JP5311929B2 - Spherical silica-based particles and cosmetics containing the silica-based particles - Google Patents

Description

  The present invention relates to spherical silica-based particles that are suitable as pigments, cosmetics and the like and have excellent oil absorption.

  Conventionally, inorganic oxide spherical particles such as silica, titanium oxide, and alumina, or these inorganic oxide spherical particles further containing an organic group, and resin-based spherical particles such as PMMA, nylon, silicone, polystyrene, etc. Used in makeup cosmetics and skin cosmetics such as emulsions. The blending effect of the spherical particles is an improvement in touch such as slipperiness due to rolling of the spherical particles on the skin. In the case of inorganic oxide-based particles, the hardness is high, so that a dry feel that is mainly smooth is obtained. In the case of resin-based particles, the hardness is relatively low, so that a soft feel is obtained.

  These feelings depend on the average particle size and particle size distribution of the spherical particles, as well as the physical or chemical properties of the substances constituting the particles. Specifically, the feeling of use when used as a cosmetic is influenced not only by the hardness of the particles but also by the chemical properties of the substances constituting the particles. For example, nylon having an amide bond has a characteristic that it can be easily adapted to the skin and give a smooth feeling of use.

  Classifying the particles based on the hardness scale, cosmetic powders that are currently highly commercially available include silicone rubber particles, while hard spherical powders are inorganic oxides such as silica. Examples include physical particles. The hardness of the resin spherical powder such as PMMA, polystyrene, silicone, nylon, etc. corresponds to the hardness between the former two. In the case of resin particles, even with the same type of resin, the hardness of the particles can be adjusted over a wide range, although the degree of hardness can be adjusted by adjusting the molecular structure by crosslinking, etc. It was difficult to adjust, and it was difficult to obtain spherical particles having the desired flexibility or hardness.

  JP-A-62-234008 [Patent Document 1], JP-A-62-181211 [Patent Document 2] and JP-A-3-18140 [Patent Document 3] are formulated with a spherical powder. It is disclosed that spherical particles having a pressure disintegration property are used as means for improving the feel of the material such as elongation and lightness of elongation.

  For example, in Japanese Patent Laid-Open No. 3-18140 [Patent Document 1], a slurry-like product in which a cosmetic powder and an inorganic colloid solution are dispersed in a dispersion medium at a predetermined ratio is spray-dried to obtain a predetermined shear fracture strength. The pressure disintegrating spherical powder shown and skin cosmetics containing the same have been proposed. This cosmetic has the effect of improving elongation and lightness on the skin by gradually disintegrating the pressure-disintegrating spherical particles due to shear stress when applied to the skin.

  However, the hardness or softness of different particles is required depending on the cosmetic preparation conditions or the type of cosmetic, and it is required to freely adjust the hardness or softness, pressure disintegration property, etc. of the spherical particles. ing. In addition, since the spherical particles gradually disintegrate during use, the slipperiness obtained by rolling the spherical particles without collapsing on the skin, or the dry and creamy feel obtained by smoothness cannot be obtained. Has a problem.

Japanese Patent Laid-Open No. 3-18140 JP-A-62-182111 Japanese Patent Laid-Open No. 3-18140

  An object of this invention is to provide the spherical silica type particle | grains which combined the outstanding oil absorption and compressive strength, and its manufacturing method. Another object of the present invention is to provide a cosmetic that is excellent in oil absorption and that is excellent in elongation and lightness (smooth feeling) on the skin.

