or in combination.

The reaction temperature at this time varies depending on the type of polymerization initiator used, but is usually 50 to 80 ° C., preferably 60 to 75 ° C. Under these conditions, it is usually 2 to 10 hours, preferably 3 to By reacting for 6 hours, the composite resin particle group of the present invention is obtained. This reaction can be carried out in a single stage or in multiple stages.

In such a reaction, the monomer component infiltrates into the silicone resin core particles that are seed particles in a non-uniform manner and the polymerization reaction proceeds, so that the center of the silicone resin core particles exists at the center of the composite resin particles. 50% by number or more, preferably 60 to 100% by number of the individual composite resins constituting the composite resin particle group, and the center points of the silicone resin core particles as seed particles and the individual composite resin particles Does not match the center point.

As described above, the center point of the silicone resin core particle and the center point of each composite resin particle do not coincide with each other, and the refraction property of each particle is not uniform and is individual. When viewed, the refractive properties of the individual particles cancel each other, and when viewed as a whole of the composite resin particle group, very uniform reflected light can be obtained.

For example, 0.1 g of the composite resin particle group is uniformly applied to a urethane sheet having a width of 30 mm, a length of 50 mm, and a thickness of 3 mm, and the incident angle is −45 °, the number of trials is n, using a goniophotometer. = The variation rate of reflection intensity measured under the condition of 100 (the reflectance at the light receiving angle of 0 ° / the average value of the reflectance at the light receiving angle of -35 °) is usually in the range of 0.8 to 1.00 Of these, it is preferably in the range of 0.9 to 1.00, and reflected light with very high uniformity can be obtained. In FIG. 24, the composite particles of the present invention having an average particle diameter of 5 μm, in which the core particles are unevenly distributed, obtained by seed polymerization of styrene and methyl methacrylate on the silicone resin core particles are coated with a base material (trade name: The intensity of reflected light measured by applying to the surface of Bioskin # 30 (manufactured by Beaulux Co., Ltd.) and measuring a projection angle of 45 °, a measurement range of −85 ° to + 85 °, and a measurement interval of 1 ° is shown. The phenomenon that the reflection intensity becomes uniform as described above by using the composite resin particle group of the present invention cannot be predicted from the reflection intensity of the individual particles constituting the composite resin particle group. This is an effect that is exhibited only for the particle group.

The composite resin particle group of the present invention as described above has a characteristic that it can reflect a very uniform reflected light when it is layered as described above.
The composite resin particle group of the present invention as described above can be used as a cosmetic raw material. That is, the cosmetic of the present invention is a foundation using the above-mentioned composite resin particle group, or a cosmetic such as a liquid foundation, blusher, or mascara in which the composite resin particle group of the present invention is dispersed in a liquid. When using the composite resin particle group of this invention as a cosmetic raw material, the component normally used when manufacturing cosmetics can be used.

Since the cosmetic obtained in this way has high uniformity of light reflection, it has no dullness and has a clean finish. When the composite resin particle group of the present invention is used for such a cosmetic, the composite resin particle group of the present invention may be used together with other raw material components that are usually used when manufacturing the cosmetic. it can.

By utilizing this characteristic, a light diffusion sheet with very high uniformity can be produced.
That is, by forming the composite resin particle group layer in which the composite resin particle group is disposed on the substrate, the reflection of light in the composite resin particle group layer is made uniform, and the light can be diffused uniformly. In such a light diffusion sheet of the present invention, a light diffusion layer may be formed using the composite resin particle group of the present invention described in detail above.

Next, the composite resin particles of the present invention will be described with reference to examples, but the present invention is not limited thereto.
<Preparation of silicone resin core particles>
[Production Example 1]
200 parts by weight of ion-exchanged water and 5 parts by weight of isopropyl alcohol were charged into a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas introduction tube. While stirring this aqueous solution at 25 ° C., 25 parts by weight of methyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-13), 3-methacryloxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd.) , Trade name: KBM-503) When 5 parts by weight were added, the hydrolysis reaction proceeded, and the liquid temperature rose to 34 ° C. after 15 minutes.

Stirring is continued for 2 hours, the liquid temperature is cooled to 25 ° C., 5 parts by weight of 0.5% ammonia water is added with stirring, and the mixture is stirred for 1 minute, and then stirred for 4 hours. Thus, a slurry of silicone resin core particles was prepared.

The slurry was passed through a 200-mesh wire mesh and then filtered under reduced pressure using a filter paper with a Buchner funnel to obtain a cake of silicone resin core particles.
When the obtained silicone resin core material particles were observed with a scanning electron microscope (SEM), the particle shape was a true sphere, and the average particle size (φsi) was a monodisperse particle with 2.70 μm.

