JP4041892B2 - Porous glass microparticles and method for producing the same - Google Patents

Description

  The present invention relates to porous glass microparticles mainly composed of silica, alumina, alkali metal and / or alkaline earth metal, and a method for producing the same. In particular, the present invention relates to a porous glass microparticle having a mesopore and a polyhedral shape such as a cube and a method for producing the same.

  Porous materials having mesopores (2 to 50 nm) defined by IUPAC are widely used for microfilters, catalysts, enzymes and other carriers, column fillers, catalyst carriers, cosmetics, resin fillers and the like. Many of the porous materials in such a meso region are amorphous compounds, such as silica gel, silica alumina, activated carbon, phase separation glass, clay interlayer crosslinked porous material, mesoporous silica, and non-silica mesoporous oxide. It is represented by organic porous bodies, such as an inorganic porous body, a cellophane, a vinylon fiber, and an ion exchange resin.

  Conventionally, the manufacturing method by the phase separation method or the sol-gel method is well-known as a manufacturing method of porous glass. In the phase separation method, a borosilicate glass is melted at a high temperature of 1000 ° C. or higher to form a glass, and then subjected to a heat treatment again to cause phase separation and to elute soluble components to produce a porous glass. By controlling the heat treatment, the size of the generated mesopores can be changed from several nm to several hundred nm. In the sol-gel method, an alkoxide such as alkoxysilane is hydrolyzed to gel, and then dried to produce porous glass. The porous glass obtained by this method generally has 5 to 20 nm mesopores and 0.5 to 5 μm macropores. The porous glass obtained by the above production method is a bulk body, and in order to produce fine particles of the porous glass using these, it is necessary to pulverize after the above steps, and the particle diameters are made uniform. In some cases, further classification is necessary.

  As a method for producing porous glass microparticles, 1) a method of producing a sol-gel method from water glass and metal alkoxide has been proposed (for example, see Patent Document 1). It was difficult to control the pore diameter uniformly and to the desired diameter. In addition, after 2) heat-treating the fine glass particles having a glass composition capable of phase separation to phase-separate, and then eluting the acid-soluble component, clear pores can be obtained by the method of producing porous glass microparticles. Porous glass microparticles having a uniform pore diameter and controlled to a desired diameter have been reported (for example, refer to Patent Document 2), but this method is performed after wet pulverizing glass as a raw material in advance. A process of burning the mixture dispersed in the flammable liquid is required, and the process is complicated and expensive.

In addition, a method of producing porous glass microparticles from crystalline aluminosilicate microparticles has been attempted, and glass microparticles are obtained by subjecting zeolite, which is a porous aluminosilicate microparticle, to acid treatment and heat treatment, respectively. Is reported (for example, see Non-Patent Documents 1 and 2), but the product is not porous. It has also been reported that substances having mesopores can be obtained by dealumination of zeolite, which is crystalline aluminosilicate microparticles (see, for example, Non-Patent Documents 3 to 4). The thing remains crystalline, and complete glass particles are not obtained.
JP 2000-128519 A JP-A-11-1003003 Cook et al., Environ. Sci. Technol., Vol. 16, p344, 1982 Kosanovi? and Sboti? , Microporous Materials, Vol.12, p261, 1997 Le Van Mao et al., J. Mater. Chem. Vol. 2, p595, 1992 Horikoshi et al., Chem. Soc. Japan, p398, 1989

  The present invention has been made in view of such a situation, and porous glass microparticles having silica, alumina, alkali metal and / or alkaline earth metal as main components and having a central pore diameter in the range of 1 to 50 nm and It is an object to provide a manufacturing method thereof.

  As a result of intensive studies to improve the above-mentioned problems, the present inventors have acid-treated a specific crystalline compound mainly composed of silica, alumina, alkali metal and / or alkaline earth metal oxide, It has been found that the above problems can be solved by hydrothermal treatment, and the present invention has been completed.

