WO2008035538A1 - Procédé de fabrication de particules de carbonate de métal alcalino-terreux et particules de carbonate de métal alcalino-terreux - Google Patents
Procédé de fabrication de particules de carbonate de métal alcalino-terreux et particules de carbonate de métal alcalino-terreux Download PDFInfo
- Publication number
- WO2008035538A1 WO2008035538A1 PCT/JP2007/066447 JP2007066447W WO2008035538A1 WO 2008035538 A1 WO2008035538 A1 WO 2008035538A1 JP 2007066447 W JP2007066447 W JP 2007066447W WO 2008035538 A1 WO2008035538 A1 WO 2008035538A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- earth metal
- alkaline earth
- metal carbonate
- particles
- particle
- Prior art date
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/18—Carbonates
- C01F11/186—Strontium or barium carbonate
- C01F11/187—Strontium carbonate
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/18—Carbonates
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01F—COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS
- C01F11/00—Compounds of calcium, strontium, or barium
- C01F11/18—Carbonates
- C01F11/186—Strontium or barium carbonate
- C01F11/188—Barium carbonate
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/51—Particles with a specific particle size distribution
- C01P2004/52—Particles with a specific particle size distribution highly monodisperse size distribution
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/54—Particles characterised by their aspect ratio, i.e. the ratio of sizes in the longest to the shortest dimension
Definitions
- the present invention relates to a method for producing alkaline earth metal carbonate particles having an acicular shape with improved particle size distribution and alkaline earth metal carbonate particles.
- Alkaline earth metal carbonates such as calcium carbonate, strontium carbonate, and barium carbonate are used as additives for paper, rubber, resin, plastic, paint, cosmetics, pharmaceuticals, and dielectric ceramic materials and high-temperature superconductor materials. It is used in a wide range of industrial fields as a raw material for these materials and as an inorganic dope material for optical films.
- Alkaline earth metal carbonates are known to have different functions and properties depending on their physical properties.
- alkaline earth metal carbonates can be used to produce paints with low gloss and excellent wet ink fillability.
- Spindle-like calcium carbonate is suitable for use, and acicular calcium carbonate is suitable for the production of paints with high glossiness, opacity, ink inking properties, and ink setting!
- strontium carbonate is used as a raw material for producing strontium titanate, it has been reported that electrical characteristics are improved by using particles having an average particle size of 0.8 in or less.
- small particles of m order or less are required in order not to impair transparency.
- a method for producing alkaline earth metal carbonate particles includes a “liquid-at-a-time” method in which carbon dioxide gas is reacted with a solution containing an alkaline earth metal ion, which is referred to as a carbon dioxide gas method.
- a carbon dioxide gas method Prepared by reacting a solution containing earth metal ions with a solution containing carbonate ions Broadly divided into “liquid” methods.
- the “liquid-at-a-time” method is mainly used industrially, and alkaline earth metal hydroxides such as Ca (OH), Sr are used as solutions containing alkali earth metal ions. (OH) and Ba (OH) are often used, but these hydroxides are usually used as slurries because of their low solubility.
- a method of producing 1 to 2 m of columnar calcium carbonate in three stages (see, for example, Patent Document 1), and water-soluble monosaccharides and oligosaccharides are hydrolyzed before the carbonation reaction reaches 30%.
- a method of adding 1 to 2 m of spindle-shaped calcium carbonate added to the calcium slurry (see, for example, Patent Document 2), the temperature of the strontium hydroxide slurry and the introduction rate of carbon dioxide gas are defined.
- a method for producing ac needle-shaped strontium carbonate (for example, see Patent Document 3) has been proposed.
- a metal ion source containing at least one selected from strontium, calcium, norlium, zinc, and lead and a carbonate source are reacted in a liquid by a double jet method to form needle-like and rod-like carbonates.
- a method using a “liquid-liquid” method such as a manufacturing method (for example, see Patent Document 6) has been proposed!
- a carbonic acid source is reacted in a liquid of a metal ion source containing at least one selected from the ionic forces of strontium, calcium, norlium, zinc, and lead.
- a production method has been proposed that includes a step of increasing the number of particles and a step of increasing the volume of a particle, and reacting by controlling the acceleration rate and time of the carbonic acid source, and having a shape with an aspect ratio greater than 1. (For example, see Patent Document 7).
- this method uses a single jet method as an ion source addition method, it is a manufacturing method that includes the problem described in item i), and metal ions stored in a reaction vessel. Since the carbonic acid source was added to the source, the problem described in item iii) was unavoidable, and it was insufficient as a technique for improving the deterioration of the particle size distribution.
- Alkaline earth metal carbonates produced by the “liquid at once” method are inherently very strong in cohesion between primary particles (nuclear particles), and many primary particles are aggregated. It forms large secondary particles (coarse aggregates of primary particles), and this secondary particle slurry cannot be peptized to the state of primary particles even if it is vigorously stirred for a long time. It is said that.
- alkaline earth metal carbonate particles formed as aggregates are A powerful grinding method using a ball mill, sand grinder mill, or the like is used.
- fine glass beads may be used as a grinding medium.
- the surface of these glass beads As a result, a large number of coarse glass pieces of several meters or more may be mixed in the alkaline earth metal carbonate particles after the dispersion treatment, which is preferable and difficult! is the current situation.