[Production Example 2]
In Production Example 1, the same conditions as in Production Example 1 were used, except that 28 parts by weight of methyltrimethoxysilane (KBM-13) and 2 parts by weight of 3-methacryloxypropyltrimethoxysilane (KBM-503) were used. A cake of silicone resin core particles was obtained.

When the obtained silicone resin core particle was observed with a scanning electron microscope (SEM), the particle shape was a true sphere, and the average particle size (φsi) was a monodisperse particle having a size of 2.6 μm.
[Production Example 3]
Into a glass flask having a capacity of 2 liters, 200 parts by weight of ion-exchanged water was added, 35 parts by weight of methyltrimethoxysilane (KBM-13) was added with stirring at 25 ° C., and the mixture was stirred for 1 hour.

Thereafter, 3.5 parts by weight of 0.4% aqueous ammonia was added and stirred for 1 minute, and then the stirring was stopped and left for 3 hours to obtain polyorganosiloxane particles. The obtained slurry was filtered through a 200-mesh wire mesh, and then filtered under reduced pressure using a filter paper with a Buchner funnel to obtain a polyorganosiloxane cake. This cake was a monodisperse molecule having an average particle diameter (φ _si ) of 2.5 μm.

[Example 1]
75 parts by weight of methyl methacrylate, 5 parts by weight of ethylene glycol dimethacrylate, 0.67 parts by weight of benzoyl peroxide, 0.5 parts by weight of sodium dodecylbenzenesulfonate, 0.1 parts by weight of sodium nitrite, and 200 parts by weight of ion-exchanged water Was stirred at 10000 rpm for 3 minutes using a homomixer (Special Machine Industries Co., Ltd., model: TK homomixer III, the same applies hereinafter).

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 20 parts by weight of the silicone resin core particles prepared in Production Example 1 and 40 parts by weight of ion-exchanged water were added. The mixture was added and reacted at 75 ° C. for 1 hour, followed by reaction at 90 ° C. for 2 hours.

Next, the aqueous dispersion obtained was filtered under reduced pressure using a filter paper with a Buchner funnel to give resin particle cake, and the obtained cake was dried using a hot air dryer set at 105 ° C. to obtain a composite resin particle group (I) was obtained.

About the obtained composite resin particle group (I), the average particle diameter (φcp) of the composite resin particles in the same manner as described above, the center of the composite resin particles constituting the composite resin particle group, and the center of the silicone resin core material particles Distance (x), ratio (x / φcp), variation rate, and sphericity were measured, and the results are shown in Table 1.

Moreover, the SEM photograph of the obtained composite resin particle group (I) is shown in FIG.
With respect to the composite resin particles constituting the composite resin particle group (I) thus obtained, a microtome is used so that the cross section of the silicone resin core particles that are impregnated with epoxy resin and become the core material of the composite resin particles is exposed. A cross section was cut out. This sectional view is shown in FIG.

As shown in FIG. 11, the diameter (Dsi) of the silicone resin particles is 2.54 μm, and the shortest is the point through the center point (P) of the silicone resin particles to the surface of the composite resin particles. A virtual straight line (B) is drawn, and the shortest (R _mini ) from the center point (P) of the silicone resin particle in this cross section to the point where the virtual straight line (B) contacts the surface of the composite resin particle is 1. It was 69 μm.

Further, when the virtual straight line (A) passing through the center of the cross section of the silicone resin core particle and having the longest distance between the intersection points with the outer peripheral surface of the composite resin particle is drawn, Consistent with B). In the virtual straight line (B), the longest distance (Rmax) from the center point (P) of the silicone resin core particle in this cross section to the point where the virtual straight line (B) contacts the surface of the composite resin particle is 2 .81 μm.

From these values, the composite resin particles satisfy the following formulas (1) and (2).

Similarly, for the composite resin particles constituting the composite resin particle group (I), the cross section was cut out and the position of the silicone resin core particles was measured as described above. As a result, at least the composite resin particle group (I) was measured. In 95% by number of the particles, the uneven distribution of the silicone resin core particles was observed.

[Example 2]
In Example 1, except that it was changed to 88.33 parts by weight of methyl methacrylate and 6.67 parts by weight of the silicone resin core particles prepared in Production Example 1, it was prepared under the same conditions as in Example 1, and the composite resin particle group ( II) was obtained.

About the obtained composite resin particle group (II), the average particle diameter (φcp) of the composite resin particles, the center of the composite resin particles constituting the composite resin particle group (II), and the silicone resin core particles in the same manner as described above The distance (x), the ratio (x / φcp), the variation rate, and the sphericity of the center of the sample were measured, and the results are shown in Table 1.

