High- speed collision reaction method

Abstract: Two or more substances are flowed from different inflow passages, and collided against each other at a flow rate of 4m/sec or higher to cause a uniform reaction with each other for a short time. This method is advantageous in production of dispersion liquid containing very fine particles of submicron.

Description: This invention relates to a high speed collision reaction method for causing chemical reaction between two kinds of substancesby high speed collision. To mix and react two or more reactive substances, there has been known a method which uses a batch-type reactor including an agitation chamber. In this method, two or more substances are supplied into the agitation chamber simultaneously or successively, and are reacted with each other with agitation in the agitation chamber. Also, there has been known a method which uses a reactor including an agitation flow passage, such as static mixer. The agitation flow passage is provided with blades therein to cause turbulence. In this method, two or more substances are flowed in the agitation flow passage, and are reacted with each other with agitation in the agitation flow passage. In the method using a batch-type reactor, two or more substances are supplied from different sources into the agitation chamber having a fixed volume simultaneously or successively, and are agitated for a specified time to cause a reaction between the substances. When the reaction is completed or reached to an equilibrium state, a product is taken out. However, this method has the following problems. If a state change occurs in a reaction system, e.g., an increase in the viscosity of reactive substance, the substances are not agitated uniformly, and the reaction efficiency consequently decreases. Also, if an unmixable part comes into existence and stays in a reaction system for a long time, the unmixable part aggregates into a considerable mass, thus making it difficult to produce a finely dispersed mixture. Further, keeping the reaction system in the fixed chamber for a long time inevitably causes changes in the physical and chemical conditions, for example, variations in the amount, concentration, and pH of reactive substances. It is very difficult to keep the reaction system at constant conditions. In the batch-type reaction method, in principle, the reaction is conducted per batch. To improve this drawback, there has been proposed a reactor system in which a plurality of agitation chambers are connected in series to perform a continuous reaction. In this case, however, the concentration of reactive substances changes from an initial chamber to a final chamber. Usually, the concentration decreases toward the final chamber. Accordingly, the reaction efficiency lowers toward the final chamber. Thus, it has been very difficult to attain a required reaction efficiency. On the other hand, the method using the agitation flow passage also has the following problems. In this method, blades or other special elements are provided in the agitation flow passage to forcibly generate turbulence. A primary substance is flowed in a direction or circulated in the agitation flow passage in a turbulence state. A flow of secondary substance is joined to the flow of primary substance to cause reaction between the substances. However, contact of the primary substance and the secondary substance inevitably occurs before the secondary substance enters in the turbulence region, consequently causing a heterogeneous reaction though for a short time. Further, even if flows of two or more substances are met at the same time to cause homogeneous reaction, a high reaction efficiency cannot be attained. There has been known another method which uses an ejector. In this method, a large flow of primary substance is produced. A secondary substance is ejected into the large flow of primary substance at a high speed to react with the primary substance. However, this method is not suitable for the case that material substances have a high viscosity or the case that reaction product has a high viscosity. Further, the control of substance mixing proportion is very difficult. Accordingly, this method cannot be applied other than a limited field. WO 94/07582 discloses a dual jet crystallizer apparatus comprising a crystallization or mixing chamber (10) having opposed angularly disposed arms (11) which removably receive jet nozzles (13). One end of the chamber is provided with means to discharge crystallized product therefrom while the other end is equipped with means to adjust the crystallization volume within the chamber (10). The angular arms (11) are disposed within specified angular tolerances with respect to the longitudinal axis of the chamber. One of the jet nozzles (13) is provided with means at one end to receive and deliver to the chamber compound to be crystallized while one end of the other jet nozzle (13) is provided with means to receive and deliver to the chamber (10) a crystallization agent for the compound. The opposite ends of each of the jet nozzles (13) have means to removably secure them to the angular arms (11) and the ends thus secured have a nozzle tip section formed therein defining an orifice having an elongated bore. Means are provided intermediate the ends of each jet nozzle (13) for further adjusting the distance of the jet nozzle tips with respect to the longitudinal axis of the chamber (10). JP 63 278534 (the English abstract) discloses a method and a device for a complex collision type mixing. It is further disclosed a method of obtaining a mixture by colliding liquid to the surface of the plate 7 which is placed in the mixing chamber 1 and secondly by linear concentric collision in a second mixing chamber 6. JP 02 261525 (the English abstract) discloses