That is, this invention was solved by taking the structure shown by the following [1]-[14].
[1] An amorphous substance mainly composed of (A) silica, (B) alumina, (C) alkali metal and / or alkaline earth metal, having a central pore diameter in the range of 1 to 50 nm, Porous glass microparticles with sharp pore distribution.
[2] It is characterized by containing (A) 30 to 70% by mass of silica, (B) 30 to 60% by mass of alumina, and (C) 0 to 10% by mass of alkali metal and / or alkaline earth metal. [1] The porous glass microparticles according to [1].
[3] In powder X-ray diffraction using Cu Kα ray as an X-ray source, at least one amorphous halo figure is shown in a range of 15 ° to 35 ° in terms of 2θ value [1] or [1] 2]. The porous glass microparticle according to any one of 2).
[4] In powder X-ray diffraction using Cu Kα ray as an X-ray source, the value (% X-ray diffraction intensity / reference substance) in accordance with ASTM (American Society for Testing and Materials) D 3906 is 5% or less. The porous glass microparticle according to any one of [1] to [3], wherein
[5] The pore volume in the porous glass microparticles is 50 mm ³ / g or more in terms of pore volume at a pore diameter of 1 to 100 nm shown by the glass particle pore distribution curve, and 70% or more thereof The porous glass microparticle according to any one of [1] to [4], which is in a region within ± 2 nm of the central pore diameter.

Here, the reason for defining the pore volume in the porous glass microparticle based on the pore volume in the pore diameter of 1 to 100 nm shown by the glass particle pore distribution curve is that the starting material (crystalline aluminosilicate That is, the zeolite) includes pores other than 1 to 100 nm, the total pore volume satisfies 50 mm ³ / g or more, and the state may remain as it is after the subsequent treatment. Therefore, this is to make it clear that it is different from this. That is, it refers to the pore volume of the porous glass microparticles in the distribution of the specific pore diameter region of 1 to 100 nm, and does not refer to the pore volume including the pore diameter outside the pore diameter range.
[6] The porous glass microparticle according to any one of [1] to [5], wherein the porous glass microparticle has a particle size of 0.1 to 500 μm.
[7] The porous glass microparticle according to any one of [1] to [6], wherein the shape of the porous glass microparticle has a non-spherical polymorphic structure.
[8] The porous glass microparticle according to [7], wherein the non-spherical polymorphic structure has a cubic structure.
[9] The porous glass microparticle according to [7], wherein the non-spherical polymorphic structure is an octahedral structure.
[10] (I) Hydrothermal treatment of a mixture of silica and alumina source compound and alkali metal and / or alkaline earth metal compound in an aqueous solution, (II) acid treatment of the formed crystalline compound (III) The method for producing porous glass microparticles according to any one of [1] to [9], comprising a step of hydrothermally treating the obtained compound.
[11] The method for producing porous glass microparticles according to [10], wherein the hydrothermal treatment step (1) is performed in a temperature range of 50 to 500 ° C.
[12] The method for producing porous glass microparticles according to [10], wherein the acid treatment step (2) is performed under conditions of an acid concentration of less than 0.1 N and a treatment temperature of 100 ° C. or less. .
[13] The method for producing porous glass microparticles according to [10], wherein the hydrothermal treatment step (3) is performed under a temperature condition of 100 to 300 ° C.
[14] The product obtained in the hydrothermal treatment step (1) is a crystalline aluminosilicate, which is subsequently obtained by subjecting it to (2) an acid treatment step and (3) a hydrothermal treatment step. The method for producing porous glass microparticles according to any one of [1] to [9].