The spherical silica-based particles of the present invention comprise a silica fine particle dispersion in which silica fine particles having an average particle size of 10 to 300 nm are dispersed in a dispersion medium and an aqueous dispersion of biocellulose. .Spherical silica-based particles obtained by spray-drying the dispersion mixed so as to be 1 to 20 parts by mass, and having an average particle diameter in the range of 1 to 100 μm and a pore volume of 0.5 to 3. It is characterized by being in the range of 0 ml / g.
The spherical silica-based particles of the present invention include 100 parts by mass of silica fine particles having an average particle diameter in the range of 10 to 300 nm and 0.1 to 20 parts by mass of biocellulose. The volume is in the range of 0.5 to 3.0 ml / g.
The oil absorption of the silica-based particles is preferably in the range of 100 to 400 ml / 100 g, and the compressive strength is preferably in the range of 1 to ²⁰ Kgf / mm ² .

  The cosmetic of the present invention contains the spherical silica-based particles.

  The method for producing spherical silica-based particles of the present invention comprises 100 parts by mass (solid content conversion) of silica fine particle dispersion medium in which silica fine particles having an average particle diameter in the range of 10 to 300 nm are dispersed in a dispersion medium, and biocellulose dispersion A liquid mixture containing 0.1 to 20 parts by mass (in terms of solid content) of the liquid is spray-dried.

The spherical silica-based particles according to the present invention are particles having both excellent oil absorption and compressive strength. In addition, the cosmetic comprising the silica-based particles according to the present invention can absorb and remove excess sebum and suppress makeup collapse.

1. Spherical Silica Particles The spherical silica particles according to the present invention are obtained by spray-drying a dispersion obtained by mixing a silica fine particle dispersion in which silica fine particles are dispersed in a dispersion medium and an aqueous dispersion of biocellulose. The silica-based particles are substantially spherical particles containing silica fine particles and biocellulose. Although the physical properties of the silica-based particles tend to depend on the mass ratio of the silica fine particles and the biocellulose constituting the silica-based particles, the oil absorption per unit mass is higher than that of the silica fine particles, and the compressive strength of the particles is practical. To maintain a high level.

  The average particle diameter of the silica-based particles according to the present invention is preferably in the range of 1 to 100 μm. When the average particle diameter of the silica-based particles is less than 1 μm, the average pore diameter of the particles is small, and the oil absorption is reduced. On the other hand, when the average particle diameter of the silica-based particles exceeds 100 μm, the usability may be deteriorated. As a more preferable average particle diameter range of the silica-based particles, a range of 2 to 15 μm is recommended. In addition, the particle diameter of the said silica type particle means the particle diameter measured by the centrifugal sedimentation method.

The pore volume of the silica-based particles needs to be in the range of 0.5 to 3.0 ml / g.
When the pore volume of the silica-based particles is less than 0.5 ml / g, when used as a cosmetic, the oil absorption is low, which may cause problems in practice. On the other hand, when the pore volume exceeds 3.0 ml / g, the structure of the silica-based particles becomes brittle, which may cause a practical problem. The pore volume of the silica-based particles is more preferably in the range of 0.7 to 2.0 ml / g. The silica-based particles according to the present invention take the pore volume range and can be regarded as so-called porous particles (or spherical porous silica-based particles).

The silica-based particles according to the present invention preferably have an oil absorption of 100 to 400 ml / 100 g and a compressive strength of 1 to 20 kgf / mm ² . For example, when the silica-based particles having an oil absorption amount in this range are applied to cosmetics, the effect of absorbing and removing excess sebum and suppressing makeup collapse is seen. Further, when the compressive strength is in the above range, a sufficient smooth feeling can be imparted to the cosmetic. In addition, the oil absorption amount in this invention is converted into the oil absorption amount with respect to oil in boiled sea bream. The measuring method will be described later.
When the amount of oil absorption is less than 100 ml / 100 g, the above-described effect of suppressing makeup collapse may not be sufficiently observed. On the other hand, when the oil absorption exceeds 400 ml / 100 g, other cosmetic ingredients may be adversely affected. When the compressive strength is less than 1 Kgf / mm ² , the particles are broken, the slipperiness is deteriorated, and the tendency to easily become rough is increased. On the other hand, when the compressive strength exceeds ²⁰ Kgf / mm ² , wear between particles is increased, and problems such as poor softness are likely to occur. In addition, the compressive strength [Kgf / mm ² ] of the spherical silica-based particles according to the present invention means that measured under predetermined conditions by a micro compression tester described later.

