TW200815284A - Pelletized silica particles - Google Patents

Abstract

Pelletized silica particles characterized by a round shape and a monomodal particle size distribution are produced by dispersing silica particles into water, adding water to the dispersion, mixing with alkoxysilane, pouring the mixture into an organic solvent, filtering and washing the silica particles obtained. The pelletized silica particles can be used to produce glass monoliths.

Description

200815284 IX. Description of the Invention [Technical Fields of the Invention] The main system of the present invention is a granulated vermiculite particle, a method for its preparation and the use thereof. [Prior Art] How to manufacture a quartz (meteorite) glass powder system, The method comprises the steps of: hydrolyzing alkoxysilane at a specific pH to prepare a gel, pulverizing the gel, and calcining the powder after drying (Japanese Patent Application Publication (KOKA1) No. 67- 1 7 69 28 (1 987 )). It is also known how to use the following steps to produce synthetic quartz glass powder a) hydrolyzing alkoxy decane to form a gel thereof b) subdividing the gel, drying or sublimating the gel to form a powder, and c) calcining step b) Powder (US 5,516,350). The gel particle size before the calcination step was adjusted to a diameter of 60 to 900 μm. This data does not mention the particle size and fluidity characteristics of sintered quartz glass powder. Furthermore, it is also known how to manufacture a monolithic vermiculite glass article by the following steps: - oxidizing the oxidant in a solution to form a hydrolysis solution - adding an effective amount of fumed vermiculite to the lysate solution to form a sol solution - The sol solution is gelled to form a gel -4-200815284 - the gel is dried to form a xerogel and - the xerogel is sintered to form a glass to form a large monolithic fluorite glass article (US 4,801,318 This method cannot produce free-flowing synthetic quartz powder. Further, it is known how to prepare a spherical inorganic oxide-based material having a substantially unimodal distribution by the following steps: - forming a sol of at least one inorganic oxide by hydrolyzing a tetraalkoxy decane - adding to the sol a solvent immiscible with a sol - finely dispersing the resulting two-phase mixture into a dispersion of equal-diameter particles - growing the particles to a desired particle size by limiting coalescence and by adding a second solvent containing a gelling agent ( The dispersion of the coalesced droplets gels, and - removes the solvent. The spheroidal material exhibits a diameter between 1 nm and 1,000 nm in the case of a unimodal step. It can be used as a carrier for the polymerization and copolymerization of olefinically unsaturated compounds (EP 0537850 A1). In addition, it is known how to prepare globular vermiculite particles by the following steps: (A) preparing a colloidal vermiculite solution (B) in a colloidal vermiculite solution by hydrolyzing an alkoxylated oxime on an aqueous medium in the presence of a mineral acid or an organic acid. Possible dispersion into the smoky vermiculite (C) to mix the pure, vermiculite sol (step A) or the mixed vermiculite sol (step B) in an organic medium consisting of a monofunctional aliphatic alcohol R-OH or a mixture thereof (D) Emulsifying the mixture thus obtained (E) The gel obtained by heat-treating pure vermiculite sol-5-200815284 or mixed vermiculite sol (F) by contacting the previously obtained emulsion with an alkaline solution. The globular vermiculite particles showed a particle diameter (EP 0 65 3 3 78 A1 ) ranging from 10 to 100 μm. The transport, handling and storage of the powdered material is greatly affected by the fluidity and hardness of the particles, which therefore has a substantial commercial impact on the price and quality of the final product. In particular, the mixing efficiency of the powder is strongly influenced by problems such as non-uniform particle size distribution, particle cohesion, and agglomeration. The expression "free-flowing powder composition" as used throughout this specification means a powder (manufactured by rolling, micronizing, or the like) whose particles are composed of the above-defined composition and particles thereof. Will not stick to each other. The particle size of the powder particles is expressed by the particle diameter. In general, this particle size is determined by sieve analysis and is independent of particle shape. Conversely, a cohesive powder is one in which the cohesive forces between the particles are very important (in terms of