  The present invention relates to porous glass microparticles, and has an ultrafine central pore diameter in the range of 1 to 50 nm, and its distribution characteristic has a very sharp pore distribution. It is expected to function as a selective adsorbent and separation agent that are extremely efficient for gases, ions, organic molecules, and the like. In addition, it is expected to be used in various catalytic reactions, function as a catalyst carrier or catalyst, and exhibit excellent catalyst carrying performance and catalytic performance. Of course, the porous glass microparticles of the present invention are not limited to these uses. For example, the porous glass microparticles can be used for drugs, cosmetics, resin fillers, etc. It is expected to be used as a versatile useful and novel additive component that is inferior to conventional materials.

  Hereinafter, the present invention will be described in detail. The porous glass microparticles of the present invention preferably consist essentially of silica, alumina, alkali metal oxide and / or alkaline earth metal oxide. Here, “substantially” means that the case where other components are included to the extent of impurities is allowed.

  The porous glass microparticle of the present invention comprises (A) silica, (B) alumina, (C) alkali metal and / or alkaline earth metal, and the composition ratio thereof is (A) 30 to 70% by mass, (B). It is preferable that they are 30-60 mass% and (C) 0-10 mass%. More preferably, the composition ratio is (A) 40 to 60% by mass, (B) 40 to 60% by mass, and (C) 0 to 10% by mass. When the composition amount of the component (A) exceeds 70% by mass, it becomes difficult to form a central pore diameter of 1 to 50 nm because the crystal component having micropores in the porous glass microparticles increases. When the composition amount of the component A) is less than 30% by mass, the acid resistance is remarkably weak and the particle shape cannot be maintained.

  There is no restriction | limiting in particular in the silica source used for a raw material, and an alumina source. Those that are easy to react when both the silica source and the aluminum source are mixed are preferably used. The silica source is preferably sodium metasilicate, colloidal silica, fumed silica, tetraethyl orthosilicate, etc., and the alumina source is alumina. Sodium acid, boehmite, pseudoboehmite, aluminum isopropoxide and the like are preferable.

The alkali metal and alkaline earth metal contained in the porous glass microparticles of the present invention are not limited to those derived from raw materials or added by ion exchange reaction. Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium, and francium. Examples of the alkaline earth metal include beryllium, magnesium, calcium, strontium, barium, and radium. The porous glass microparticles of the present invention may contain two or more kinds of metal ions, and are characterized in that most of them are amorphous as measured by powder X-ray diffraction using Cu Kα rays. . Mostly amorphous means that it has at least one amorphous halo figure in the range of 15 ° to 35 ° in terms of 2θ value in powder X-ray diffraction using Cu Kα ray as an X-ray source. This means that there is no obvious crystalline peak.

In addition, a slight crystallinity peak may be observed in the amorphous halo figure depending on the starting material at the time of manufacture. In such a case, in the powder X-ray diffraction using Cu Kα ray as an X-ray source, 2θ The crystallinity peak intensity observed in the range of 15 ° to 35 ° in terms of the value should be 5% or less in terms of the ratio of the corresponding crystalline reference material to the crystallinity peak (% X-ray diffraction intensity / reference material). Specific% X-ray diffraction intensity / reference material is ASTM (American Society for Testing
and Materials) that is given by the following formula in accordance with D 3906 can be used.

(% X-ray diffraction intensity / reference substance) = (S _X ) / (S _R ) × 100
S _X : Integral reflection intensity of sample S _R : Integral reflection intensity of reference substance The number of crystallinity peaks used for calculation of integral reflection intensity is not particularly limited, but a range of 1 to 8 is preferable. Since the reflection peak intensity in the powder X-ray diffraction may vary depending on the water adsorption state and the like, careful attention must be paid to the condition adjustment and measurement conditions of the sample and reference substance.

  The porous glass microparticle of the present invention is characterized by being porous. The central pore diameter is preferably in the range of 1 to 50 nm, and more preferably in the range of 1 to 30 nm. If the central pore diameter exceeds 50 nm, the particle form may not be maintained, and if it is less than 1 nm, the adsorption / separation rate may be significantly reduced. The central pore diameter is represented by a pore diameter showing a maximum peak of a pore distribution curve obtained by a nitrogen adsorption method.