Silica fine particles The average particle size of the silica fine particles contained in the silica-based particles is preferably in the range of 10 to 300 nm. An average particle diameter of less than 10 nm is not preferable because the silica-based particles may not have a pore volume sufficient to exhibit sufficient oil absorption. In addition, when the average particle diameter exceeds 300 nm, the transparency of the silica fine particle itself is significantly reduced. In addition, about the particle diameter of the said silica particle, the particle diameter measured by the dynamic light scattering method is meant.
As the silica fine particle dispersion, a known silica fine particle dispersion (silica sol) can be used. Examples of the method for producing the silica-based fine particle dispersion include, but are not limited to, the following production methods (1) to (4).

(1) A silicic acid solution obtained by dealkalizing a water-soluble silicate selected from alkali metal silicate, tertiary ammonium silicate, quaternary ammonium silicate or guanidine silicate is heated in the presence of alkali. A method for producing a silica sol comprising a step of polymerizing silicic acid. As an example of this production method, first, an alkali silicate aqueous solution is diluted with water to a silica concentration of 3 to 10% by weight, and then converted into an H-type strongly acidic cation exchange resin. Contact is dealkalized and, if necessary, contacted with an OH type strongly basic anion exchange resin to deanion to prepare active silicic acid. Next, a method of producing a silica sol having an average particle diameter of 60 nm or less by adding an alkali substance so that the pH becomes 8 or more and heating to 50 ° C. or more can be mentioned.

(2) Manufacturing method of silica sol for growing core particles by adding acidic silicic acid solution to the core particle dispersion In this manufacturing method, the core particle dispersion is not particularly limited as long as it functions as core particles. Conventionally known fine particle dispersions such as silica, alumina, zirconia, ceria, titania, silica-alumina, silica-zirconia, silica-ceria, silica-titania can be used. Among these, silica sols and silica-based composite oxide sols disclosed in Japanese Patent Application Laid-Open Nos. 5-132309 and 7-105522 by the applicant of the present application are preferable because silica particles having a uniform particle size distribution can be obtained.

It is preferable that an alkali silicate is added to the core particle dispersion before addition of the acidic silicate solution. When the alkali silicate is added, when the acidic silicate liquid for particle growth is added next, the SiO ₂ concentration dissolved in the dispersion medium is increased in advance, so that precipitation of silicic acid on the core particles occurs early, Further, the pH of the dispersion can be adjusted to about 8 to 12, preferably 9.5 to 11.5. As the alkali silicate used here, it is preferable to use a solution in which silica is dissolved in an organic base such as potassium silicate (potassium water glass), silicate alkali other than sodium silicate (sodium water glass), or quaternary amine. Moreover, alkali metal hydroxides other than NaOH, ammonium, and quaternary ammonium hydride can be added as needed. Furthermore, alkali metal hydroxides such as Mg (OH) ₂ , Ca (OH) ₂ , Sr (OH) ₂ and Ba (OH) ₂ can be preferably used.

Even if the core particles are not dispersed in advance, the core particles are generated when the silica concentration is increased when an acidic silicic acid solution described later is added to the alkali silicate aqueous solution. Therefore, such a core particle dispersion is also preferably used. be able to. The concentration of the core particle dispersion varies depending on the size of the core particles, but it is preferably in the range of 0.005 to 20% by weight, more preferably 0.01 to 10% by weight as SiO ₂ .
When the concentration of the core particles is less than 0.005% by weight, some or all of the core particles may be dissolved when the temperature is increased to perform particle growth. If the effect of using the liquid is not obtained, and part of the core particles is dissolved, the particle diameter of the silica particles obtained tends to be non-uniform, and the effect of using the core particle dispersion may not be obtained as well. is there. On the other hand, when the concentration of the core particles exceeds 20% by weight, the addition rate of the silicic acid solution is increased in order to make the addition ratio of the acidic silicic acid solution per core particle the same as the low concentration. Precipitation of the acidic silicic acid solution on the surface of the core particles cannot follow, and the acidic silicic acid solution may gel.
The average particle diameter of the core particles is not particularly limited as long as the silica particles described above can be obtained.