- Patent Document 1 Japanese Patent Publication No. 55-51852
- Patent Document 2 JP 2001-139328 Koyuki
- Patent Document 3 Japanese Unexamined Patent Publication No. 2006-124199
- Patent Document 4 Japanese Patent Application Laid-Open No. 59-203728
- Patent Document 5 JP-A-5-155615
- Patent Document 6 Japanese Unexamined Patent Publication No. 2006-21988
- Patent Document 7 Japanese Unexamined Patent Application Publication No. 2006-169038
- the present invention has been made in view of the above problems, and its purpose is to control the morphology and cohesiveness of alkaline earth metal carbonate particles, and to provide a particle size distribution having a needle-like morphology.
- An object of the present invention is to provide an improved method for producing alkaline earth metal carbonate particles and an alkaline earth metal carbonate particle produced by the production method.
- the present inventors have separated the nucleation step and the particle growth step of alkaline earth metal carbonate particles, and provided optimum conditions for each step.
- the needle-like form includes a columnar form and a bar-like form.
- an alkaline earth metal salt solution and a carbonate solution are reacted to form needle-shaped particles having an average aspect ratio of 2 or more.
- a method for producing alkaline earth metal carbonate particles comprising: a particle growth step after the nucleation step, and performing a dispersion operation after the nucleation step is completed. Method.
- the above-mentioned aggregation inhibitor is a water-soluble polymer having an amide group
- Average values of major axis and minor axis diameter of the alkaline earth metal carbonate particles at the end of the nucleation step are a and b, respectively, and the alkaline earth metal carbonate at the end of the particle growth step.
- V (a-a) / (bb)
- At least one part of the nucleation step or the particle growth step is performed under a condition in which the liquid in the reaction vessel is in excess of alkaline earth metal ions.
- Rate of addition of alkaline earth metal salt solution and carbonate solution in the nucleation step 0.1 mol / min or more per mol of alkaline earth metal carbonate formed in the nucleation step 15.
- the molar ratio of the alkaline earth metal carbonate formed in the nucleation step to the alkaline earth metal carbonate particles at the end of the particle growth step is 50 mol% or less.
- the nucleation step in the production process of alkaline earth metal carbonate particles is a process for generating nuclei particles, and the particle growth step is almost accompanied by the generation of new nuclei particles. Means the process of growing particles without
- the number of particles increases in the nucleation step, and the number of particles does not increase substantially in the particle growth step! / (The number of particles may decrease when subjected to Ostwald ripening). Therefore, both processes can be distinguished by the presence or absence of new nuclear particles.
- the fact that the number of particles does not substantially increase means that the number of particles at the end of the particle growth process is within 125% at the start of the particle growth process (or at the end of the ripening process when the ripening process is included). To do.
- the alkaline earth metal carbonate according to the present invention can be formed by reacting an alkaline earth metal ion and a carbonate ion.
- alkaline earth metal ion source for example, Ca 2 +, Sr 2+, Ba 2+, is Ra 2+, As the specific compound for the case of Ca 2+, CaCl, Ca (NO),
- Examples of compounds that can be used as the carbonate ion source include Na CO, NaHCO, K CO, and KH.
- Alkaline earth metal carbonate particles generated by the reaction begin to grow immediately after the generation of the core particles, and therefore grow faster as the core particles are generated earlier and more difficult to grow as the core particles are generated soon after.
- particle growth during the nucleation step is not preferable because it increases the particle size distribution of the nucleus particles and causes deterioration of the particle size distribution after the completion of particle growth.
- the broadening of the particle size distribution of the nuclei that occurs during the nucleation step largely depends on the nucleation time and the nucleation temperature. That is, if the time of the nucleation process is long, the particle size distribution deteriorates due to the early growth of the nucleation particles, and the temperature of the nucleation process is high! The particle size difference between the generated core particles and the core particles generated later is amplified.
- the time of the nucleation step can be arbitrarily set, but it is preferable to end within 1800 seconds in order to prevent the deterioration of the particle size distribution, and within 300 seconds is more preferable 120 seconds. Within is more preferable.
- the temperature of the nucleation step can be arbitrarily set, but in order to suppress the growth of nuclei particles during the nucleation step, it is preferable to perform at a temperature as low as possible. It is preferably carried out between 40 ° C. At lower temperatures, the liquid in the reaction vessel freezes, and special equipment is required for temperature control, increasing production costs.
- Alkaline earth metal carbonate particles can be produced by introducing carbon dioxide gas into a solution of an alkaline earth metal salt called "carbon dioxide gas method” and reacting it ("liquid at once” method) Solutions containing alkaline earth metal salts and carbonate ions, such as the jet and double jet methods There is a method of reacting a liquid (“liquid-liquid” method). In the present invention, it is preferable to use a double jet method for nucleation and particle growth! ! /
- the double jet method By applying the double jet method to the nucleation process, it is possible to increase the number of nuclei generated per unit time by increasing the degree of supersaturation in the stirring and mixing device. Thus, improvement of distribution deterioration in the nucleation process can be expected.
- the double jet method to the particle growth process, it is possible to control the degree of supersaturation in the stirring and mixing apparatus with high accuracy, so that control of the particle shape and improvement of the distribution can be expected.
- the carbon dioxide method can be applied to a part of the particle growth process.
- a slurry of an alkaline earth metal hydroxide is added to the reaction solution after completion of the nucleation step and the aging step to form a slurry, and carbon dioxide gas is introduced into the slurry to form particles.