  The porous glass microparticles of the present invention preferably have a sharp pore distribution. As means for expressing that the pore distribution is sharp, the central pore diameter and the volume of pores in the region of the pore diameter of 1 to 100 nm in the pore distribution curve (hereinafter referred to as pore volume) are used. That is, in the porous glass microparticles according to the present invention, what percentage (%) of the pore volume is in a region within ± 2 nm of the center pore diameter of the pores existing in the range of 1 to 50 nm. Express if there is. The larger the ratio (%), the higher the concentration of pores in the vicinity of the central pore diameter, and the sharper the pore distribution. The pores of the porous glass microparticles of the present invention are characterized in that 70% or more of the pore volume is in a region within ± 2 nm of the central pore diameter. For this reason, the porous glass microparticles of the present invention have a high adsorption selectivity for organic molecules.

The pores of the porous glass microparticles of the present invention are pores extending from the aforementioned mesopores to a partial region of the micropores. The micropore mentioned here is a pore having a pore diameter centered on 0.5 to 2 nm proposed by IUPAC as described in the academic literature (see Non-Patent Document 5) before this application. Is intended. The pore size distribution and pore volume can be determined from the adsorption capacities of various probe molecules. In the present invention, the micropore volume is defined by the adsorption capacity of N ₂ which is the most commonly used probe. The measured value when N ₂ is used as a probe is generally similar to the value measured using Ar or O _2, which is similar to N ₂ in molecular size and is inactive.
Kondo Seiichi, Ishikawa Tatsuo and Abe Ikuo "Science of adsorption" Maruzen Co., Ltd., 1991, page 12 The average particle size of the porous glass microparticles of the present invention is preferably in the range of 0.1 to 500 µm. . More preferably, it is the range of 1-200 micrometers. When the average particle size is less than the above lower limit, the production may be difficult, and the filtration rate when used in a separation and removal device such as a filter may be significantly reduced. Moreover, when exceeding 500 micrometers, a moldability may be reduced in the secondary processing which combines with a polymeric material etc., or an external appearance defect may be caused. The measurement of the average particle diameter can be obtained by direct statistical processing from an image such as a laser diffraction particle size measuring apparatus or an electron microscope.

  In the measurement by the laser diffraction type particle size meter, there is no big difference between the diffraction behavior of the incident laser beam due to the aggregated particles and the diffraction behavior of the isolated primary particles. There is no distinction between the particle size or the size of the aggregated secondary particles. Therefore, the average particle size measured by the method is an average value reflecting the average particle size of secondary particles including the isolated primary particles that have not been aggregated in a broad sense, and is therefore used in combination with direct observation using an electron microscope or the like. It is preferable.

The porous glass microparticles of the present invention are characterized by having a polyhedral shape substantially characteristic of crystals. As the shape of the above-mentioned porous compound crystal microparticles, since the shape is not affected in the step of vitrifying the porous compound crystal microparticles described later, the porous shape of the target shape (for example, substantially cube shape) When producing glassy glass microparticles, it is preferable that the compound crystal microparticles have a similar shape.
The porous glass microparticles of the present invention are porous crystalline microparticles (hereinafter referred to as porous) obtained by hydrothermal treatment of a mixture of a compound serving as a silica or alumina source and an alkali metal and / or alkaline earth metal-containing compound. The crystal microparticles) are produced by acid treatment and further hydrothermal treatment. Here, the types of silica, alumina source, alkali metal and / or alkaline earth metal, their content, etc. are as described above.