(3) A method for producing a silica sol comprising a step of washing a silica hydrogel obtained by neutralizing a silicate with an acid, removing salts, adding an alkali, and heating the silica hydrogel by heating. The production method is called a peptization method. Usually, a silica hydrogel is prepared by neutralizing an aqueous solution of silicate with an acid, and the silica hydrogel is slurried or dispersed by chemical or mechanical means. It is known as a method of making a solution.

Here, as a chemical means, the method of adding an alkali to a silica hydrogel and heating as desired is mentioned. Moreover, as a mechanical means, the method of using apparatuses, such as a stirrer, can be mentioned. These chemical means and mechanical means may be used in combination.
Specifically, silica hydrogel obtained by neutralizing silicate with acid is washed, salts are removed, alkali is added, and the silica hydrogel is peptized by heating in the range of 60 to 200 ° C. Then, a silica sol is prepared.

  The silicate used as a raw material in this production method is preferably one or more silicates selected from alkali metal silicates, ammonium silicates, and organic base silicates. Examples of the alkali metal silicate include sodium silicate (water glass) and potassium silicate, and examples of the organic base include quaternary ammonium salts such as tetraethylammonium salt, amines such as monoethanolamine, diethanolamine, and triethanolamine. In addition, the ammonium silicate or the organic base silicate includes an alkaline solution obtained by adding ammonia, a quaternary ammonium hydroxide, an amine compound, or the like to a silicic acid solution.

(4) A method for producing a silica sol comprising a step of hydrolyzing a silicon compound having a hydrolyzable group and polymerizing the resulting silicic acid As an example of this production method, water-organic in which seed particles are dispersed A method of producing monodispersed silica particles by adding tetraethoxysilane to a solvent-based dispersion, hydrolyzing the tetraethoxysilane, attaching silica onto the seed particles, and performing particle growth. Are known.

  About the solid content density | concentration of the silica type sol used as a raw material, the thing of the range of 10-50 mass% is used. Further, a silica-based sol is preferably in a monodispersed state in order to make the particle diameter uniform in a later step. Of course, a commercially available silica sol can be applied as a raw material. In that case, it is economical to use a commercially available product having a high silica concentration of 20 to 50%. Further, before use, ion exchange, filtration, concentration adjustment, etc. may be performed as desired.

About the mixing amount of the biocellulose (solid content conversion) with respect to 100 mass parts of biocellulose silica fine particles, the range of 0.1-20 mass parts is preferable. When the mixing amount of the biocellulose is less than 0.1 parts by mass, the shrinkage after spray drying is large, the pore volume of the obtained silica-based particles may be reduced, and the oil absorption may be reduced. On the other hand, when the mixing amount of biocellulose (in terms of solid content) exceeds 20 parts by mass, the shape retention of particles may be reduced although the shrinkage after spray drying is small. As a more preferable mixed amount range of biocellulose (in terms of solid content) with respect to 100 parts by mass of silica fine particles, a range of 1 to 10 parts by mass can be mentioned.

  Biocellulose is highly crystalline, has an ultrafine structure with a uniform width, and has a high degree of weight average polymerization compared to conventional vegetable cellulose. Therefore, when dispersed in water, it is highly viscous and excellent in suspension stability. Hereinafter, biocellulose will be described in detail.