strength). By definition, free-flowing powders do not contain fines. Conventional spray drying technique in which a heated gas is mixed with a nebulized (spray) liquid stream in a spray dryer in a vessel (drying chamber) to effect evaporation and to form a free-flowing dry powder having a controlled average particle size, for example Used by SDS Spray Drying Limited. With such a spray dryer, particles having an average size of 300 μm and a rather narrow particle size distribution can be produced. Another preferred method of accomplishing granulation of metal oxide particles is by coating with a chemical such as a polymer or oil or wax. In this case. The nature of pellets -6- 200815284 will change significantly, so it is rarely reported in the scientific literature. Even though many methods for granulating metal oxide particles have been reported in the literature, they are still affected by well-known problems in industrial-level operations such as mixing and transportation, that is, following conveyor belts or pneumatic conveyors. , such as: a) Segregation: mainly due to differences in particle size and, to a lesser extent, due to differences in particle density. In more detail, the forces that drive the condensation are: Van der Walls force, static electricity, liquid bridge, solid matter bridge and entanglement. b) Percolation, in which small-sized particles may gradually move under larger particles and thus cause separation of particles of different particle sizes. When referring to the purity of a particle, it is of great importance for vermiculite. In fact, today, for new high-end applications, such as: with others, internal, optical and microelectronic components, there is an increasing demand for meteorites with high purity levels. Unfortunately, due to the very high cost and very complicated manufacturing procedures, a large number of such products cannot be obtained in the market. SUMMARY OF THE INVENTION The main system of the present invention is a granulated vermiculite particle characterized by a circular and unimodal particle size distribution. The vermiculite particles according to the present invention have the vermiculite as a core, and the whole is surrounded by SiO 2 obtained by hydrolysis of liquid alkoxydecane. Particularly preferred is that the vermiculite may be SiO 2 such as fumed vermiculite or natural quartz. 200815284 The natural quartz may be a natural quartz derived from Norwegian Crystallites from the 〇丁八(3〇1^〇^11〇111〇丁八4 type). Compared with the granulated inorganic oxide particles of the present invention In a preferred feature, the core may be comprised of natural quartz and is surrounded by cerium oxide obtained by hydrolyzing a liquid alkoxy decane. The alkoxy decane may preferably be a tetraalkoxy decane such as tetraethoxy. The granulated inorganic oxide particles according to the present invention may have a surface area of more than 50 m 2 /g (m 2 /g ). The granulated inorganic oxide particles may have a particle size of at least 90% More than 100 microns. At least 90% of the pores may have a diameter between 5 Å and 1000 angstroms (A ngstr 〇m ). Further, the alkoxy decane may be mixed with a soluble salt to obtain a doped metal. Granulated inorganic oxide particles. The free-flowing number is based on a method developed by Degussa GmbH and published in Technical Bulletin fine Particles N 0.1 1 "Basic Characterisation of Aerosil Fumed silica", and more preferably from 5 to Within the scope of 2. A powder having poor flowability has a powder having an index of 値5 and a good flowability is evaluated as 1. Another object of the invention is to produce a particle having a circular and unimodal shape. A method of distributing granulated vermiculite particles. According to the invention, the inorganic chopping stone to be granulated is added to a container containing acidic water under stirring, when the dispersion is remarkably homogeneous and there is no agglomeration A liquid alkoxylated decane such as tetramethoxy decane and/or tetraethoxy decane is slowly added to the mixture. The temperature is increased as a result of the exothermic reaction. Then the dispersion thus obtained is -8-200815284 Using, for example, the conduit is slowly transferred into a container which is filled with an organic solvent or eucalyptus oil which is kept under vigorous agitation and previously mixed with the ammonia derivative. The droplets of the vermiculite dispersed in contact with the alkaline organic solution are formed. Colloidal particles, which are collected at the bottom of the reactor and then transferred to another container