(1) Step of obtaining porous crystal microparticles: As a method of obtaining the above porous crystal microparticles,
A method of hydrothermally treating a mixture of a compound serving as a silica or alumina source and an alkali metal and / or alkaline earth metal compound in an aqueous solution is employed. Usually, a method of heating an aqueous solution of a mixture of a compound serving as a silica or alumina source and an alkali metal and / or alkaline earth metal compound by applying an appropriate pressure vessel such as a Teflon (registered trademark) container or a gold tube is preferable. Used for The heating temperature in this case is preferably between 50 and 500 ° C.,
More preferably, it is between ˜250 ° C. If it is less than 50 ° C., the reaction may be insufficient, and if it exceeds 500 ° C., the amount of a crystal phase other than the target may increase. After the hydrothermal treatment, the support (solid) may be used together with the solution in the next step. Usually, the reaction product is separated from the liquid by filtration or the like, and depending on the case, it is appropriately washed with water, dried, or Then, after post-treatment such as firing and reduction treatment, it is used in the next step. In many cases, a method of simply using a dried product after filtration is simple and preferable.

  As the porous crystalline microparticles, crystalline aluminosilicate (common name: zeolite) can be used.

Zeolite is represented by the Natrolite Group represented by Natrolite, Gonnardite, Eddingtonite, etc., the Analsim Group represented by Analsim, Leucite, Yugawara Light, Gismondine, Poringite-K, Philipsite-Ca, etc. Gismondine Group, Chabazite-Ca, Elionite-Na, Hojasite-Na, etc. Chabazite Group, Mordenite, Ferrierite-Mg, Mordenite Group, such as Mutinaite, Hulandite- Naturally produced zeolites such as Ca, clinoptilolite-Na, Stillite-Ca, etc. Synthetic zeolites represented by L, X, Y, Na-P1, ZK-5, ZSM-11, etc. are mentioned, preferably synthetic zeolites with uniform particle size, more preferably silica-alumina mass ratio A, X, etc. have a small difference. If the difference between the mass ratios of silica and alumina is too large, vitrification may be insufficient in the process described later.

  (2) Acid treatment step: As the acid, various inorganic acids and organic acids are used. For example, orthoboric acid, metaboric acid, trimetaboric acid, hypoboric acid, carbonic acid, isocyanic acid, thunderic acid, orthosilicic acid, metasilicic acid, nitric acid, peroxonitric acid, nitrous acid, peroxonitrous acid, nitroxyl acid, hyponitrous acid , (Ortho) phosphoric acid, diphosphoric acid, triphosphoric acid, polyphosphoric acid, metaphosphoric acid, trimetaphosphoric acid, tetrametaphosphoric acid, peroxo (mono) phosphoric acid, peroxodiphosphoric acid, hypophosphoric acid, diphosphorus (III, V) Acid, phosphorous acid, diphosphorous acid, hypophosphorous acid, arsenic acid, arsenous acid, hexahydrooxoantimonic acid, sulfuric acid, disulfuric acid, peroxo (mono) sulfuric acid, peroxodisulfuric acid, thiosulfuric acid, two Thionic acid, sulfurous acid, disulfite, thiosulfuric acid, dithionic acid, sulfoxylic acid, polythionic acid, selenic acid, selenious acid, (ortho) telluric acid, chromic acid, dichromic acid, perchloric acid, chloric acid ( Acid), chlorous acid, hypochlorous acid, bromic acid, bromous acid, hypobromous acid, (ortho) periodic acid, iodic acid, hypoiodous acid, permanganic acid, manganic acid, pertechnetium, technetium Acids, inorganic acids such as perrhenic acid, formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, pivalic acid, lauric acid, myristic acid, palmitic acid, stearic acid, acrylic acid, propiolic acid, methacrylic acid, croton Acid, oleic acid, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, maleic acid, fumaric acid, benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, toluic acid, naphthoic acid, cinnamic acid, 2- It is possible to use an organic acid such as fluoric acid, nicotinic acid, and isonicotinic acid, and an aqueous solution of a compound that is water-soluble and the aqueous solution is acidic. Hydrochloric acid to form a sexual salt, sulfuric acid, nitric acid, phosphoric acid, peroxodisulfuric acid, dithionite, sulfamic acid, nitro acid, and the like formic acid, acetic acid, trichloroacetic acid, trifluoroacetic acid, sulfonic acid. These may use 2 or more types depending on the case.

