JPH0867505A - Inorganic oxide particle - Google Patents

Abstract

PURPOSE: To obtain inorganic oxide particles capable of readily handling and readily re-dispersing into water, an organic solvent, a resin, etc., by spraying and drying an inorganic oxide colloid solution in which fine particles (children particles) having average particle diameter and particle diameter distribution in the specific range are dispersed. CONSTITUTION: An inorganic oxide colloid solution in which inorganic oxide fine particles (children particles) having 0.1-1.0μm average particle diameter and >=50% ratio of particle diameter distribution occupied within the range of particle diameter of the average particle diameter ±30% are dispersed is sprayed and dried and as necessary, baked to afford the objective inorganic oxide particles (mother particles) having about 10-200μm average particle diameter. The particles have dispersibility satisfying a relationship expressed by the formula 1. 0<=Dpm /Dpc <=2.0 where average particle diameter of children particles is defined as Dpc and average disperse particle diameter when the mother particles are dispersed in water is defined as Dpm . The inorganic oxide constituting the children particles includes a monoxide, a mixture of oxides or a complex oxide, e.g. Al2 O3 , SiO2 , SnO2 -Sb2 O3 or SiO2 -Al2 O3 -Ag2 O.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to inorganic oxide particles (mother particles) formed by aggregating inorganic oxide fine particles (child particles). More specifically, the inorganic oxide particles (mother particles) are constituted. The present invention relates to inorganic oxide particles (mother particles) that can be redispersed in inorganic oxide fine particles (child particles).

[0002]

2. Description of the Related Art Inorganic oxide particles (mother particles) formed by aggregating a large number of inorganic oxide fine particles (child particles) are already known, and, for example, JP-A-56-120511 discloses aluminosilicate coating. Porous powder having a substantially uniform pore size consisting of agglomerates of spherical particles having, and a method for producing the same, by drying an aluminosilicate aqueous sol having particles of uniform size without gelation. A method for producing a porous powder, which comprises forming a powder, is disclosed.

However, these conventional inorganic oxide particles (mother particles) including the above publications could not be redispersed in the inorganic oxide fine particles (child particles) constituting them. Further, conventionally, research has been focused on how to agglomerate the inorganic oxide fine particles (child particles) in order to increase the specific surface area, etc., and the inorganic oxide particles (mother particles) Regarding the above, there was no recognition itself of redispersing it in the inorganic oxide fine particles (child particles) constituting the same.

[0004]

OBJECTS OF THE INVENTION The present inventors have found that for specific applications such as various additives such as deodorants and film fillers, the inorganic oxide particles (matrix) which are easily redispersed in the inorganic oxide particles (child particles) can be used. Based on the idea that the application of particles will be extremely effective, the present invention has been made as a result of intensive research. That is, the object of the present invention is inorganic oxide particles (mother particles)
The object is to provide redispersible inorganic oxide particles (mother particles) into a single inorganic oxide fine particle (child particle) constituting the above.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The inorganic oxide particles according to the present invention are inorganic oxide particles (mother particles) formed by aggregating inorganic oxide fine particles (child particles), and satisfy the following formula [1]: It is a feature. 1.0 ≤ Dpm / Dpc ≤ 2.0 ... [1] However, in the formula [1], Dpc is an inorganic oxide fine particle (child particle).
Represents the average particle diameter (μm), and Dpm represents the average particle diameter (μm) of dispersed particles when inorganic oxide particles (mother particles) are dispersed in water.

The average particle size of the inorganic oxide fine particles (child particles) is in the range of 0.1 to 1.0 μm, and the ratio of the particle size distribution to the average particle size ± 30% of the particle size range. It is preferably 50% or more.

[0007]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, the shape of the inorganic oxide fine particles (child particles) is not particularly limited,
A spherical shape is particularly preferable. The average particle size is 0.1 to 1.0 μm, preferably 0.3 to 0.6 μm.
It is desirable to be in the range of.

The average particle size of the fine particles (child particles) is 0.1.
When the particle size is less than μm, when the particles are aggregated to form inorganic oxide particles (mother particles), the binding force between the child particles becomes strong, and thus the obtained particles (mother particles) are redispersed in the child particles. In general, it becomes difficult to satisfy the formula [1] described later. The average particle size of the fine particles (child particles) is 1.0
When it exceeds μm, it is difficult to maintain the shape of aggregated particles (mother particles) because the binding force between the child particles is weak.