Moreover, the SEM photograph of the obtained composite resin particle group (II) is shown in FIG.
With respect to the composite resin particles constituting the composite resin particle group (II) thus obtained, a cross section was cut out so that a cross section of the silicone resin core material particles serving as the core material of the composite resin particles was exposed. This sectional view is shown in FIG. As shown in FIG. 13, the diameter (Dsi) of the silicone resin particles is 2.83 μm, and the shortest is the point through the center point (P) of the silicone resin particles to the surface of the composite resin particles. A virtual straight line (B) is drawn, and the shortest (R _mini ) from the center point (P) of the silicone resin particle in this cross section to the point where the virtual straight line (B) contacts the surface of the composite resin particle is 1. It was 46 μm.

Further, when the virtual straight line (A) passing through the center of the cross section of the silicone resin core particle and having the longest distance between the intersection points with the outer peripheral surface of the composite resin particle is drawn, Consistent with B). In this virtual straight line (B), the longest distance (R _max ) from the center point (P) of the silicone resin core particle in this cross section to the point where this virtual straight line (B) contacts the surface of the composite resin particle is: It was 4.86 μm.

Similarly, for the composite resin particles constituting the composite resin particle group (II), the cross section was cut out and the position of the silicone resin core particles was measured as described above. As a result, at least the composite resin particle group (I) was measured. In 98% by number of particles, uneven distribution of the silicone resin core particles was observed.

Example 3
<First stage polymerization>
Using the apparatus used in Example 1, 66.6 parts by weight of methyl methacrylate, 0.014 parts by weight of ethylene glycol dimethacrylate, 0.5 parts by weight of benzoyl peroxide, 0.5 parts by weight of sodium dodecylbenzenesulfonate, nitric acid 0.1 part by weight of sodium and 200 parts by weight of ion-exchanged water were stirred at 10,000 rpm for 3 minutes using a homomixer.

Subsequently, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 33.3 parts by weight of the silicone resin particles prepared in Production Example 2 and 40 parts by weight of ion-exchanged water were added. And gently stirred at 50 ° C. for 30 minutes.

Thereafter, 40 parts by weight of a PVA 5% aqueous solution was added and reacted at 75 ° C. for 1 hour, and then reacted at 90 ° C. for 1 hour to obtain a dispersion (III-1) of composite resin particle groups.
When the composite resin particles contained in the dispersion (III-1) of this composite resin particle group were observed by SEM, these composite resin particles were true spherical monodisperse particles having an average particle diameter of 4.13 μm. It was.

<Second stage polymerization>
Furthermore, using the same apparatus, methyl methacrylate 90 parts by weight, ethylene glycol dimethacrylate 5 parts by weight, benzoyl peroxide 1.0 part by weight, sodium dodecylbenzenesulfonate 0.5 part by weight, sodium nitrite 0.1 part by weight And 200 parts by weight of ion-exchanged water were stirred at 10,000 rpm for 3 minutes using a homomixer.

Subsequently, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 19.2 parts by weight of the dispersion (III-1) of the composite resin particle group was added, The mixture was reacted at 75 ° C. for 1 hour and subsequently reacted at 90 ° C. for 2 hours to obtain a dispersion of composite resin particle group (III-2).

The aqueous dispersion thus obtained was filtered under reduced pressure using a filter paper with a Buchner funnel to obtain a resin particle cake. The obtained cake was dried using a hot air dryer set at 105 ° C. to obtain a composite resin particle group ( III-2) was obtained.

With respect to the obtained composite resin particle group (III-2), the average particle diameter (φcp) of the composite resin particles, the center of the composite resin particles constituting the composite resin particle group, and the silicone resin core material particles in the same manner as described above The distance (x) from the center, the ratio (x / φcp), the variation rate, and the sphericity were measured, and the results are shown in Table 1.

An SEM photograph of the obtained composite resin particle group (III-2) is shown in FIG.
With respect to the composite resin particles constituting the composite resin particle group (III-2) thus obtained, the cross section was cut out so that the cross section of the silicone resin core material particles serving as the core material of the composite resin particles was exposed. This sectional view is shown in FIG. As shown in FIG. 15, the diameter (Dsi) of the silicone resin particles is 2.76 μm, and the shortest distance is from the center point (P) of the silicone resin particles to the point of contact with the surface of the composite resin particles. The virtual straight line (B) is drawn, and the shortest (R _mini ) from the center point (P) of the silicone resin particle in this cross section to the point where the virtual straight line (B) contacts the surface of the composite resin particle is 1. It was 50 μm.