  In order to carry out a homogeneous reaction, although it depends on the type of acid, it is preferably used in the form of a dilute aqueous solution, and is generally preferably less than 0.1 base of acid. If the concentration is too high, part of silica and alumina is dissolved, which may affect the pore structure and particle shape. Further, neutral salts may be added to these acids. Moreover, as reaction temperature with an acid, it is preferable that it is 0-100 degreeC. If the reaction temperature is too high, recrystallization may occur and glass may not be obtained.

The standard of the amount of acid used is 0.5 to 1.0 in terms of a molar ratio (A ₂ O / H, A: alkali metal, H: acid hydrogen ion) to the alkali metal oxide contained in the porous crystal microparticles. The range of is preferable. If the amount of acid used is small, vitrification may be insufficient or non-uniform. On the other hand, if the amount is too large, part of silica and alumina reacts with an excessive acid and dissolves, which may affect the pore structure and particle shape.

  (3) Hydrothermal treatment of the obtained compound: Thereafter, the porous glass microparticles of the present invention are obtained by hydrothermal treatment under suitable conditions.

  The hydrothermal treatment is usually preferably performed between 100 and 200 ° C, and more preferably between 120 and 180 ° C. The treatment time is generally selected from the range of 2 to 168 hours, preferably 12 to 48 hours. If the hydrothermal treatment temperature is too high or the treatment time is too long, recrystallization from glass may occur. If the treatment temperature is too low or the treatment time is too short, vitrification may be insufficient.

  However, if raw materials and conditions that do not cause such problems are selected, even low-temperature firing may be sufficient, and in particular, a porous material having desired physical properties at a stage after acid treatment without performing hydrothermal treatment. Glass microparticles can also be obtained.

The present invention will be described in more detail with reference to the following examples, which are disclosed as an aid for easily understanding the present invention, and are not limited to these examples.
The physical properties of the porous glass microparticles were evaluated as follows.
〔Evaluation item〕
When a composition scanning electron microscope [manufactured by JEOL Ltd.] JSM-5800LV was used for observation at 15 kV, the connected energy dispersive X-ray analyzer [manufactured by JEOL Ltd.] JED-2110 Was used to make measurements and determine the composition.
・ (% X-ray diffraction intensity / reference substance)
X-ray diffractometer [manufactured by Rigaku Denki Co., Ltd.] Using RINT2200, CuKα rays generated at 40 kV / 40 mA are used, the divergence slit angle is 1 degree, the divergence longitudinal limiting slit is 10 mm, the scattering slit is 1.25 mm, and the light receiving slit is 0 The measurement was performed under the conditions of 3 mm, a scanning speed of 2 degrees / minute, and a sampling width of 0.02 degrees. The amorphousness was calculated according to ASTM (American Society for Testing and Materials) D3906, using the porous crystal microparticles used in the acid treatment as a reference substance during the synthesis procedure. As the crystal reflection peak used for the calculation of (% X-ray diffraction intensity / reference substance), four peaks having a high intensity measured in the range of 15 ° to 35 ° / 2θ were used. For the reference material was integrated reflection intensity S _R seeking the sum of the number of counts excluding the background. Next, the peak strength of the porous glass fine particles finally obtained was obtained in the same manner, and this was designated as S _X , and the degree of amorphousness was estimated from the following formula.