It is desirable that the size of the inorganic oxide fine particles (child particles) be as uniform as possible. Specifically, it is desirable that the particle size distribution occupy 50% or more, preferably 60% or more, in the range of the average particle size ± 30%. Fine particles having a small particle size, even if the average particle size is in the range of 0.1 to 1.0 μm, when the ratio of the particle size distribution in the range of the particle size of the average particle size ± 30% is less than 50%. The presence of the (child particles) increases the binding force between the child particles and deteriorates the redispersibility in a single child particle, which is not desirable.

In the present invention, examples of the inorganic oxide constituting the inorganic oxide fine particles (child particles) include a single oxide, a mixture of oxides, and a composite oxide. For example, Al ₂ O ₃ , SiO ₂ , TiO ₂ , ZrO
₂ , Fe ₂ O ₃ , Sb ₂ O ₅ , ZnO, MgO, Ca
_{O, CuO, SiO 2 -Al 2} O 3, TiO 2 -Al 2
_{O 3, SnO 2 -Sb 2 O} 3, TiO 2 -ZrO 2, S
_{iO 2 -TiO 2, SiO 2 -Al} 2 O 3 -MgO, S
_{iO 2 -Al 2 O 3 -Ag 2} O, SiO 2 -TiO 2 -
_{Fe 2 O 3, SiO 2 -Al} 2 O 3 -CaO, SiO 2
_{-TiO 2 -Al 2 O 3, SiO} 2 -Al 2 O 3 -Zn
O, etc. can be mentioned.

The inorganic oxide particles (mother particles) of the present invention are obtained by aggregating the above-mentioned inorganic oxide fine particles (child particles), and the particles (mother particles) are mixed with water or a suitable organic solvent, or When mixed in these mixed solvents, or in a synthetic resin or a film-forming agent (vehicle), they are easily redispersed into single fine particles (child particles) constituting the inorganic oxide particles (mother particles). That is, the inorganic oxide particles (mother particles) are characterized by satisfying the following formula [1]. 1.0 ≤ Dpm / Dpc ≤ 2.0 ... [1]

In the formula [1], Dpc represents the average particle diameter (μm) of the inorganic oxide fine particles (child particles), and Dpm represents the dispersion when the inorganic oxide particles (mother particles) are dispersed in water. The average particle diameter (μm) of the particles is shown. As for Dpm, a sample of inorganic oxide particles (mother particles) was dispersed in a 0.2 wt% polyphosphoric acid aqueous solution so as to have a concentration of 45 mg / ml, and sufficiently sonicated at a wavelength of 19.5 K for 15 minutes. The average particle size of the dispersed particles after that was measured.

When the value of Dpm / Dpc is 1, it means that the average particle size of the child particles before they are aggregated in the mother particles is equal to the average particle size of the dispersed particles when the mother particles are dispersed in water. , Indicating that the dispersibility is extremely good. On the other hand, when the value of Dpm / Dpc exceeds 2, it indicates that the redispersibility in a single child particle is poor, and the inorganic oxide particles (mother particles) are dispersed in water, other solvent or resin. Since the property is poor, the desired effect cannot be obtained even if it is applied to the above-mentioned specific use.

As the organic solvent with which the inorganic oxide particles (mother particles) are mixed, solvents such as alcohols, glycols, esters, ketones and aromatics can be used, and specifically, methanol, ethanol. , Propanol, ethylene glycol, propylene glycol, glycerin, acetone, methyl ethyl ketone, methyl cellosolve, ethyl cellosolve, dimethylformamide, N-
Examples thereof include organic solvents such as methyl-2-pyrrolidone.

The synthetic resin is a phenol resin,
Urea resin, melamine resin, polyester resin, epoxy resin, silicon resin, vinyl chloride resin, vinylidene chloride resin, vinyl fluoride resin, vinyl acetate resin, polyvinyl alcohol resin, fluororesin, polyethylene resin, polypropylene resin, polystyrene resin, acrylic ester Resins, methacrylic resins, polyamide resins, polyacetal resins, chlorinated polyether resins, polycarbonate resins and the like can be mentioned.

As the coating film forming agent (vehicle), boil oil, oil varnish, nitrocellulose, vinyl resin, alkyd resin, amino resin, epoxy resin, phenol resin, polyester resin, polyurethane resin, acrylic resin, fluorine is used. Resin, silicon resin, chlorinated rubber and the like are exemplified. Of course, these may be used alone or in combination of two or more compounds.