with alcohol and/or esters, such as with others, dioxane, propanol, acetone, ethanol The pure ethyl acetate is washed and finally the particles are washed with acetone. The organic solvent or the eucalyptus oil is then used for further operations. The particles are then sieved and then the solvent is extracted under supercritical or slightly subcritical conditions. Alternatively, the solvent can be removed by controlled drying under controlled conditions (% moisture and T). The dried particles are then calcined with oxygen at elevated temperature for at least one hour to eliminate traces from the vermiculite particles. More specifically, the present invention relates to a process for producing vermiculite particles from a powder having a broad particle size distribution. Granulation can be obtained by using a sol-gel technique, which is described in part in EP 0 5 3 7 850 A1. In the preferred body of the process of the invention, the following features are included: At room temperature, the acid is added to the water in the vessel until an acidic pH (2) is reached. The vermiculite powder was then added very slowly with vigorous stirring and then a liquid alkoxylated ruthenium such as TEOS (Dynasil A, available from DEGUSSA AG) was added. The temperature rises several degrees as a result of the exothermic hydrolysis reaction. The mixture was then kept under stirring for at least 20 minutes. After vigorous stirring, the solution was injected into a container containing an organic solvent using a catheter. The pH is then increased via the addition of an amine such as the Primene class supplied by Rohm and Haas until a very basic condition of -9-200815284 is produced; for example, a pH in a 1% aqueous solution. The temperature is further increased. The particles are then continuously withdrawn from the reaction batch and the resulting particles are washed extensively with water to remove residual solvent. Thereafter, the thus obtained material was calcined in a shaft furnace at 600 ° C and 150 ° C for 2 hours to remove residual solvent. At least 90% of the treated particles have a size greater than 1 〇〇 microns. This granulation was obtained using tetraethoxydecane as a granulating agent. The granulation of natural quartz powder is slightly different. The acid is added to the water in the vessel at room temperature until a very acidic pH (2) is reached. A liquid alkoxylated ruthenium such as TEOS (Dynasil A, available from DEGUSSA AG) was added to the mixture with stirring, and the temperature rose by several degrees as a result of the exothermic hydrolysis reaction. Thereafter, natural quartz powder is added to the mixture and then maintained under stirring for at least 20 minutes. After vigorous stirring, the solution was poured into a container containing an organic solvent maintained under vigorous stirring. The pH is then increased via the addition of an amine such as the Primene class supplied by Rohm and Haas until a very basic condition is produced, such as a pH in a 1% aqueous solution. The temperature is further increased. The particles are then continuously withdrawn from the reaction batch and the resulting particles are washed with a large amount of water to remove residual solvent. Thereafter, the thus obtained material was calcined in a vertical furnace at 600 ° C and 150 ° C for 6 hours to remove residual solvent. In other places, this patent relates to free-flowing powder compositions comprising hydrolyzed alkoxylated oximes such as TEOS, and metal oxides and/or mixtures thereof. The particles are characterized by the fact that since the granulating agent is capable of impregnating the inorganic oxide particles of -10-200815284, the granulating agent (hydrolyzed alkoxylated lanthanum such as TEOS) is substantially continuous with the core material. Phase. The glassy particles obtained by this method according to the invention are identified as follows: fluidity, microporosity and particle size distribution. Alternatively, when the inorganic oxide is vermiculite or vermiculite quartz, the process of the invention can be used to obtain a higher final product purity than the starting particles. The purity is increased approximately directly relative to the amount of granulating agent used, such as alkoxylated molybdenum, such as TEOS. The initial pH of the aqueous solution of the inorganic oxide particles may be in the range of 1 to 4. The liquid alkoxydecane may be tetramethoxydecane (CH30) 4Si and/or tetraethoxydecane (CH3-CH2-0) 4Si. The organic solvent may be a non-polar organic solvent having a dielectric constant of less than 60 