Biocellulose is also called bacterial cellulose, and means, for example, cellulose produced by culturing microorganisms such as acetic acid bacteria. Most plant cellulose is produced by higher plants, but cellulose produced by microorganisms other than plants is called biocellulose (or bacterial cellulose). As for biocellulose, for example, one type of acetic acid bacteria produces a gel-like cellulose film on the surface of the medium when cultured. Such biocellulose has properties different from plant cellulose.
The difference between biocellulose and plant cellulose is in its microstructure. Plant cellulose is known to have many cellulose molecular chains converged to form fine fibers called microfibrils, and these microfibrils converge to form higher-order structures step by step from the fibrils. .

Biocellulose, on the other hand, is a ribbon-like structure in which cellulose microfibrils secreted from fungal cells form a net-like structure with the same thickness, and generally have a thickness of 1 to 20 nm and a width of 10 nm to 1 μm. It has a microfibril structure. Usually, it is gel-like and the water content is 95% (w / v) or more.
The structure of biocellulose includes cellulose and a heteropolysaccharide having cellulose as a main chain, or includes glucan. Components other than cellulose in the case of containing a heteropolysaccharide are hexoses such as mannose, fructose, galactose, xylose, arabinose, rhamnose or glucuronic acid, pentoses or organic acids. In addition, about these polysaccharides, a single substance may be sufficient and 2 or more types of polysaccharides may be mixed by the hydrogen bond etc. Any biocellulose can be used as long as it is as described above.

  In addition to a purified product separated from a culture of microorganisms, biocellulose may contain impurities to some extent depending on the application. For example, residual saccharide, yeast extract, etc. in the culture solution may remain microbial cellulose. Moreover, the microbial cell may be contained to some extent.

  The microorganism that produces such biocellulose is not particularly limited. For example, Acetobacteraceti subsp / xylinum ATCC 10821 or A. pasteurianus, A. rancens, Sarcina ventriculi, Bacterium xyloides), Pseudomonas bacteria, Agrobacterium bacteria and the like.

  Regarding the biocellulose to be applied to the present invention, a commercially available product may be applied as it is, or gelled biocellulose so that the biocellulose fibers are prevented from sticking and the silica fine particles can be uniformly dispersed in the dispersion. May be finely pulverized to form a slurry, or dried to form a powder, and then applied to the production method according to the present invention. Here, the pulverization method of biocellulose is not particularly limited, and for example, a method of shearing by rotating at high speed in water with a homogenizer or a method of mechanical shearing after acid hydrolysis treatment is used. be able to.

2. Method for Producing Silica-Based Particles The method for producing silica-based fine particles according to the present invention comprises 100 parts by mass (in terms of solid content) of silica fine particle dispersion having an average particle size in the range of 10 to 300 nm, and biocellulose dispersion 0.1. -20 mass parts (solid content conversion) are mixed, a liquid mixture is prepared, and this liquid mixture is spray-dried, It is characterized by the above-mentioned.
As the solvent of the mixed solution, water or an organic solvent is used. As the organic solvent, monohydric alcohols such as ethanol, propanol and butanol, polyhydric alcohols such as ethylene glycol, and the like can be used.

  About the density | concentration of the said spraying liquid, it is preferable to exist in the range of 5-60 weight% in conversion of solid content, especially 10-50 weight%. When the solid content concentration of the spray liquid is less than 5% by weight, it is difficult to obtain an aggregate of silica fine particles and biocellulose. When the concentration of the spray solution exceeds 60% by weight, the spray solution becomes unstable and it becomes difficult to obtain a spherical aggregate. Moreover, the spray-drying mentioned later cannot be performed continuously, and the yield of an assembly falls.

  The spray drying method of the spray liquid is not particularly limited as long as the above-described aggregate can be obtained, and conventionally known methods such as a rotating disk method, a pressure nozzle method, and a two-fluid nozzle method can be employed. In particular, the two-fluid nozzle method disclosed in Japanese Examined Patent Publication No. 2-61406 is preferable because it can obtain spherical fine particle aggregates having a uniform particle size distribution and can easily control the average particle size. .