The average particle diameter of the above-mentioned particles can be measured by measuring the change in particle concentration while rotating the sedimentation cell at a constant speed, or by measuring the change in turbidity by light transmission.
Further, it can be measured by a so-called centrifugal type particle size distribution measuring method, which detects the movement of the center of gravity of the rotating cell due to the sedimentation of particles.

The size and shape of the inorganic oxide particles (mother particles) of the present invention are not particularly limited, but spherical particles having an average particle diameter in the range of 10 to 200 μm are handled. It is particularly preferable from the above points.

The inorganic oxide particles (mother particles) of the present invention are produced, for example, by the following method. That is, an inorganic oxide colloidal solution in which fine particles (child particles) having an average particle diameter and a particle diameter distribution within the above-mentioned specific range are dispersed is spray-dried, and optionally fired to form inorganic oxide particles (mother particles).
To get Note that spray drying and firing can be performed by an ordinary method. For example, spray drying should be performed at a temperature of about 100 to several hundreds of degrees Celsius using a device such as a rotating disk system or a pressure nozzle system. You can Also, firing is performed in air at 30
It can be performed at a temperature of 0 to 800 ° C. for 1 to several hours.

The inorganic oxide colloidal solution in which fine particles having the above-mentioned specific average particle size and particle size distribution are dispersed is, for example, a colloidal solution in which colloidal particles having a small particle size are dispersed. Can be prepared by a known method or the like in which the particles are grown to obtain colloidal particles having a desired particle size.

[0021]

The inorganic oxide particles (mother particles) of the present invention are
Since the particle size is relatively large, it is easy to handle, and when added to water, organic solvents, resins, etc., the particles (mother particles)
Is easily redispersed in the fine particles (child particles) that make up it, so various additives such as deodorants and film fillers,
It is suitable for applications such as cosmetics, pigments, paints, and fillers for plastics.

[0022]

EXAMPLES The present invention will be described in more detail with reference to the following examples.

Example 1 Silica sol having an average particle diameter of 300 nm (Catalyst Chemical Co., Ltd.)
Manufactured by SI-300P) having a solid content concentration of 5% by weight as a sol (25 kg) is used as a seed, and the seed (seed) dispersion is adjusted to pH 12.5 with an alkaline aqueous solution, which is then heated at 95 ° C. for 30 minutes. It was stirred. 0.5 wt% sodium aluminate 37.5k in a solution containing this seed
g and 1.5 wt% water glass 37.5 kg each 7
Simultaneously added at 8.1 g / min over 8 hours. Then
After aging at 95 ° C. for 1 hour, it was cooled to room temperature. This sol was washed with 100 times distilled water using an ultrafiltration membrane and further concentrated to 15% by weight to obtain a sol in which silica-alumina fine particles were dispersed.

FIG. 1 shows a laser light scattering particle size distribution analyzer (manufactured by Hiac / Royco, NICOMP-370).
FIG. 4 is a particle diameter distribution chart of the sol obtained by measuring the average particle diameter (Dpc) of the fine particles is 0.37 μm and the particle diameter is 0.26.
The ratio in the range of up to 0.48 μm was 77.4%.

This sol was spray-dried at a temperature of 130 to 230 ° C. and then calcined at 500 ° C. for 2 hours to have an average particle size of 65.
Spherical inorganic oxide particles having a size of μm were obtained. 3 and 4 show
It is an electron micrograph of this spherical inorganic oxide particle.

1.35 g of the spherical inorganic oxide particles were
Disperse in 30 ml of 2 wt% polyphosphoric acid aqueous solution, and
After ultrasonic treatment at 9.5 K for 15 minutes, the particle size distribution was measured by the above-mentioned centrifugal particle size distribution measuring method, and the particle size distribution chart shown in FIG. 2 was obtained. The average particle diameter (Dpm) of the dispersed particles is 0.37 μm, and the particle diameter is 0.26 to
The ratio occupying the range of 0.48 μm is 77.1%,
Therefore, the value of Dpm / Dpc was 1.0.

Example 2 Silica sol having an average particle size of 180 nm (Catalyst Chemical Co., Ltd.)
Manufactured by SI-180P) having a solid concentration of 5% by weight as a sol (25 kg) is used as a seed, and the seed dispersion is adjusted to pH 12.5 with an alkaline aqueous solution.
Stir for 0 minutes. 0.5% by weight in a solution containing this seed
54.5 kg of sodium aluminate and 54.5 kg of 1.5 wt% water glass were simultaneously added at 113.5 g / min over 8 hours. Then, the mixture was aged at 95 ° C. for 1 hour and then cooled to room temperature. This sol was washed with 100 times distilled water using an ultrafiltration membrane and further concentrated to 15% by weight to obtain a sol in which silica-alumina fine particles were dispersed. The average particle diameter (Dpc) of silica-alumina fine particles in the sol was 0.23 μm, and the ratio of the particle diameter in the range of 0.16 to 0.30 μm was 68.2%.