at 20 °C. The salt to be added to the doped vermiculite particles may be 'others', aluminum acetate, aluminum sulfate, ammonium aluminum sulfate, lead acetate, boric acid, ammonium fluoride sulfate, ammonium fluoride. The non-polar organic solvent may be a liquid alkane such as hexane, heptane, octane, decane; and an alcohol such as propanol, butanol, pentanol, hexanol, heptanol, octanol, decyl alcohol And sterols; and aromatic compounds such as toluene, benzene, nitrobenzene, chlorobenzene, dichlorobenzene, porphyrin, decalin and/or mixtures thereof. In addition, as with organic solvents, eucalyptus oil can also be used. The eucalyptus oil can be a polydimethyl siloxane fluid such as Dimethicone from Wacker Chemie AG under the brand name Wacker AK 50. 200815284 The ammonia derivative of the organic base may be a cyclohexylamine or a tertiary alkylamine. The pH after addition of the organic base is expressed as a 10% aqueous solution, and may range from 8 to 13 and more preferably from 10 to 11. The calcination temperature can be between 300 and 700 ° C, more preferably between 300 and 600 ° C. The granulated vermiculite particles have a round shape and they are almost free of fine powder characteristics. Analysis of the granulated vermiculite particles shows that the process of the invention can be used to obtain a unimodal distribution. The microporosity and surface area of the material were determined by a method according to DIN 66131 using an ASAP 2010 instrument from Micromeritics, and the measurement was carried out in liquid nitrogen. Prior to analysis, the material was degassed at 300 °C for 4 hours (P = 1χ1 (Γ6). The flowability was determined by a very simple but meaningful measurement method using a viscosity-like container similar to an hourglass. The powder with good fluidity can flow out of the glass container through a small discharge hole (see Degussa Aerosil Silanes Technical Bulletin Fine particle, page 56-5, page 20 05). When the powder / nine particles can only flow very large In the case of a container, it can be regarded as grade 5, and when the powder/nine can flow very easily through even very fine containers, it has a grade of 1. The solvent used to disperse the colloidal particles during titration with an ammonia derivative is non- Polarity, having a dielectric constant not higher than 60. The list of solvents for testing includes: alkanes such as hexane, heptane, octane, decane and alcohols such as: propanol, butanol, pentanol, hexanol, Heptanol, octanol, decyl alcohol, decyl alcohol; and aromaticated -12-200815284 compounds such as toluene, benzene, nitrobenzene, chlorobenzene, dichlorobenzene, quinoline and decalin granulated vermiculite particles The purity industry has been tested by IC PM AS. The granulated vermiculite particles of the present invention significantly increase the transport yield of the material by reducing the amount of fine particles and narrowing the particle size distribution. [Embodiment] Example 1: 37% by weight at room temperature (19 ° C) (Gew·-%) Concentration of hydrochloric acid was added to 900 ml of water in a 4 liter vessel until pH 2 was reached. Then, 65 g of smoky vermiculite supplied by Degussa to be granulated was added very slowly with stirring, Aero Si 1 EG50. When the dispersion is clear and uniform without agglomeration, 650 g of TEOS (Dynasil 40 from DEGUSSA AG) is added very slowly to the mixture. As a result of the exothermic hydrolysis, the temperature can rise up to 24 °. C. After vigorously stirring for 1 hour, the solution was slowly pipetted into a 15 liter vessel containing 15 liters of eucalyptus oil (Wacker AK 50 from Wacker Chemie) and a tertiary amine Primene JM-T (using a catheter). Among the mixtures provided by Rohm and Haas, this gives a pH of 11 (expressed as a 10% aqueous solution). The temperature is further increased to 31 ° C. The emulsion containing the gel particles is then filtered and then with water / The acetone solution washes the particles so obtained in large quantities to go Residual eucalyptus oil. The material thus obtained was then placed in a shaft furnace and calcined at 60 (TC for 8 hours to remove residual solvent. -13 - 200815284 Characteristic analysis Particle size: characteristic averaging diameter of the material having a unimodal particle size distribution of 43 The 0 micron starting material has a size of 3.7 micron porosity: a pore diameter of 60 angstroms and a surface area of 99 square meters per gram which is almost twice the surface area of the starting material. Elemental analysis: Impurities in the starting material (ppm)