- the growth method can be mentioned. Since this method uses an alkaline earth metal salt slurry, it is possible to effectively use a high-concentration solution, which is effective in improving productivity.
- the double jet method according to the present invention is a method in which two kinds of solutions are dropped or jetted onto the liquid surface of the liquid in the reaction vessel or into the liquid, respectively, using an appropriate liquid delivery device or the like, if necessary.
- This is a method of reacting in the liquid in the container by pouring, and in the present invention, it can be carried out by using an alkaline earth metal salt solution and a carbonate solution as additive liquids.
- the solvent of the solution containing the aggregation inhibitor, the alkaline earth metal salt solution, and the carbonate solution is substantially water.
- the solvent is substantially water means that the content of a solvent other than water is 10% by volume or less.
- a solvent other than water, particularly an organic solvent is contained in an amount of 10% by volume or more, there is a concern that the particle aggregation property is deteriorated.
- the force S can be arbitrarily set or changed by changing the addition rate of the additive solution using a liquid delivery device, etc.
- the production efficiency decreases because the number of core particles formed per unit time decreases, and if the number of core particles formed is increased by increasing the addition time, the generated core particles grow in parallel. As a result, the particle size distribution deteriorates. Therefore, in the present invention, it is preferable to set the molar addition rate in the nucleation step to be 0.1 mol / min or more per 1 mol of the alkaline earth metal carbonate formed in the step. Furthermore, 0.2-4 mol / min is preferable, and 0.5-2 mol / min is more preferable.
- the mole addition acceleration is higher than 4 mol / min, the stirring efficiency in the reaction vessel is relatively lowered, and non-uniform core particles are generated, or aggregation due to an increase in local core particle density is suspended. The mind increases.
- the liquid temperature in the reaction vessel can be maintained higher than the nucleation step as necessary (aging step).
- aging step a phenomenon occurs in which particles with a small particle size dissolve and particles with a large particle size grow (ostwald ripening). Therefore, in the present invention, the ripening step can be regarded as a part of the particle growth step.
- the particle growth step is preferably performed at a temperature equal to or higher than that of the nucleation step in order to increase the growth rate of the particles. Specifically, it is preferably performed between 0 to 60 ° C. At a temperature lower than 0 ° C, a sufficient particle growth rate cannot be obtained! / Therefore, it takes a long time for the particle growth process, and at 60 ° C or more, the diameter of the acicular particles increases and the aspect ratio increases. It becomes difficult.
- the present invention is characterized in that the dispersion operation is performed after the nucleation step and / or after the grain growth step.
- the dispersion operation is performed for the purpose of peptizing aggregated particles generated in the nucleation process and / or particle growth process into primary particles, and at least from the end of the nucleation process to the start of the particle growth process. It is preferable to be carried out both after the completion of the nucleation step and after the start of the particle growth step and after the end of the particle growth step. Furthermore, it can be carried out in the middle of the nucleation step and the particle growth step as necessary.
- the dispersing operation can be performed in a reaction vessel, or the reaction solution can be temporarily transferred to another vessel during the dispersing operation.
- the nucleation step is completed as in the present invention.
- descending by carrying out the dispersion operation in a solution state in the presence of an anti-agglomeration agent, it is possible to prevent excessive dispersion such that the primary particles are destroyed and reaggregation of the particles after peptization.
- the time required for the dispersion operation varies depending on the aggregation state of the particles and the power of the disperser to be used, it is preferable to determine by confirming the peptization state.
- a particle size measuring device or a turbidimeter can be used. Particle size measurement When measuring the change in particle size and turbidity during the dispersion process with an instrument or turbidimeter, the particle size and turbidity decrease as the agglomerated particles are peptized, and most of the particles become primary particles. Then it converges to a certain value.
- the measured values are dispersed until they converge.
- media dispersers In the dispersion operation of the present invention, media dispersers, ultrasonic dispersers, and high-speed agitating dispersers can be used! Or, or they can be used in combination.
- a media-type disperser is one in which beads or the like are introduced into an apparatus, and the particles are dispersed by collision or breakage between bead particles.
- an apparatus that can be used in the present invention, Kotobuki Industries Apex Mill, Yashaza Industries LMZ, etc.
- beads having a small particle size In order to break up the agglomeration without crushing the primary particles, it is often preferable to use beads having a small particle size. Specifically, it is preferable to use beads having an average particle size of 0.3 mm or less. More preferably, it is preferable to use beads having an average particle diameter of 0.1 mm or less.
- glass, titania, alumina, zircoua or the like can be used.
- An ultrasonic disperser performs dispersion using the vibration (vacuum bubble) force generated by ultrasonic waves S.
- SMT The company UH150 and Nippon Seiki Seisakusho US-300T.
- the high-speed agitation type disperser disperses particles by the shearing force in the vicinity of the agitation blades that are agitated at high speed.
- the aspect ratio is the length (major axis diameter) and diameter of particles having an acicular shape.
- the present invention is particularly useful for producing an alkaline earth metal carbonate having an acicular shape having an average aspect ratio of 2 or more.
- the average aspect ratio is It is preferably 2 or more, more preferably 5 or more, and further preferably 5 or more and 50 or less.
- acicular particles having a high aspect ratio there are a method of forming nuclei particles having a high aspect ratio in the nucleation step and a method of increasing the aspect ratio in the particle growth step. An attempt to increase the ratio often involves deterioration of the particle size distribution.