This sol was spray-dried at a temperature of 130 to 230 ° C. and then calcined at 500 ° C. for 2 hours to give an average particle size of 68.
Spherical inorganic oxide particles having a size of μm were obtained. 1.35 g of these spherical inorganic oxide particles were added to a 0.2 wt% polyphosphoric acid aqueous solution 30 m.
After being dispersed in 1 l and subjected to ultrasonic treatment at a wavelength of 19.5K for 15 minutes, the particle size distribution was measured by the above centrifugal particle size distribution measuring method. The average particle size (Dpm) of the dispersed particles is 0.
At 41 μm, the ratio of the particle size in the range of 0.29 to 0.53 μm was 62.4%, and the value of Dpm / Dpc was 1.78.

Comparative Example Silica sol having an average particle size of 5 nm (manufactured by Catalysts & Chemicals Co., Ltd.,
SI-550) was used as a seed in 1 kg of a sol having a solid concentration of 0.1% by weight, and the seed dispersion was adjusted to pH 12.5 with an aqueous alkaline solution and stirred at 95 ° C. for 30 minutes. 200 kg of 0.5 wt% sodium aluminate and 1.5 wt% water glass in a solution containing this seed 2
00 kg were added simultaneously at 139 g / min each over 24 hours. Then, the mixture was aged at 95 ° C. for 1 hour and then cooled to room temperature. This sol was washed with 100 times distilled water using an ultrafiltration membrane and further concentrated to 15% by weight to obtain a sol in which silica-alumina fine particles were dispersed. The silica-alumina fine particles in the sol had an average particle diameter (Dpc) of 0.09 μm.
The ratio of the particles having a particle diameter of 0.06 to 0.12 μm was 48.6%.

This sol was spray-dried at a temperature of 130 to 230 ° C. and then calcined at 500 ° C. for 2 hours to give an average particle size of 65.
Spherical inorganic oxide particles having a size of μm were obtained. 1.35 g of these spherical inorganic oxide particles were added to a 0.2 wt% polyphosphoric acid aqueous solution 30 m.
After being dispersed in 1 l and subjected to ultrasonic treatment at a wavelength of 19.5K for 15 minutes, the particle size distribution was measured by the above centrifugal particle size distribution measuring method. The average particle size (Dpm) of the dispersed particles is 5.
The particle size was 30 μm, and the ratio of the particle size in the range of 3.71 to 6.89 μm was 25.4%. Therefore, Dpm /
The value of Dpc is 58.9, which shows that the inorganic oxide particles (mother particles) have poor dispersibility in the fine particles (child particles) constituting them.

[Brief description of drawings]

FIG. 1 is a particle diameter distribution chart of inorganic oxide fine particles (child particles) prepared in Example 1.

FIG. 2 Inorganic oxide particles (mother particles) prepared in Example 1
FIG. 3 is a particle diameter distribution diagram of dispersed particles obtained by dispersing the above in water.

FIG. 3 is an electron micrograph of inorganic oxide particles obtained in Example 1.

FIG. 4 is an electron micrograph of inorganic oxide particles obtained in Example 1.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yusaku Arima 13-2 Kitaminato-cho, Wakamatsu-ku, Kitakyushu, Fukuoka Prefecture Catalysis Kasei Kogyo Co., Ltd. Wakamatsu Factory

Claims (2)

[Claims] 1. An inorganic oxide particle (mother particle) formed by agglomeration of inorganic oxide fine particles (child particles), which is represented by the following formula [1]:
Inorganic oxide particles characterized by satisfying: (However,
In the formula, Dpc represents the average particle diameter (μm) of the inorganic oxide fine particles (child particles), and Dpm represents the average particle diameter (μm) of the dispersed particles when the inorganic oxide particles (mother particles) are dispersed in water. ) Represents. ) 1.0 ≤ Dpm / Dpc ≤ 2.0 ... [1] 2. The inorganic oxide fine particles (child particles) have an average particle size in the range of 0.1 to 1.0 μm, and the particle size distribution is in the range of the average particle size ± 30%. The proportion is 50% or more, and the inorganic oxide particles according to claim 1.