Further, when the virtual straight line (A) passing through the center of the cross section of the silicone resin core particle and having the longest distance between the intersection points with the outer peripheral surface of the composite resin particle is drawn, Consistent with B). In this virtual straight line (B), the longest distance (R _max ) from the center point (P) of the silicone resin core particle in this cross section to the point where this virtual straight line (B) contacts the surface of the composite resin particle is: 7.24 μm.

Similarly, the cross section of the composite resin particles constituting the composite resin particle group (III-2) was cut out and the position of the silicone resin core particles was measured as described above. The composite resin particle group (III- In at least 95% by number of the particles of 2), uneven distribution of the silicone resin core particles was observed.

Example 4
<First stage polymerization>
Using the apparatus used in Example 1, 93.35 parts by weight of methyl methacrylate, 0.0185 parts by weight of ethylene glycol dimethacrylate, 1.0 part by weight of benzoyl peroxide, 0.5 parts by weight of sodium dodecylbenzenesulfonate, nitric acid 0.1 part by weight of sodium and 200 parts by weight of ion-exchanged water were stirred at 10,000 rpm for 3 minutes using a homomixer.

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 6.65 parts by weight of the silicone resin particles prepared in Production Example 1 and 40 parts by weight of ion-exchanged water were added. And gently stirred at 50 ° C. for 30 minutes.

Thereafter, 40 parts by weight of a PVA 5% aqueous solution was added, reacted at 75 ° C. for 1 hour, and then reacted at 90 ° C. for 1 hour to obtain a composite resin particle group dispersion (IV-1).
When the composite resin particles contained in the dispersion (IV-1) of this composite resin particle group were observed by SEM, these composite resin particles were true spherical monodisperse particles having an average particle diameter of 6.67 μm. It was.

<Second stage polymerization>
Further, using the same apparatus, 75 parts by weight of styrene, 5 parts by weight of divinylbenzene (manufactured by Nippon Steel Chemical Co., Ltd., product number: DVB-960, the same shall apply hereinafter), 2.0 parts by weight of benzoyl peroxide, dodecylbenzene 0.5 part by weight of sodium sulfonate, 0.1 part by weight of sodium nitrite and 200 parts by weight of ion-exchanged water were stirred at 10,000 rpm for 3 minutes using a homomixer.

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 76.2 parts by weight of the dispersion liquid (IV-1) of the composite resin particle group was added. The mixture was reacted at 75 ° C. for 3 hours, and subsequently reacted at 90 ° C. for 3 hours to obtain a dispersion of composite resin particle group (IV-2).

The aqueous dispersion thus obtained was filtered under reduced pressure using a filter paper with a Buchner funnel to obtain a resin particle cake. The obtained cake was dried using a hot air dryer set at 105 ° C. to obtain a composite resin particle group ( IV-2) was obtained.

With respect to the obtained composite resin particle group (IV-2), the average particle diameter (φcp) of the composite resin particles, the center of the composite resin particles constituting the composite resin particle group, and the silicone resin core particles in the same manner as described above The distance (x) from the center, the ratio (x / φcp), the variation rate, and the sphericity were measured, and the results are shown in Table 1.

An SEM photograph of the obtained composite resin particle group (IV-2) is shown in FIG.
With respect to the composite resin particles constituting the composite resin particle group (IV-2) thus obtained, the cross section was cut out so that the cross section of the silicone resin core material particles serving as the core material of the composite resin particles was exposed. This sectional view is shown in FIG. As shown in FIG. 17, the diameter (Dsi) of the silicone resin particles is 2.25 μm, and the shortest distance is from the center point (P) of the silicone resin particles to the point of contact with the surface of the composite resin particles. The virtual straight line (B) is drawn, and the shortest (R _mini ) from the center point (P) of the silicone resin particle in this cross section to the point where the virtual straight line (B) contacts the surface of the composite resin particle is 1. It was 51 μm.

Further, an imaginary straight line (A) that passes through the center of the cross section of the silicone resin core particle and has the longest distance between the intersection points with the outer peripheral surface of the composite resin particle is drawn, and the center of the silicone resin core particle in this cross section is drawn The longest distance (R _max ) from the point (P) to the point where the virtual straight line (A) is in contact with the surface of the composite resin particles was 9.81 μm.

Similarly, the cross section of the composite resin particles constituting the composite resin particle group (IV-2) was cut out and the positions of the silicone resin core particles were measured as described above. The composite resin particle group (IV- In at least 95% by number of the particles of 2), uneven distribution of the silicone resin core particles was observed.

Example 5
<First stage polymerization>
Using the apparatus used in Example 1, 66.7 parts by weight of methyl methacrylate, 0.0078 parts by weight of ethylene glycol dimethacrylate, 1.0 part by weight of benzoyl peroxide, 0.5 parts by weight of sodium dodecylbenzenesulfonate, nitric acid 0.1 part by weight of sodium and 200 parts by weight of ion-exchanged water were stirred at 10,000 rpm for 3 minutes using a homomixer.