- the particle size distribution is more important than the aspect ratio as a characteristic of the core particles obtained in the nucleation step. This is because the formation of more uniform nuclei at the nucleation stage greatly contributes to the improvement of the particle size distribution after particle growth. Therefore, according to the present invention, it is preferable that (I) the particle size distribution is not deteriorated at the nucleation stage. It is preferable to form a high aspect ratio particle by selectively growing the major axis diameter while suppressing the growth.
- Power S is preferable, 3 or more is more preferable, and 5 or more is more preferable.
- a and b are each
- a and b are the average major axis diameter and minor axis diameter of the particles at the end of the grain growth process, respectively. is there.
- a and b are the average major axis diameter and minor axis diameter of the particles at the end of the grain growth process, respectively. is there.
- V (a -a) / (bb)
- the alkali according to the present invention in the method for producing the earth metal carbonate particles, it is preferable that the V force is 3 or more. More preferably, it is 5 or more, more preferably 5 or more and 50 or less, and particularly preferably 5 or more and 10 or less.
- the particle diameter is represented by the diameter of a circle having an area equal to the projected area of the alkaline earth metal carbonate particles, and the average particle diameter is obtained by obtaining individual particle diameters of 300 or more particles. Means the arithmetic average value obtained.
- the particle size distribution is expressed as the value obtained by dividing the standard deviation of each particle size used to determine the average particle size by the average particle size and multiplying by 100.
- Particle size distribution (%) standard deviation of particle size / average particle size particle X 100
- the projected area and average particle diameter of the particles can be obtained from the particle image of the electron micrograph using an image analyzer.
- the present invention is useful for producing alkaline earth metal carbonate particles having an excellent particle size distribution.
- the alkaline earth metal carbonate particles according to the present invention preferably have a particle size distribution of 35% or less, more preferably 30% or less.
- the average particle size is preferably 60 to 220 nm or less, more preferably 70 to 200 nm or less.
- the long axis, short axis, and projected area of each particle required for calculating the above average aspect ratio and average particle diameter can be measured from an electron microscope image, and an image analyzer can be used if necessary. Can also be requested.
- Alkaline earth metal carbonate particles having an acicular shape often cause aggregation of particles joined in the major axis direction during nucleation, which causes deterioration in distribution of the major axis diameter.
- particle aggregation often occurs in the minor axis direction during grain growth, the distribution of minor axis diameter is deteriorated.
- the particle cohesiveness is improved by the production method of the present invention, it is expected that both the major axis diameter and the minor axis diameter are improved.
- the dispersion operation is performed before the start of the particle growth process (dispersion operation A).
- Operation B) mainly improves the distribution of the short axis diameter. That is, by carrying out the combination of the dispersion operation A and the dispersion operation B, the effect of improving the distribution of both the major axis diameter and the minor axis diameter can be obtained.
- the major axis diameter distribution is preferably 40% or less, preferably 30% In More preferably.
- the average value of the major axis diameter is preferably from 150 to 450 nm, more preferably from 200 to 450 nm, and more preferably from 200 to 400 nm.
- the minor axis diameter distribution is preferably 35% or less, more preferably 30% or less.
- the average value of the minor axis diameter (20-20 nm is preferable, 20-70 nm is more preferable, 20-60 nm is more preferable! / ,.
- a force that can arbitrarily change the molar ratio of the raw materials (alkaline earth metal salt and carbonate) consumed in the nucleation step and the particle growth step is an acicular shape having an average aspect ratio of 2 or more.
- the present invention in the configuration it is preferred instrument further that the molar ratio of alkaline earth metal carbonate is formed in the nucleus formation step below 50 mol% is rather preferably 30 mol% or less, 20 mole 0/0 The following is more preferable.
- an aggregation inhibitor it is necessary to add an aggregation inhibitor to at least the liquid in the reaction vessel before the start of the nucleation step in order to prevent particle aggregation.
- an agglomeration inhibitor may be added to the carbonate solution.
- the aggregation inhibitor that can be used in the present invention is a compound that has an adsorptivity to alkaline earth metal carbonate particles, acts as a steric hindrance, and can prevent aggregation between the particles. Things and synthesis.
- Examples of the aggregation inhibitor that can be preferably used in the present invention include nitrogen-containing polymers such as polyamide, polyethylenimine, and polybulurpyrrolidone, neutral polymers such as polybulbutyral and polybulal alcohol, carboxymethylcellulose, and methylcellulose. It is possible to use water-soluble polymers such as cellulose polymers such as hydroxyethyl cellulose. Among them, a polymer having an amide group is a preferable compound. There is no restriction on the average molecular weight of the polymer, but if the molecular weight is small, the aggregation inhibiting effect is too small.
- the average molecular weight of the aggregation inhibitor used in the present invention is preferably 10,000 to 1,000,000, more preferably 30,000 to 500,000, and still more preferably 50,000 to 300,000.
- the addition amount of the anti-aggregation agent is about 0. ! ⁇ 15% by weight is preferred 0.;! ⁇ 10% by weight is more preferred 0.5 ⁇ ; 10% by weight is more preferred.
- the anti-aggregation agent used may have a negative effect on product performance, such as when the final product is a hydrophobic paint or plastic. It can also be removed by a solvent replacement step or the like.
- At least a part of the nucleation step and the particle growth step can be performed under the condition that the liquid in the reaction vessel is in excess of alkaline earth metal ions.