(% X-ray diffraction intensity / reference substance) = (S _X ) / (S _R ) × 100
-Pore diameter distribution and pore volume The pore distribution and the pore volume were evaluated by creating a nitrogen adsorption isotherm using a pore distribution measuring apparatus (manufactured by Nippon Bell Co., Ltd.) BELSORP 28SA. The nitrogen adsorption isotherm was created as follows. That is, the sample was put in a glass sample tube, connected to a vacuum line, and degassed at 300 ° C. for about 12 hours to 10 ⁻⁴ mmHg. Immerse the sample tube in liquid nitrogen, introduce nitrogen gas at a predetermined pressure into the vacuum line, and after the pressure is stabilized, open the control valve of the sample tube, and after the pressure becomes constant, the equilibrium pressure (equilibrium pressure is 0 The same operation was repeated 22 to 28 points in a range of ˜760 mmHg). A nitrogen adsorption isotherm was created by plotting the nitrogen adsorption amount obtained from the equilibrium pressure and the pressure change. The pore distribution and pore volume in the present specification are determined from the nitrogen adsorption isotherm by the DH method (Dollimore and Heal. J. Appl. Chem., Vol. 14, p109, 1964).

As a means for expressing that the pore distribution is sharp, it is based on the method of Japanese Patent Application No. 11-356672, and the center fine diameter expressed by the pore diameter indicating the maximum peak of the pore distribution curve obtained by the above method is used. The pore diameter and pore volume (pore volume) in the pore diameter region of 1 to 100 nm in the pore distribution curve were used. That is, the porosity of the porous glass microparticles according to the present invention is such that the ratio (%) of the pore volume and the pore volume is the center pore diameter of the pores in the range of 1 to 50 nm. It is expressed by whether it is within the range of ± 2 nm. The larger the pore volume, the better the adsorption characteristics, and the larger the pore volume ratio (%) of the central pore diameter ± 2 nm, the higher the concentration of pores near the central pore diameter, and the sharper the pore distribution. Therefore, when this is subjected to adsorption operation and separation operation of various gases, ions, organic molecules, etc., it is suggested that excellent selectivity is exhibited in these operations, leading to an increase in operation efficiency.
・ Particle size Scanning electron microscope [manufactured by JEOL Ltd.] JSM-5800LV is used for observation at an acceleration voltage of 15 kV, and 100 representative particles are selected from the obtained photographic image, and particles are obtained using a scale. The Martin diameter of the image (Martin. Trans. Brit. Ceram. Soc., Vol. 23, p61, 1923) was measured to obtain the primary particle diameter, and the average value was taken as the average particle diameter.
-Particle form It evaluated by comparing with the particle form before performing the particle form after performing an acid treatment and hydrothermal treatment from the photographic image obtained by the measurement of the said scanning electron microscope.

◎: No change is observed at all ○: The shape is almost unchanged but the surface is changed ×: The shape is hardly changed (Example 1) As shown in FIG. A commercially available synthetic zeolite A-4 powder (manufactured by Wako Pure Chemical Industries, Ltd.) was used. A 100 ml beaker was charged with 0.3 g of 36 percent hydrochloric acid and 50 g of distilled water, and 0.5 g of the resulting porous crystal microparticles were added. Stir at room temperature for 10 minutes. After completion of the reaction, filtration was performed, and the obtained solid was washed with distilled water and then filtered again. Next, 50 g of distilled water was put in a fluororesin container, covered, and the whole was put in a stainless steel container and sealed, and heated in an oven at 150 ° C. for 24 hours. After the treatment, filtration and washing were repeated and dried at 30 ° C. for 24 hours to obtain a powder. The obtained sample was subjected to the physical property evaluation. The results are shown in Table 1 and FIG.

  (Example 2) Synthesis was performed in the same manner as in Example 1 except that a commercially available synthetic zeolite F-9 powder (manufactured by Wako Pure Chemical Industries, Ltd.) was used as the porous crystalline fine particles. The results of physical property evaluation of the obtained powder are shown in Table 1 and FIG.

  (Example 3) Commercially available synthetic zeolite A-4 powder (manufactured by Wako Pure Chemical Industries, Ltd.) was used as porous crystal microparticles, and 0.3 g of aluminum chloride was used instead of 0.3 g of hydrochloric acid in the acid treatment. The synthesis was performed in the same manner as in Example 1 except that hexahydrate was used. The results of physical property evaluation of the obtained powder are shown in Table 1 and FIG.