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 33.3 parts by weight of the silicone resin particles prepared in Production Example 1 and 40 parts by weight of ion-exchanged water were added. And gently stirred at 50 ° C. for 30 minutes.

Thereafter, 40 parts by weight of a PVA 5% aqueous solution was added, reacted at 75 ° C. for 1 hour, and then reacted at 90 ° C. for 1 hour to obtain a dispersion (V-1) of composite resin particle groups.
When the composite resin particles contained in the dispersion (V-1) of this composite resin particle group were observed by SEM, these composite resin particles were true spherical monodisperse particles having an average particle diameter of 3.89 μm. It was.

<Second stage polymerization>
Further, using the same apparatus, 70 parts by weight of styrene, 10 parts by weight of divinylbenzene, 2.0 parts by weight of benzoyl peroxide, 0.5 parts by weight of sodium dodecylbenzenesulfonate, 0.1 part by weight of sodium nitrite and ions 200 parts by weight of exchange water was stirred for 3 minutes at 10,000 rpm using a homomixer.

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 76.2 parts by weight of the dispersion liquid (V-1) of the composite resin particle group was added. The mixture was reacted at 75 ° C. for 3 hours, and subsequently reacted at 90 ° C. for 3 hours to obtain a dispersion of composite resin particle group (V-2).

The aqueous dispersion thus obtained was filtered under reduced pressure using a filter paper with a Buchner funnel to obtain a resin particle cake. The obtained cake was dried using a hot air dryer set at 105 ° C. to obtain a composite resin particle group ( V-2) was obtained.

With respect to the obtained composite resin particle group (V-2), the average particle diameter (φcp) of the composite resin particles, the center of the composite resin particles constituting the composite resin particle group, and the silicone resin core particles in the same manner as described above The distance (x) from the center, the ratio (x / φcp), the variation rate, and the sphericity were measured, and the results are shown in Table 1.

An SEM photograph of the obtained composite resin particle group (V-2) is shown in FIG.
With respect to the composite resin particles constituting the composite resin particle group (V-2) thus obtained, the cross section was cut out so that the cross section of the silicone resin core material particles serving as the core material of the composite resin particles was exposed. This sectional view is shown in FIG. As shown in FIG. 19, the diameter (Dsi) of the silicone resin particles is 2.45 μm, and the shortest is the point through the center point (P) of the silicone resin particles to the surface of the composite resin particles. The virtual straight line (B) is drawn, and the shortest (R _mini ) from the center point (P) of the silicone resin particle in this cross section to the point where the virtual straight line (B) contacts the surface of the composite resin particle is 1. It was 23 μm.

Further, an imaginary straight line (A) that passes through the center of the cross section of the silicone resin core particle and has the longest distance between the intersection points with the outer peripheral surface of the composite resin particle is drawn, and the center of the silicone resin core particle in this cross section is drawn The longest distance (R _max ) from the point (P) to the point where the virtual straight line (A) is in contact with the surface of the composite resin particle was 3.92 μm.

Similarly, the cross section of the composite resin particles constituting the composite resin particle group (V-2) was cut out and the positions of the silicone resin core particles were measured as described above. As a result, this composite resin particle group (V- In at least 95% by number of the particles of 2), uneven distribution of the silicone resin core particles was observed.

Example 6
<First stage polymerization>
Using the apparatus used in Example 1, 93.3 parts by weight of methyl methacrylate, 0.02 part by weight of ethylene glycol dimethacrylate, 1.0 part by weight of benzoyl peroxide, 0.5 part by weight of sodium dodecylbenzenesulfonate, nitric acid 0.1 parts by weight of sodium and 200 parts by weight of ion-exchanged water were stirred at 10,000 rpm for 3 minutes using a homomixer.

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 6.7 parts by weight of the silicone resin particles prepared in Production Example 1 and 40 parts by weight of ion-exchanged water were added. And gently stirred at 50 ° C. for 30 minutes.

Thereafter, 40 parts by weight of a PVA 5% aqueous solution was added, reacted at 75 ° C. for 1 hour, and then reacted at 90 ° C. for 1 hour to obtain a composite resin particle group dispersion (VI-1).
When the composite resin particles contained in the dispersion liquid (VI-1) of this composite resin particle group were observed by SEM, the composite resin particles were true spherical monodisperse particles having an average particle diameter of 6.50 μm. It was.

<Second stage polymerization>
Further, using the same apparatus, 85 parts by weight of styrene, 5 parts by weight of divinylbenzene, 2.0 parts by weight of benzoyl peroxide, 0.5 parts by weight of sodium dodecylbenzenesulfonate, 0.1 part by weight of sodium nitrite and ions 200 parts by weight of exchange water was stirred for 3 minutes at 10,000 rpm using a homomixer.