- the method of operating the liquid in the reaction vessel so that the alkaline earth metal ions are excessive but a necessary amount of alkaline earth metal is added separately from the alkaline earth metal salt solution added by the double jet method.
- a method of adding a metal salt or a solution thereof into the reaction vessel or a method of adjusting the balance between the flow rate of the alkaline earth metal salt solution and the carbonate solution added by the double jet method is preferable.
- the excess amount of alkaline earth metal ions is preferably 0.001 to 0.5 monolayer /: L in terms of monolith concentration of alkaline earth metal dissolved in the liquid in the reaction vessel. 0.0 to 0.5 mol / L is more preferable. 0.01-0.2 mol / L is more preferable. Beyond this range, the risk of agglomeration increases.
- a nucleation step it is preferable to carry out at least a part of the particle growth step under conditions of pH 9 or higher. Furthermore, a pH value of 9 to 13.5 is preferred. A pH value of 10 to 13 is particularly preferred. Even if the pH value is higher than this, the effect on anisotropic growth will not change if aggregation is suppressed.
- At least a part of the nucleation step or the particle growth step can be carried out in the presence of a form control agent.
- a form control agent examples include amines. Among them, primary amines and amino alcohols can be preferably used in the present invention.
- Examples of the form control agent applicable to the present invention include diamine compounds and amino alcohol compounds. Specifically, ethylene diamine, diethylene triamine, triethylene tetramine, propylene diamine, N, N —Dimethylethanolamine, N, N—Jetyl Examples include ethanolamine, 2- (2-aminoethylamino) ethanol, N-methylethanolamine, N-methylethanolamine, 2-aminoethanol and the like.
- the liquid in the reaction vessel may contain alcohol.
- the alcohol may be added to the liquid in the reaction vessel at any point in the nucleation step or particle growth step. At least before the start of the particle growth step, it is preferable to add alcohol before the start of the nucleation step. More preferably, the liquid contains alcohol.
- the alcohol used in the present invention can be mixed with water at an arbitrary ratio. Specifically, at least one of methanol, ethanol, n-propyl alcohol, and i-propyl alcohol should be used. Is preferred.
- the total amount of these solvents is used in a range not exceeding 10% by volume of the liquid in the reaction vessel.
- an ultrafiltration membrane having appropriate filtration characteristics is selected in consideration of the particle size of the formed particles and the molecular weight of the anti-aggregation agent, and concentration / dilution operations are performed using the ultrafiltration membrane after the particle growth process is completed. By doing so, it is possible to remove the aggregation inhibitor.
- a desalting and washing treatment can be performed, or a substitution treatment with an appropriate solvent can be performed for various purposes.
- the solvent is less soluble than the solvent in the particle growth step, and more preferably by replacing the solvent with an alkaline earth metal carbonate such as alcohol.
- the produced alkaline earth metal carbonate particles are used as fillers or pigments for rubber, plastic, paint, etc.
- a dispersion in an appropriate solvent can be obtained without passing through a drying step. Not only can the step of pulverizing the solid after drying be omitted, but also agglomeration generated by drying the particles can be avoided, and the effect obtained when the primary particles are blended can be effectively expressed.
- the ultrafiltration membrane that can be used in the present invention is not particularly limited as long as it has a fractional molecular weight capable of filtering out alkaline earth metal carbonate particles and has resistance to a solvent. There is no.
- Solution A1 was placed in a 2 L stainless steel reaction vessel and maintained at 5 ° C, and the pH was adjusted to 11.5 with 5% aqueous sodium hydroxide solution while stirring at lOOOrpm. Subsequently, 40 ml each of the solution B1 and the solution C1 cooled to 4 ° C were equalized using the double jet method! /, Added at a rate of addition, and a constant flow rate into the solution A1 for 30 seconds. .
- solution A2 cooled to 5 ° C. was added while stirring the reaction solution, and the pH was adjusted to 11.5 with 5% aqueous sodium hydroxide solution. Subsequently, the remaining amount of 160 ml of solution B1 and solution C1 held at 5 ° C was added at the same rate to match the increase in surface area accompanying particle growth. Using the double jet method while accelerating the flow rate, it was added to the liquid in the reaction vessel over 160 minutes.
- the membrane was washed with water using an ultrafiltration membrane, and further replaced with an ethanol solvent using the ultrafiltration membrane to produce particles 1.
- reaction solution was collected during and after the particle growth step, and the force s confirmed using an electron microscope was not observed, and the generation of new core particles in the particle growth step was not observed. Also
- Particle 3 was produced in the same manner as Particle 1 except that the dispersion operation was performed using UH150).
- Particle 4 was produced in the same manner as Particle 3 except that Solution A3 prepared as follows was used instead of Solution A1.
- Solution A3 Strontium Chloride Hexahydrate
- Particle 5 was produced in the same manner as Particle 3 except that Solution A4 prepared as follows was used instead of Solution A1.
- Solution A4 Strontium Chloride Hexahydrate 5.3g and polybulurpyrrolidone as anti-agglomeration agent
- Particle 6 was produced in the same manner as Particle 1 except that Solution A1 and Solution A2 were prepared and used except for the anti-aggregation agent polybulpyridone.
- Particle 7 was produced in the same manner as in the production of Particle 1 except that the dispersion operation after completion of the nucleation step was not performed.
- Particles 8 were produced as follows without separating the nucleation step and the particle growth step.