Na 1 · 6 K 0· 3 Li 3. 8 A1 2 3 Ca 0. 5 Fe 0. 6 Ti 2. 4 Co 0· 01 Cu 0. 01 Cr 0· 02 Impurity in the final material (ppm)

Na 0.6 K 0.05 Li 3.0 A1 1 2 -14- 200815284

Ca 0.03 Fe 0.01 . Ti 1.0 Co < 0.01 Cu < 0.01 Cr < 0.01

Granulation not only greatly improves the size of the particles, but also greatly improves the dispersion (monomodal distribution) because the purity of the final material is much better than the purity of the starting particles. Fluidity: The grade of the starting material is 5, while the grade of granulated vermiculite has a grade of 2, which means that the granulation procedure has improved the free-flowing behavior. Example 2

37% by weight (Gew·-%) of hydrochloric acid was added to 900 ml of water in a 4 liter vessel at room temperature (19 ° C) until pH 2 was reached. Then, 650 g of tetraethoxydecane (TEOS) (Dynasil 40, available from DEGUSSA AG) was added very slowly to the mixture with vigorous stirring. After stirring for 20 minutes, 650 g of natural quartz to be granulated was slowly added, and as a result of the exothermic hydrolysis reaction, the temperature was raised to 221 . After 1 hour of vigorous stirring, the solution was dropped into a 22 liter vessel containing 15 liters of eucalyptus oil (Wacker AK50, available from Wacker Chemie). The pH was then increased via the addition of a tertiary amine · Primene JM-T (supplied by Rohm and Haas) until pH 1 1 (10% aqueous solution) was reached, which corresponds to the weight/weight Primene in the eucalyptus oil. The temperature is further increased to -15-200815284 3 1 °C. The emulsion containing the gel particles is then considered and then the particles thus obtained are washed with a large amount of water to remove residual eucalyptus oil. The material thus obtained was then placed in a shaft furnace and calcined at 600 ° C for 8 hours to remove residual solvent. Characteristic analysis: Particle size: The material has a unimodal particle size distribution with a characteristic average diameter of 500 microns. The starting material has a size of 5 · 7 μm and a porosity of 74 m 2 / gram, which is almost undetectable compared to the area. The same element was measured for impurities (ppm) in the starting material: Na 1.9 K 0.6 Li 3.8 A1 36.0 C a 1.0 Fe 0.4 Ti 3.2 Co < 0.001 C u 00〇9 Cr 0·〇3 In the final material before calcination Impurities (ppm): -16- 200815284

Na 2.0 K 0.7 8 Li 3.1 A1 20 Ca 1.7 Fe 0.5 1 Ti 3.2 Co < 0.0 1 Cu < 0.015 Cr 0.43

Impurities in the final material after calcination (ppm)

Na 0.9 K 0.59 Li 2.01 A1 2 1.0 Ca 3.40 Fe 0.01 Ti 2.9 Co < 0.0 1 Cu < 0.01 Cr < 0.02 Granulation not only greatly improves the particle size, but also greatly improves the dispersion (unimodal distribution) ), because the purity of the final material is much better than the purity of the starting particles. -17- 200815284 Fluidity: The grade of the starting material is 5, while the granulated natural quartz has a grade of 4 before the calcination procedure and a grade between 2 and 3 after the satin burning procedure, which means that the granulation procedure has Improve free flow behavior. Example 3:

37% by weight (Gew·-%) of hydrochloric acid was added to 900 ml of water in a 4 liter vessel at room temperature (19 ° C) until pH 4 was reached. Then, under vigorous stirring, 85 g of NH4F was dissolved and stirring was continued, and 585 g of fluorinated vermiculite to be granulated, Aerosil EG50) (Dynasil 40, available from DEGUSSA AG) supplied by Degussa, was added very slowly. When the dispersion was clear and uniform and there was no agglomeration, 650 grams of TEOS (Dynasil 40 from DEGUSSA A G ) was added very slowly to the mixture. As a result of the exothermic hydrolysis reaction, the temperature was raised to 24 °C. After vigorously stirring the solution for 1 hour, the solution was very slowly and dripped into a 22 liter vessel containing 15 liters of eucalyptus oil (Wacker AK50, available from Wacker Chemie). The pH of the sand oil bath was then increased via the addition of a tertiary amine · Primene JM-T (supplied by Rohm and Haas) until a pH of 1 1 (10% aqueous solution) was reached, which corresponds to 10% by weight in the eucalyptus oil. Weight Primene. The temperature was further raised to 31 °C. Then, the emulsion containing the gel particles was considered and then the particles thus obtained were washed in a large amount with an acetone/water solution to remove the residual sand oil. The material thus obtained was then placed in a shaft furnace and calcined at 600 ° C for 8 hours to remove residual solvent. Characteristic analysis: -18- 200815284 Particle size: The material has the characteristics of unimodal particle size distribution. The average diameter is 300 microns. The starting material size is 5.7 microns.