Subsequently, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas introduction tube, and 37.7 parts by weight of the dispersion liquid (VI-1) of the composite resin particle group was added. The mixture was reacted at 75 ° C. for 3 hours and then reacted at 90 ° C. for 3 hours to obtain a dispersion of composite resin particle group (VI-2).

The aqueous dispersion thus obtained was filtered under reduced pressure using a filter paper with a Buchner funnel to obtain a resin particle cake. The obtained cake was dried using a hot air dryer set at 105 ° C. to obtain a composite resin particle group ( VI-2) was obtained.

With respect to the obtained composite resin particle group (VI-2), the average particle diameter (φcp) of the composite resin particles, the center of the composite resin particles constituting the composite resin particle group, and the silicone resin core material particles in the same manner as described above The distance (x) from the center, the ratio (x / φcp), the variation rate, and the sphericity were measured, and the results are shown in Table 1.

An SEM photograph of the obtained composite resin particle group (VI-2) is shown in FIG.
With respect to the composite resin particles constituting the composite resin particle group (VI-2) thus obtained, the cross section was cut out so that the cross section of the silicone resin core material particles serving as the core material of the composite resin particles was exposed. This sectional view is shown in FIG.

As shown in FIG. 21, the diameter (Dsi) of the silicone resin particles is 2.50 μm, and the shortest distance is from the center point (P) of the silicone resin particles to the point of contact with the surface of the composite resin particles. A virtual straight line (B) is drawn, and the shortest (R _mini ) from the center point (P) of the silicone resin particle in this cross section to the point where the virtual straight line (B) contacts the surface of the composite resin particle is 2. It was 69 μm.

Further, an imaginary straight line (A) that passes through the center of the cross section of the silicone resin core particle and has the longest distance between the intersection points with the outer peripheral surface of the composite resin particle is drawn, and the center of the silicone resin core particle in this cross section is drawn The longest distance (R _max ) from the point (P) to the point where the virtual straight line (A) is in contact with the surface of the composite resin particle was 9.04 μm.

The change rate of the reflection intensity of the particle group obtained here is shown in FIG.
Example 7
<First stage polymerization>
Using the apparatus used in Example 1, 66.7 parts by weight of methyl methacrylate, 0.013 parts by weight of ethylene glycol dimethacrylate, 1.0 part by weight of benzoyl peroxide, 0.05 part by weight of sodium dodecylbenzenesulfonate, nitric acid 0.01 parts by weight of sodium and 200 parts by weight of ion-exchanged water were stirred at 10,000 rpm for 3 minutes using a homomixer.

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 33.6 parts by weight of the silicone resin particles prepared in Production Example 1 and 40 parts by weight of ion-exchanged water were added. And gently stirred at 50 ° C. for 30 minutes.

Thereafter, 40 parts by weight of a PVA 5% aqueous solution was added, reacted at 75 ° C. for 1 hour, and then reacted at 90 ° C. for 1 hour to obtain a composite resin particle group dispersion (VII-1).
When the composite resin particles contained in the dispersion liquid (VII-1) of this composite resin particle group were observed by SEM, these composite resin particles were true spherical monodisperse particles having an average particle diameter of 4.63 μm. It was.

<Second stage polymerization>
Further, using the same apparatus, 75 parts by weight of styrene, 5 parts by weight of divinylbenzene, 2.0 parts by weight of benzoyl peroxide, 0.5 parts by weight of sodium dodecylbenzenesulfonate, 0.1 part by weight of sodium nitrite and ions 200 parts by weight of the exchange water was stirred at 10,000 rpm for 3 minutes using a homomixer.

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas introduction tube, and 76.9 parts by weight of the dispersion (V-1) of the composite resin particle group was added. The mixture was reacted at 75 ° C. for 3 hours, and subsequently reacted at 90 ° C. for 3 hours to obtain a dispersion of composite resin particle group (V-2).

An SEM photograph of the obtained composite resin particle group (V-2) is shown in FIG.
With respect to the composite resin particles constituting the composite resin particle group (V-2) thus obtained, the cross section was cut out so that the cross section of the silicone resin core material particles serving as the core material of the composite resin particles was exposed. This sectional view is shown in FIG. As shown in FIG. 23, the diameter (Dsi) of the silicone resin particles is 2.63 μm, and the shortest is the point through the center point (P) of the silicone resin particles to the surface of the composite resin particles. The virtual straight line (B) is drawn, and the shortest (R _mini ) from the center point (P) of the silicone resin particle in this cross section to the point where the virtual straight line (B) contacts the surface of the composite resin particle is 1. It was 38 μm.