- Solution A3 was placed in a 2 L stainless steel reaction vessel and maintained at 5 ° C, and the pH was adjusted to 12 with 5% aqueous sodium hydroxide solution while stirring at lOOOrpm. Subsequently, Solution B1 kept at 5 ° C. and Solution C1 were equalized! /, And added to the liquid in the reaction vessel for 200 minutes at the addition rate and at a constant flow rate using the double jet method. Next, after performing dispersion operation using an ultrasonic disperser (SMT UH150), washing with water using an ultrafiltration membrane, and further substituting with an ethanol solvent using an ultrafiltration membrane, the particles are used. Manufactured.
- SMT UH150 ultrasonic disperser
- each particle produced as described above at least 300 particles were photographed with a scanning electron microscope and the shape thereof was observed.
- the shape of the particles occupying the main body was acicular particles, spherical particles, and irregularly shaped irregular shapes. Classified into particles.
- Table 1 shows the results obtained as described above. Note that the particle 6 has a force that cannot measure the short axis diameter and the long axis diameter at which particle aggregation is intense. [0116] [Table 1]
- the constituent requirement of the present invention that is, "alkaline earths using the double jet method in a solution containing an anti-aggregation agent" It is a production method in which a metal salt solution and a carbonate solution are reacted, wherein the production method includes a particle growth step after the nucleation step, and the dispersion operation is performed after the nucleation step is completed. It can be seen that this is a necessary condition for improving the child distribution.
- the dispersion operation method after completion of the nucleation step and after the completion of the particle growth step is changed from an ultrasonic disperser to a media disperser (Kotobuki Industries Avex Minore) or a high-speed stirring dispersion.
- Particles 1-9 and Particles 10 were produced in the same manner as Particles 3 except that the machine was changed to a machine (Primics Co., Ltd. ⁇ Homomixer MARKII).
- Dispersion operation using a media disperser or a high-speed stirring disperser was also performed until the turbidity of the reaction solution converged to a constant value. Analysis of Particle-9 and Particle-10 confirmed that the particles were excellent in distribution as in Particle-3.
- Particles As a result of measurement of each property by the same method as in Example 1, the minor axis diameter was attributed to particle aggregation that occurred in the drying process. In addition, deterioration of the long axis diameter distribution was observed. That is, in the method for producing alkaline earth metal carbonate particles of the present invention, an ultrafiltration membrane may be used when a water washing treatment is performed for the purpose of removing excess anti-aggregation inhibitor, shape control agent, salt, and the like. It was confirmed that this was preferable in preventing the aggregation of particles.
- Barium chloride and calcium carbonate were prepared by changing the strontium chloride hexahydrate used in the production of the particles 1 to 8 of Example 1 to barium chloride and calcium chloride, respectively.
- the alkaline earth metal carbonate particles produced by the production method of the present invention were Similar to the strontium carbonate particles according to the present invention described in Example 1, it was confirmed to have a needle-like shape and an excellent particle size distribution.
- a 4000 ml aqueous solution (solution A1) containing 200 ml of ethanol and 120 g of polyvinyl pyrrolidone (molecular weight: 130,000) as an anti-aggregation agent was prepared in a 8 L stainless steel reaction vessel.
- 1000 ml of 1.0 mol / L aqueous solution prepared from strontium chloride hexahydrate (solution B 1) and 1000 ml of 1.0 mol / L aqueous solution prepared from sodium carbonate (solution C1) were prepared.
- a dispersion operation was performed using an ultrasonic disperser (SMT U HI 50). The dispersion operation was performed until the turbidity of the reaction solution decreased and converged to a certain value.
- SMT U HI 50 an ultrasonic disperser
- the membrane was washed with water using an ultrafiltration membrane, and further replaced with an ethanol solvent using the ultrafiltration membrane to produce particles-21.
- the X-ray diffraction spectrum of the obtained reaction product was measured, and it was identified that the reaction product was strontium carbonate.
- solution A 2 an aqueous solution containing 200 ml of ethanol, 0.1 mol of strontium chloride hexahydrate and 120 g of polybulurpyrrolidone (molecular weight: 130,000) as an aggregation inhibitor was prepared.
- solution B2 1.0 mol / L aqueous solution prepared from strontium chloride hexahydrate
- solution C2 1.0 mol / L aqueous solution prepared from sodium carbonate were prepared.
- the nucleation step, dispersion operation 1, and ripening step were performed in the same manner except that Solution A2, Solution B2, and Solution C2 were used instead of Solution Al, Solution Bl, and Solution C1. .
- a dispersion operation was performed using an ultrasonic disperser (SMT U HI 50). The dispersion operation was performed until the turbidity of the reaction solution decreased and converged to a certain value.
- SMT U HI 50 an ultrasonic disperser
- Particles 23 were prepared in the same manner as in the preparation of Particles 22 except that instead of Solution A2, Solution A3 shown below was used.
- Solution A3 had a pH value of about 12.
- Particle-24 was prepared in the same manner as in the preparation of the particle-23 except that the nucleation step and the particle growth step were changed to the conditions shown below.
- Particle-25 was prepared in the same manner as in the preparation of the particle-23 except that the nucleation step and the particle growth step were changed to the conditions shown below.
- Solution B2 was also added at the same flow rate as solution C2, and the addition was completed prior to solution C2.
- particles 26 were prepared in the same manner except that the addition time of the solution B 1 and the solution C 1 in the nucleation step was 20 minutes.
- the molar addition rate per mol of alkaline earth metal carbonate formed in the nucleation process corresponds to 0.05 mol / min.