The drying temperature at this time varies depending on the concentration of the spray liquid, the processing speed, etc., but when using a spray dryer, for example, the inlet temperature of the spray dryer is 100 to 400 ° C., and the spray speed is 0.5 to 3 L / min. The conditions such as the outlet temperature of 40 to 200 ° C. are preferable.
When the inlet temperature is less than 100 ° C., the drying is insufficient and the spherical shape is not obtained, the irregular shaped particles increase, and the problem of dispersibility tends to occur. When the temperature exceeds 400 ° C., the network structure is decomposed due to the oxidation of biocellulose, which may result in a colored powder.
On the other hand, when the outlet temperature is less than 40 ° C., the drying is insufficient and the spherical shape is not obtained, and irregular shaped particles are increased, which tends to cause a problem of dispersibility. When the temperature exceeds 200 ° C., the condensation of silanol groups on the surface of the silica particles is promoted, the particles shrink significantly, and there are problems that the particles become irregular due to cracking.

3. Cosmetics containing spherical silica-based particles Specific cosmetics include solid cosmetics such as foundations and white powders, powdery cosmetics such as body powders and baby powders, emulsions, creams, lotions, lotions, etc. And liquid cosmetics, sheet-like cosmetics such as wiping sheets and oil collecting paper.

  The blending ratio in these cosmetics varies depending on the type of cosmetic, but it is preferably 1 to 20% by weight, more preferably 3 to 15% by weight for solid cosmetics such as funny and foundation. The Moreover, in the case of powdery cosmetics, 1 to 20 weight% is preferable, More preferably, 3 to 15 weight% is recommended. In the case of liquid cosmetics, 1 to 15% by weight is preferable, and 3 to 10% by weight is more preferable. In the case of a sheet-like cosmetic, 1 to 20% by weight is preferable, and more preferably 1 to 15% by weight is recommended.

  In the cosmetic, other necessary components can be used in addition to the silica-based particles. For example, in order to improve slipperiness, it can be used by mixing with organic resin particles, ordinary silica, or the like. In order to improve touch, inorganic fine particles such as mica, pigments such as iron oxide, titanium oxide, ultramarine blue, bitumen, and carbon black, or synthetic dyes may be added.

In the case of liquid cosmetics, the liquid medium is not particularly limited, but water, alcohol, organic oil, silicone oil, fats and the like can also be used.
In the case of sheet-like cosmetics, any of woven or non-woven fabrics of natural fibers or synthetic fibers can be used as the base material.
Moreover, you may add an antibacterial agent, a moisturizer, a whitening agent, UV shielding agent, an antiperspirant, a deodorant, a fragrance | flavor etc. to the said cosmetics other than said other component.

The cosmetic of the present invention can absorb and remove excess sebum and suppress makeup collapse by using spherical silica-based particles having a high oil absorption.
Next, the measurement methods employed in the examples and others of the present invention will be specifically described as follows.

[Measuring method of average particle size by dynamic light scattering method]
For the average particle size of the silica fine particles, the sample silica fine particle dispersion was diluted with 0.58% ammonia water to adjust the solid content concentration to 1% by mass, and a particle size measuring device (manufactured by Otsuka Electronics Co., Ltd., laser particle size). Analysis system: LP-510 model PAR-III).

[Measurement method of average particle size by centrifugal sedimentation]
Regarding the average particle diameter of the spherical silica-based particles, first, a dispersion of spherical silica-based particles (water or 40% by mass glycerin solvent, solid content concentration 0.1 to 5% by mass) is converted into an ultrasonic generator (manufactured by Iuch, Disperse in US-2) for 5 minutes. Further, from a dispersion whose concentration has been adjusted moderately by adding water or glycerin, the dispersion is taken into a glass cell (size of 10 mm in length, 10 mm in width, and 45 cm in height), and a centrifugal sedimentation type particle size distribution analyzer (Horiba) The average particle diameter was measured using a mill manufactured by CAPA-700.