Further, an imaginary straight line (A) that passes through the center of the cross section of the silicone resin core particle and has the longest distance between the intersection points with the outer peripheral surface of the composite resin particle is drawn, and the center of the silicone resin core particle in this cross section is drawn The longest distance (R _max ) from the point (P) to the point where the virtual straight line (A) is in contact with the surface of the composite resin particles was 4.06 μm.

Similarly, the cross section of the composite resin particles constituting the composite resin particle group (V-2) was cut out and the positions of the silicone resin core particles were measured as described above. As a result, the composite resin particle group (V- In at least 95% by number of the particles of 2), uneven distribution of the silicone resin core particles was observed.

Method for measuring sphericity The sphericity was determined by the following method.
The composite resin particle group is photographed using an electron microscope, and the obtained image is measured for circularity using image analysis software (Mitani Corporation, WinROOF). About 50 measurement values are averaged, and this is defined as sphericity. The circularity is calculated by the following formula.
Circularity = 4π × area / (perimeter length × perimeter length)
Example 8
40 parts by weight of MMA, 10 parts by weight of EGDMA, 1 part by weight of benzoyl peroxide, 0.3 part by weight of sodium lauryl sulfate, 300 parts by weight of ion-exchanged water, and 0.1 part by weight of sodium nitrite are mixed at 10000 rpm with a homomixer. Stir for minutes.

Next, this mixture was transferred to a 1-liter four-necked flask equipped with a thermometer and a nitrogen gas inlet tube, and 50 parts by weight of the polyorganosiloxane particles prepared in Production Example 3 were added, followed by stirring at 40 ° C. for 30 minutes. .

Thereafter, 2 parts by weight of polyvinyl alcohol was added and reacted at 69 ° C. for 1 hour and 30 minutes, followed by reaction at 90 ° C. for 1 hour.
The obtained aqueous dispersion was filtered under reduced pressure using a filter paper with a butter funnel to obtain a cake of core-shell particles.

The obtained cake was dried using a hot air dryer set at 105 ° C. to obtain core-shell particles. With respect to the obtained composite particles, the shortest distance (R _mini ) from the point of contact with the composite particle through the center point P of the silicone resin particle to the point of contact with the composite particle is 1. An imaginary straight line A having the longest distance between the intersections with the outer surface of the silicone core particle is drawn, and the imaginary straight line (A) is drawn from the center point (P) of the silicone resin core particle in this cross section. The longest distance (R _max ) to the contact point on the surface of the composite resin particle was 2.68 μm.

Table 1 shows the characteristics of the obtained composite particle group.
The SEM photograph of the silicone resin core particles used in Example 8 is shown in FIG. 26, the SEM particle group of the composite resin particle group is shown in FIG. 27, and the reflected light of the particle group obtained in Example 8 is shown in FIG. Indicates the rate of change.
[Comparative Examples 1 to 3]
As comparative examples, commercially available silicone particles (Comparative Example 1, manufactured by Momentive Performance Materials Japan, trade name: Tospearl 145A, average particle size (φsi) 4.5 μm), crosslinked polymethyl methacrylate particles (Comparative Example 2) , Manufactured by Soken Chemical Co., Ltd., trade name: MX-500, average particle diameter 5.0 μm), styrene particles (Comparative Example 3, manufactured by Soken Chemical Co., Ltd., trade name: SX-500H, average particle diameter 5. Table 1 shows the rate of change in the reflection intensity of these particles.

The change rate of the reflection intensity of the particle group obtained in Comparative Example 3 is shown in FIG.
[Comparative Example 4]
The mixed particles were adjusted by mixing at a ratio of 6.7 parts by weight of the particles of Comparative Example 1, 13.3 parts by weight of the particles of Comparative Example 2, and 80 parts by weight of the particles of Comparative Example 3, and the change in reflection intensity of the mixed particles The rates are shown in Table 1.

In the composite resin particles of the present invention, the core material particles are composed of silicone resin particles, and in the composite resin particles constituting the composite resin particles of the present invention, the silicone resin particles as the core material particles are the center of the composite resin particles. It is ubiquitously present. That is, despite the seed polymerization using resin core particles, the center point of the silicone resin core particles, which are seed particles, matches the center point of the composite resin particles obtained as a result of seed polymerization. First, the silicone resin core particles are present in a biased direction in any direction in the composite resin particles, and the composite resin particles occupy more than half, preferably the majority.

Thus, when the reflection direction of light is seen for each composite resin particle in which the silicone resin core particles are unevenly distributed, the unified reflection direction is not shown, but the composite of the present invention containing a large number of these composite resin particles. Regarding the resin particle group, when the reflection direction of the light is viewed, the reflected light cooperates to obtain reflected light with very high uniformity.