- Particle-27 was prepared in the same manner except that the preparation of the particle-21 was changed to the following nucleation step.
- particles 28 were prepared in the same manner except that the addition time of the solution B 1 and the solution C 1 in the particle growth step was shortened to 40 minutes.
- the length (major axis diameter) and diameter (minor axis diameter) of the particles were measured using a scanning electron microscope, and the ratio (major axis diameter / The minor axis diameter) was calculated as the aspect ratio, and the average value was obtained, which was used as the average aspect ratio.
- Each of the alkaline earth metal carbonate particles prepared above was photographed using a scanning electron microscope, the diameter of a circle having an area equal to the projected area of the particles was defined as the particle size, and each of the individual particles measured for 300 particles was measured. The arithmetic average value of the particle diameter was determined and used as the average particle diameter.
- a value obtained by dividing the standard deviation of the individual particle sizes obtained by the measurement of the average particle size by the average particle size was multiplied by 100 to obtain a particle size distribution.
- the particles 21 prepared according to the conditions specified in the present invention are alkaline earth metal carbonates having a high aspect ratio and excellent particle size distribution.
- Particle-26 which is a comparative example, is formed in the nucleation process because it takes time (20 minutes) to add the molar addition rate as low as 0 ⁇ 05 mol / min in the nucleation process. Nuclei grown in parallel, and the average ratio is small because V is small In addition, the particle size distribution is deteriorated.
- the particle 27 has a non-uniform particle shape in which acicular particles and spherical particles are mixed, and in addition, the particle size distribution is deteriorated. ing.
- the particle 28 since the addition rate in the particle growth process is not appropriately controlled, the particle 28 also generates nuclei in the particle growth process, resulting in an uneven particle shape in which columnar particles and spherical particles are mixed. This causes deterioration of the particle size distribution.
- the particle 29 is a force S, which is a particle preparation by changing the double jet method of the particle 21 to the single jet method, and the grown particle is a needle-like particle unlike the particle 21. It was a mixture of negative particles. It is probable that the icidal particles were agglomerated during the nucleation process, and the aggregates were acicularly grown during the particle growth process. It is presumed that the nucleation of particles 29 in the nucleation step was caused by the fact that nucleation was performed under a high salt concentration condition because strontium chloride was added in advance to the reaction solution.
- the particle preparation is carried out under an excess of alkaline earth metal ions, so that the particle cohesiveness is improved and the particle size is reduced and the particle size distribution is improved. I can understand that they are connected.
- the aspect ratio can be remarkably increased by applying the form control agent to the production method of the present invention. In this case, the deterioration of the particle size distribution accompanying the increase in the aspect ratio is hardly observed.
- the comparison of particles 21, 24 and 25 shows that the aspect ratio can be adjusted by the distribution of the molar ratio between the nucleation step and the particle growth step in the production method of the present invention. .
- the molar ratio in the nucleation step exceeds 50%, the aspect ratio after grain growth decreases, and the characteristics expected for acicular or columnar particles can be sufficiently obtained. It becomes difficult and difficult.
- barium chloride and calcium carbonate were prepared by changing the strontium chloride hexahydrate used to barium chloride or calcium chloride, respectively.
- the obtained particles were confirmed to have a needle-like or columnar shape as in the case of the above-mentioned strontium carbonate particles—30 and excellent in particle size distribution.
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Geology (AREA)
- Inorganic Chemistry (AREA)
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Abstract
L'invention concerne un procédé de fabrication de particules d'un carbonate de métal alcalino-terreux, lesdites particules ayant une forme aciculaire et une distribution améliorée de diamètre de particule. Dans le procédé, la forme et la sensibilité à l'agrégation des particules d'un carbonate de métal alcalino-terreux peuvent être contrôlées. L'invention concerne également des particules d'un carbonate de métal alcalino-terreux obtenues par le procédé. Dans le procédé de fabrication des particules d'un carbonate de métal alcalino-terreux, une solution d'un sel de métal alcalino-terreux est amenée à réagir avec une solution de carbonate dans une solution contenant un inhibiteur d'agrégation par le procédé à double jet pour former des particules aciculaires ayant un rapport d'allongement moyen de 2 ou plus. Le procédé est caractérisé par le fait qu'il comprend une étape de formation des noyaux, une étape de croissance de particules conduite après l'étape de formation des noyaux, et une opération de dispersion conduite après l'achèvement de l'étape de formation des noyaux.