[Measurement method of pore volume]
Regarding the pore volume of the spherical silica-based particles, first, 10 g of a sample made of spherical silica-based particles was placed in a crucible, dried at 300 ° C. for 1 hour, then placed in a desiccator and cooled to room temperature. Next, a 1 g sample was taken in a well-washed cell, and nitrogen was adsorbed using a nitrogen adsorption device (manufactured in-house), and the pore volume was calculated from the following equation.
Pore volume (ml / g) = (0.001567 × (V−Vc) / w)
However, 0.001567: Ratio of density of nitrogen gas and liquid nitrogen, V: Adsorption amount in a standard state at a pressure of 735 mmHg (ml), Vc: Cell blank (ml) at a pressure of 735 mmHg, W: Sample weight (g) It is.

[Measurement method of oil absorption]
1.5 g of powder composed of spherical silica-based particles is collected on a medicine wrapping paper and transferred to a glass measuring plate. Next, boiled oil (specified in JISK5101) is dropped 4.5 times at a time onto the sample from the burette, and the whole is kneaded with a spatula. The dripping and kneading are repeated, and the oil absorption amount is calculated by the following formula, with the end point being the time when one mass is obtained. In the following formula, A represents a dripping amount (ml) of boiled sesame oil, and W represents a sampled amount (g).
Oil absorption (ml / 100g) = (A / W) × 100

[Measurement method of compressive strength]
Take one spherical silica-based particle with an average particle diameter of ± 0.5μm as a sample, and apply a load to this sample at a constant load speed using a micro compression strength tester (manufactured by Shimadzu Corporation, MCTM-200). The compressive strength (kgf / mm ² ) is defined as the weight when the particles are loaded and the particles are broken. Further, this operation is repeated four times, and the compressive strength is measured for five samples, and the average value is taken as the particle compressive strength.

500 g of the silica dispersion (average particle size 70 nm, solid content concentration 20% by mass) was added to 100 g of the biocellulose dispersion (1% by mass) and mixed with stirring to obtain a spray solution.
This biocellulose has a microfibril structure having a thickness of 5 nm and a width of 130 nm (average value) produced by stationary culture. Also in the following examples and comparative examples, aqueous dispersions having different concentrations with the same biocellulose were used.

This spray solution is applied to a spray dryer (NIRO ATMIZER, manufactured by NIRO), spray-dried under the conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute, an average particle diameter of 5 μm, and a pore volume. A silica-based particle of 0.76 ml / g was obtained.
The obtained silica particles are measured for oil absorption and compressive strength, and the results are shown in Table 1 together with the measurement results of the following Examples and Comparative Examples.

500 g of the silica dispersion (average particle size 80 nm, solid content concentration 20% by mass) was added to 100 g of the biocellulose dispersion (5% by mass) and mixed by stirring to obtain a spray solution.
This spray solution is applied to a spray dryer (NIRO ATMIZER, manufactured by NIRO), spray-dried under the conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute, and an average particle size of 10 μm and a pore volume. 0.90 ml / g silica-based particles were obtained.

500 g of the silica dispersion (average particle size 80 nm, solid content concentration 20% by mass) was added to 100 g of the biocellulose dispersion (10% by mass), and stirred and mixed to obtain a spray solution.
This spray solution is applied to a spray dryer (NIRO ATMIZER, manufactured by NIRO), spray drying is performed under the conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute, an average particle diameter of 7 μm, and a pore volume. 1.10 ml / g silica-based particles were obtained.

500 g of the silica dispersion (average particle size 150 nm, solid content concentration 20% by mass) was added to 100 g of the biocellulose dispersion (1% by mass), and stirred and mixed to obtain a spray solution.
This spray solution is applied to a spray dryer (NIRO ATMIZER, manufactured by NIRO), spray-dried under the conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute, an average particle diameter of 40 μm, and a pore volume. Silica-based particles of 1.00 ml / g were obtained.