When a plurality of particles having different reflection characteristics that have been used in the past are mixed, the reflection characteristics of each particle become obvious, and the reflection characteristics that each particle does not have deteriorated. However, in the composite resin particle group of the present invention, the reflected light does not weaken and uniform reflected light can be obtained over all wavelengths.

DESCRIPTION OF SYMBOLS 10 ... Composite resin particle 20 ... Acrylic resin layer 30 ... Silicone resin core particle
D _si・・・ Diameter of silicone resin particles
R _mini・・・ Minimum length from the center of the silicone resin particle to the outer shell of the composite resin particle
R _max : Maximum length from the center of the silicone resin particle to the outer shell of the composite resin particle

Claims

Silicone resin core particles obtained by polymerizing a monomer component containing an acrylic monomer and / or a styrene monomer in the presence of silicone resin core particles having an average particle diameter in the range of 0.01 to 50 μm A composite resin particle group consisting of solid particles that are included,
In the cross section of the composite resin particle cut so as to expose the substantially center of the silicone resin core material particle included in the composite resin particle constituting the composite resin particle group,
It passes through the center of the cross section of the silicone resin core material particle, passes through the virtual straight line (A) having the longest distance between the intersections with the outer peripheral surface of the composite resin particle, and the center of the cross section of the silicone resin core material particle. And when assuming the virtual straight line (B) where the distance between the intersections with the outer peripheral surface of the composite resin particle is the shortest,
The center point (P) of the silicone resin core particle is from the center point (P) of the silicone resin core particle to the point where the virtual straight line (A) or (B) is in contact with the surface of the composite resin particle. The shortest distance (R mini ) and the longest distance (R) from the center point (P) of the silicone resin core particle to the point where the virtual line (A) or (B) contacts the surface of the composite resin particle a composite resin particle group comprising 50% by number or more of composite resin particles in a position having a relationship represented by the following formulas (1) and (2) with respect to max ):

(However, in the above formulas (1) and (2), Dsi represents the diameter of the silicone resin core particles in the cross section).
The composite resin particle group according to claim 1, wherein the formulas (1) and (2) are represented by the following formulas (1-1) and (2-1):

(However, in the above formulas (1-1) and (2-2), Dsi represents the diameter of the silicone resin core particles in the cross section).
The average particle diameter (φcp) of the composite resin particles constituting the composite resin particle group is in the range of 0.02 to 100 μm, and the average particle diameter (φsi) of the silicone resin core particles is 0.01 to 50 μm. The average distance x between the center point Q of the composite resin particle and the center point P of the silicone resin core particle is in the range of 0.005 to 50 μm. The composite resin particle group described.
The ratio (x /) of the average distance x between the center point Q of the composite resin particles constituting the composite resin particle group and the center point P of the silicone resin core particles and the average particle diameter (φcp) of the composite resin particles The composite resin particle group according to claim 1, wherein φcp) is in the range of 0.01 to 0.5.
3. The composite resin particle group according to claim 1 or 2, wherein the silicone resin core particles are mixed with an alkoxide of titanium / zirconium.
The composite resin particle group contains the composite resin particles having a sphericity in a range of 0.1 to 0.95 in an amount of 50% by number or more. The composite resin particle group described.
From the center point (Q) of the composite resin particle, the center point (P) of the silicone resin core material exists on the virtual straight line (C) radially radiated in the outward direction, and the virtual straight line (C) When the center point (Q) of the composite resin particle is the origin (0%) and the length to the intersection with the outer peripheral surface of the composite resin particle is 100%, the center point (P ) Is within the range of more than 0% and 99% or less of the imaginary straight line (C), the composite resin particle group contains 90% by number or more of the composite resin particles. The composite resin particle group according to Item 1.
2. The composite resin particle according to claim 1, comprising composite resin particles in which 10 to 80% by volume of the silicone resin core particles are exposed on the surface of the composite resin particles forming the composite resin particle group. group.
0.1 g of the composite resin particle group is uniformly applied to a urethane sheet having a width of 30 mm, a length of 50 mm, and a thickness of 3 mm, and using a goniophotometer, the incident angle is −45 °, the number of trials is n = 100. The variation rate of the reflection intensity measured under the above conditions (reflectance at a light receiving angle of 0 ° / average value of reflectance at a light receiving angle of −35 °) is in the range of 0.80 to 1.00. The composite resin particle group according to claim 1.
A cosmetic comprising the composite resin particle group according to any one of claims 1 to 9.
A light diffusing sheet comprising the composite resin particle group according to any one of claims 1 to 9.