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2006252438A JP2008074634A (ja) | 2006-09-19 | 2006-09-19 | アルカリ土類金属炭酸塩粒子の製造方法及びアルカリ土類金属炭酸塩粒子 |
JP2006-252438 | 2006-09-19 | ||
JP2007-004404 | 2007-01-12 | ||
JP2007004404A JP2008169086A (ja) | 2007-01-12 | 2007-01-12 | アルカリ土類金属炭酸塩粒子の製造方法 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO2008035538A1 true WO2008035538A1 (fr) | 2008-03-27 |
Family
ID=39200367
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP2007/066447 WO2008035538A1 (fr) | 2006-09-19 | 2007-08-24 | Procédé de fabrication de particules de carbonate de métal alcalino-terreux et particules de carbonate de métal alcalino-terreux |
Country Status (1)
Country | Link |
---|---|
WO (1) | WO2008035538A1 (fr) |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5551852B2 (fr) * | 1977-09-30 | 1980-12-26 | ||
JPS59203728A (ja) * | 1983-05-06 | 1984-11-17 | Earth Chem Corp Ltd | 炭酸カルシウム結晶の製造方法 |
JPH05155615A (ja) * | 1991-12-06 | 1993-06-22 | Shin Etsu Chem Co Ltd | 針状晶炭酸バリウムの製造方法 |
JP2001139328A (ja) * | 1999-11-10 | 2001-05-22 | Nittetsu Mining Co Ltd | 分散性に優れた紡錘状炭酸カルシウムの製造方法 |
JP2006021988A (ja) * | 2004-06-08 | 2006-01-26 | Fuji Photo Film Co Ltd | 炭酸塩の製造方法 |
JP2006124199A (ja) * | 2004-10-26 | 2006-05-18 | Ube Material Industries Ltd | 針状炭酸ストロンチウム粒子 |
JP2006169038A (ja) * | 2004-12-15 | 2006-06-29 | Fuji Photo Film Co Ltd | 炭酸塩の製造方法 |
JP2006176367A (ja) * | 2004-12-22 | 2006-07-06 | Fuji Photo Film Co Ltd | 炭酸塩結晶の製造方法 |
-
2007
- 2007-08-24 WO PCT/JP2007/066447 patent/WO2008035538A1/fr active Application Filing
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5551852B2 (fr) * | 1977-09-30 | 1980-12-26 | ||
JPS59203728A (ja) * | 1983-05-06 | 1984-11-17 | Earth Chem Corp Ltd | 炭酸カルシウム結晶の製造方法 |
JPH05155615A (ja) * | 1991-12-06 | 1993-06-22 | Shin Etsu Chem Co Ltd | 針状晶炭酸バリウムの製造方法 |
JP2001139328A (ja) * | 1999-11-10 | 2001-05-22 | Nittetsu Mining Co Ltd | 分散性に優れた紡錘状炭酸カルシウムの製造方法 |
JP2006021988A (ja) * | 2004-06-08 | 2006-01-26 | Fuji Photo Film Co Ltd | 炭酸塩の製造方法 |
JP2006124199A (ja) * | 2004-10-26 | 2006-05-18 | Ube Material Industries Ltd | 針状炭酸ストロンチウム粒子 |
JP2006169038A (ja) * | 2004-12-15 | 2006-06-29 | Fuji Photo Film Co Ltd | 炭酸塩の製造方法 |
JP2006176367A (ja) * | 2004-12-22 | 2006-07-06 | Fuji Photo Film Co Ltd | 炭酸塩結晶の製造方法 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US11958116B2 (en) | Stable dispersions of monocrystalline nanometric silver particles | |
JP5350232B2 (ja) | 水酸化アルミニウムの製造方法 | |
Wu et al. | Magnesium hydroxide nanoparticles synthesized in water-in-oil microemulsions | |
WO2007088707A1 (fr) | Agent de formation de micropore pour film de resine poreux et composition pour film de resine poreux contenant l'agent | |
JP3058255B2 (ja) | 沈降製炭酸カルシウムの製造方法 | |
JP5387809B2 (ja) | バテライト型球状炭酸カルシウム及びその製造方法 | |
CN108137345B (zh) | 羟基氧化铁纳米分散液 | |
KR101474041B1 (ko) | 고분산성 알칼리 토금속 탄산염 미분말 및 그 제조 방법 | |
Schlomach et al. | Investigation of precipitation of calcium carbonate at high supersaturations | |
JPS62202817A (ja) | 微細炭酸カルシウム粒子の製造方法 | |
JP5019556B2 (ja) | 多孔質粒子およびその製造方法 | |
KR101378470B1 (ko) | 금속 복합 산화물의 합성 방법 및 상기 합성 방법에 의해 얻어지는 금속 복합 산화물 | |
JP7085325B2 (ja) | アラゴナイト型軽質炭酸カルシウム及びその製造方法 | |
JP5474310B2 (ja) | 粒状炭酸バリウム組成物粉末 | |
WO2008035538A1 (fr) | Procédé de fabrication de particules de carbonate de métal alcalino-terreux et particules de carbonate de métal alcalino-terreux | |
JPH054929B2 (fr) | ||
JP5096028B2 (ja) | 軽質炭酸カルシウム−シリカ複合物及びアルミニウム系水溶性無機化合物を含むスラリー | |
JP2008169086A (ja) | アルカリ土類金属炭酸塩粒子の製造方法 | |
Mikami et al. | Polyelectrolyte‐Assisted Reactive Crystallization of SrSO4 to Obtain Monodispersed Nano/Micro‐Particles | |
JP2008110885A (ja) | アルカリ土類金属炭酸塩粒子の製造方法 | |
JPH07267634A (ja) | 板状炭酸カルシウムの製造方法 | |
JP2008074634A (ja) | アルカリ土類金属炭酸塩粒子の製造方法及びアルカリ土類金属炭酸塩粒子 | |
JP2008144010A (ja) | 樹脂組成物の製造方法及び樹脂組成物フィルム | |
TWI427038B (zh) | 氫氧化鋁之製造方法 | |
JP2008169087A (ja) | アルカリ土類金属炭酸塩粒子分散液、及びその製造方法 |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 07792976 Country of ref document: EP Kind code of ref document: A1 |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
122 | Ep: pct application non-entry in european phase |
Ref document number: 07792976 Country of ref document: EP Kind code of ref document: A1 |