500 g of the silica dispersion (average particle size 70 nm, solid content concentration 20% by mass) was added to 100 g of the biocellulose dispersion (15% by mass), and mixed by stirring to obtain a spray solution.
This spray solution is applied to a spray dryer (NIRO ATMIZER, manufactured by NIRO), spray-dried under the conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute, an average particle diameter of 5 μm, and a pore volume. 2.01 ml / g of silica-based particles were obtained.

Comparative Example 1

100 g of silica particles (average particle size 1000 nm) was added to 400 g of pure water, and mixed by stirring to obtain a spray solution.
This spray solution is applied to a spray dryer (NIRO ATMIZER, manufactured by NIRO), spray-dried under the conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute, an average particle diameter of 50 μm, and a pore volume. 0.3 ml / g of silica-based particles was obtained.

Comparative Example 2

100 g of silica particles (average particle diameter 500 nm) was added to 400 g of pure water, and mixed by stirring to obtain a spray solution.
This spray solution is applied to a spray dryer (NIRO ATMIZER, manufactured by NIRO), spray-dried under the conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute, an average particle diameter of 50 μm, and a pore volume. 0.3 ml / g of silica-based particles was obtained.

Comparative Example 3

500 g of the silica dispersion (average particle size 70 nm, solid content concentration 20% by mass) was added to 100 g of the biocellulose dispersion (30% by mass), and stirred and mixed to obtain a spray solution.
This spray solution is applied to a spray dryer (NIRO ATMIZER, manufactured by NIRO), spray-dried under the conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute, an average particle diameter of 5 μm, and a pore volume. A silica-based particle of 0.76 ml / g was obtained.

Comparative Example 4

  100 g of the biocellulose dispersion (1% by mass) is used as a spray solution, and is applied to a spray dryer (NIRO, manufactured by NIRO ATMIZER). It is spray-dried under conditions of an inlet temperature of 280 ° C., an outlet temperature of 110 ° C., and a spray rate of 2 liters / minute. Carried out. As a result, amorphous particles made of biocellulose having an irregular shape and a pore volume of 0.98 ml / g were obtained.

  The spherical silica-based particles according to the present invention are excellent in oil absorption and can be suitably used for applications such as cosmetics and pigments.

2 is a scanning electron micrograph (magnification 20000 times) of the spherical silica-based particles obtained in Example 1. FIG.

Claims (4)

An average particle size of 10~300nm silica fine particle dispersion silica fine particles are dispersed in a dispersion medium, a thickness of 1 to 20 nm, and a water-based dispersion of biocellulose with microfibril structure of the ribbon-like wide 10nm~1μm In addition, spherical silica-based particles obtained by spray-drying a dispersion mixed so as to be 0.1 to 20 parts by mass of biocellulose with respect to 100 parts by mass of silica, and having an average particle diameter of 1 to 100 μm range, range pore volume of 0.5~3.0ml / g, spherical silica-based particles compressive strength lies in the range of 1~20Kgf / mm ^2. 100 parts by mass of silica fine particles having an average particle size in the range of 10 to 300 nm, and 0.1 to 20 parts by mass of biocellulose having a ribbon-like microfibril structure having a thickness of 1 to 20 nm and a width of 10 nm to 1 μm , A spherical silica-based particle having an average particle diameter in the range of 1 to 100 μm, a pore volume in the range of 0.5 to 3.0 ml / g, and a compressive strength in the range of 1 to ²⁰ kgf / mm ² . 3. The spherical silica-based particle according to claim 1, wherein an oil absorption amount of the silica-based particle is in a range of 100 to 400 ml / 100 g.   A cosmetic comprising the spherical silica-based particles according to claim 1, 2 or 3.