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Claims (1)

200815284, X. Patent application scope ^ 1 · A granulated vermiculite particle characterized by a circular and unimodal particle size distribution. 2. A method for producing granulated vermiculite particles according to item 1 of the patent application, characterized in that the vermiculite particles are dispersed in water of an acidic pH under stirring, followed by the addition of liquid alkoxylated decane, and the thus obtained dispersion The liquid is transferred to a vessel containing the organic solvent under vigorous stirring, after which the pH is raised via the addition of an inorganic base ammonia derivative, and the resulting gel particles are washed with an alcohol and then with a mixture of alcohol and water, and then The particles are filtered and then calcined at elevated temperature for at least one hour to remove traces of solvent from the inorganic oxide particles. 3. The method according to item 2 of the patent application, wherein the vermiculite is vermiculite quartz. 4. The method of claim 2, wherein the initial pH of the aqueous solution containing vermiculite particles is in the range of 1 to 4. φ 5. The method of claim 2, wherein the vermiculite is a smoky vermiculite. 6. The method of claim 2, wherein the liquid alkoxydecane is tetramethoxynonane and/or tetraethoxydecane. 7. The method of claim 2, wherein the organic solvent is a non-polar organic solvent and has a dielectric constant of less than 60 at 201. 8. The method of claim 2, wherein the aqueous solution contains a soluble salt which is used as the last nine dopants. 9 · According to the method of claim 7, wherein the non-polar-20-200815284 organic glutinous agent is a liquid hospital such as a hospital, a Gengyuan, a Xinyuan, a brothel or a sand oil and an alcohol such as: propanol, butyl Alcohol, pentanol, hexanol, heptanol, octanol, decyl alcohol, decyl alcohol and aromatic compounds such as toluene, benzene, nitrobenzene, chlorobenzene, dichlorobenzene, quinoline and decahydronaphthalene and/or their mixture. The method of claim 2, wherein the ammonia derivative is a cyclohexylamine or a tertiary alkylamine. 1 1. The method of claim 2, wherein the pH after the addition of the φ machine base is in the range of from 8 to 12, more preferably from 1 Torr to 12. 1 2. The method according to item 2 of the patent application, wherein the calcination temperature is between 3〇〇 and 8〇〇1, more preferably between 3〇〇 and 6〇〇°0, 〇1 3 A method for producing granulated vermiculite particles according to item 1 of the patent application, characterized in that a liquid alkoxylated decane is added to the acidic pH water under stirring, and then added to the solution under vigorous stirring. Day φ quartz powder; the dispersion thus obtained is transferred to a vessel containing an organic solvent under vigorous stirring, after which the pH is raised by adding an inorganic alkali ammonia derivative, and the obtained gel particles are treated with an alcohol and then with an alcohol The mixture of water is washed, and then the particles are filtered and calcined at a high temperature for at least one hour to remove a trace amount of the solvent from the inorganic oxide particles. 1 4. The method according to claim 13 of the patent application, wherein the initial pH of the aqueous solution containing vermiculite particles is in the range of 1 to 4 ° 1 5 . According to the method of claim 13 ' The liquid alkoxy decane is tetramethoxy decane and/or tetraethoxy@ ^ ° -21 - 200815284, 16. The method according to claim 13 wherein the organic solvent is non-polar organic The solvent has a dielectric constant of less than 60 at 20 ° C. The method according to claim 13 wherein the aqueous solution contains a soluble salt which is used as the last nine dopants. 18. The method according to claim 16, wherein the non-polar organic solvent is a liquid alkane such as hexane, heptane, octane, decane or eucalyptus oil φ and an alcohol such as propanol, butanol, pentanol or hexanol , heptanol, octanol, decyl alcohol, decyl alcohol and aromatic compounds such as toluene, benzene, nitrobenzene, chlorobenzene, dichlorobenzene, quinoline and decahydronaphthalene and/or mixtures thereof. The method according to claim 13 wherein the ammonia derivative is a cyclohexylamine or a tertiary alkylamine. 20. The method according to claim 13, wherein the pH after the addition of the organic base is in the range of from 8 to 12, more preferably from 1 to 12. #2 1 . The method according to claim 13 wherein the calcination temperature is between 300 and 800 ° C, more preferably between 300 and 600 ° C. 0 -22- 200815284 VII. Designated representative map: (1) The designated representative of the case is: None (2) The representative symbol of the representative figure is a simple description: None 8. If there is a chemical formula in this case, please reveal the chemical formula that best shows the characteristics of the invention.