  (Comparative Example 1) Example 1 except that commercially available synthetic zeolite A-4 powder (manufactured by Wako Pure Chemical Industries, Ltd.) was used as the porous crystalline microparticles, and after acid treatment, hydrothermal treatment was not performed. The synthesis was carried out in the same manner as above. As a result of measuring the obtained powder with an X-ray diffractometer, although vitrification was observed, a slight crystalline peak was observed, and the amount of nitrogen gas adsorbed was measured. As a result, as shown in FIG. The clear peak which shows was not seen.

  The present invention provides porous glass microparticles having a characteristic pore distribution characteristic having a central pore diameter in the range of 1 to 50 nm and having a sharp pore distribution, It is expected to be used as a useful material in fields such as a catalyst or catalyst carrier, cosmetics, resin filler, etc., as well as functioning as a selective adsorbent / separator for various components such as ions and organic molecules. Is done.

Conceptual diagram of a cross section of a reaction vessel used for production of porous glass microparticles of the present invention The scanning electron microscope image of the synthetic zeolite A-4 used in Example 1. FIG. 3 is a graph showing a pore size distribution of porous glass microparticles synthesized in Example 1. The figure which shows the pore size distribution of the porous glass microparticle synthesize | combined in Example 2. FIG. FIG. 5 is a graph showing the pore size distribution of particles synthesized in Example 3. The figure which shows the pore size distribution of the particle | grains synthesize | combined in the comparative example 1.

Explanation of symbols

1 Fluororesin container 2 Distilled water 3 Zeolite after reacting with acid 4 Stainless steel container

Claims (11)

(A) Silica, (B) Alumina, (C) An amorphous substance mainly composed of alkali metal and / or alkaline earth metal, having a central pore diameter in the range of 1 to 50 nm and a pore volume.
The pore volume at a pore diameter of 1 to 100 nm shown by the glass particle pore distribution curve is 50 m.
m 3 ^{/ g} or more, Ru <br/> have more than 70% of the pore volume is distributed in the range of ± 2 nm of the median pore diameter porous glass microparticles. 2. (A) 30 to 70% by mass of silica, (B) 30 to 60% by mass of alumina, and (C) 0 to 10% by mass of alkali metal and / or alkaline earth metal. The porous glass microparticle described. 3. The powder X-ray diffraction using Cu Kα ray as an X-ray source exhibits at least one amorphous halo figure in a range of 15 ° to 35 ° as a 2θ value. Porous glass microparticles as described in 1. In powder X-ray diffraction using Cu Kα ray as an X-ray source, ASTM (American Society for
Testing and Materials) D 3906 (% X-ray diffraction intensity / reference substance) value is 5
The porous glass microparticle according to any one of claims 1 to 3, wherein the porous glass microparticle is 1% or less. The porous glass microparticle according to any one of claims 1 to 4 , wherein a particle diameter of the porous glass microparticle is 0.1 to 500 µm. The porous glass microparticle according to any one of claims 1 to 5 , wherein the shape of the porous glass microparticle has a non-spherical polymorphic structure. The porous glass microparticle according to claim 6 , wherein the non-spherical polymorphic structure has a cubic structure. The porous glass microparticle according to claim 6 , wherein the non-spherical polymorphic structure is an octahedral structure. (1) The step of acid-treating crystalline porous aluminosilicate , (2) The step of hydrothermally treating the obtained compound, The porous glass microparticle according to any one of claims 1 to 8 Production method. The acid treatment step (1), the acid concentration of 0.1 lower than the specified method for producing a porous glass fine particles according to claim 9, was characterized by performing the following conditions treatment temperature 100 ° C.. The method for producing porous glass microparticles according to claim 9, wherein the hydrothermal treatment step (2) is performed under a temperature condition of 100 to 300 ° C.