an emulsifying device comprising flow passages 5, 6, 9 and 10 which are closed by two sheets of liner members 15 and 16 consisting of a hard plate material. In the member 15 disposed to the influent side, two through-holes 15b and 15c through which each mixing liquid ejected from nozzles 2 and 3 is allowed to pass are formed in the positions symmetrical to the center of plate surface, and a groove part 15a is formed in one side of the plate surface so as to communicate the end parts of the through-holes. In the member 16 disposed to the effluent side of the member 15 with tight contact therewith, a groove part 16a is formed in the confronting surface in tight contact with the member 15 so as to orthogonally cross the groove part 15a, and two through-holes 16b and 16c for discharge are formed at both outer ends of the groove part 16a, so that the emulsification is carried out while mixing liquid is passed through the members 15 and 16. It is an object of the present invention to provide a high speed collision reaction method which has overcome the problems residing in the prior art. According to an aspect of the present invention, a method for causing a reaction between two or more reactive substances, comprises joining together first and second collinear walled inlet passages and a walled outlet passage to form a collision enclosure defined by the joined walls of said passages; introducing at least one reactant along said first inlet passage and at least one other reactant along said second inlet passage into said collision enclosure; effecting a collision between said two introduced reactants within said collision enclosure at a flow rate of 4 m/sec or higher and thereby causing a chemical reaction and producing fine particles as a reaction product; and removing the reaction product from the collision enclosure via said outlet passage. In this method, the flows of reactive substances are collided against each other at a flow rate of 4 m/sec or higher to cause a reaction. Accordingly, very fine particles can be produced more efficiently. Also, since the reaction is attained for a very short time, the conditions for the reaction can be controlled more easily. The above and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and drawings. Figure 1 is a top plan view showing a high speed collision reactor embodying the present invention; Figure 2 is a sectional view taken along the line II-II in Figure 1; Figure 3 is a sectional view taken along the line III-III in Figure 1; Figure 4 is a sectional view taken along the line IV-IV in Figure 2; Figure 5 is a conceptual diagram illustrating a first high speed collision reaction manner embodying the present invention; Figure 6 is a graph illustrating a relationship between the colliding flow rate and the average diameter of produced particles; Figure 7 is a conceptual diagram illustrating a flow control conducted for produced particles; Figure 8 is a conceptual diagram illustrating another flow control conducted for produced particles; Figure 9 is a conceptual diagram illustrating still another flow control conducted for produced particles; Figure 10 is a conceptual diagram illustrating a second high speed collision reaction manner embodying the present invention; Figure 11 is a conceptual diagram illustrating a third high speed collision reaction manner embodying the present invention; Figure 12 is a conceptual diagram illustrating a fourth high speed collision reaction manner embodying the present invention; Figure 13 is a conceptual diagram illustrating a fifth high speed collision reaction manner embodying the present invention; Figure 14 is a conceptual diagram illustrating a sixth high speed collision reaction manner embodying the present invention; Figure 15 is a conceptual diagram showing a first combination of a high speed collision reaction and an emulsion dispersion; Figure 16 is a conceptual diagram illustrating a seventh high speed collision reaction manner embodying the present invention; Figure 17 is a conceptual diagram illustrating a second combination of a high speed collision reaction and an emulsion dispersion; Figure 18 is a conceptual diagram illustrating a eighth high speed collision reaction manner embodying the present invention; Figure 19 is a conceptual diagram illustrating a third combination of a high speed collision reaction and an emulsion dispersion; and Figure 20 is a conceptual diagram illustrating a fourth combination of a high speed collision reaction and an emulsion dispersion. According to the present invention, flows of two or more substances in the form of liquid and/or gas having a reactivity with each other are joined in such a way that substances collide with each other at a high speed to react with each other. Figures 1 to 4 show a reactor embodying the present invention. This reactor is configured so as to make collision reaction between two substances. Figure 1 is a top plan view of the reactor, Figure 2 being a sectional view along the line II-II in Figure 1, Figure 3 being a sectional view along the line III-III in Figure 1, and Figure 4 being a sectional view along the line IV-IV in Figure 2. This reactor includes two rectangular blocks 1a and 1b which are assembled into one body by being fastened with four bolts 2 at their respective four corners. The upper block 1a is provided with two inlet members 3a and 3b, and an outlet member 4. The inlet members 3a and 3b are respectively formed with inflow passages 5a and 5b communicated with channels 6a and 6b. The channels 6a and 6b, as shown in Figure 4, extend in opposite directions. From a joining portion 7 of the channels 6a and 6b extends a channel 8 in a perpendicular direction to the channels 6a and 6b. The channel 8 is communicated with an outflow passage 9 formed in the outlet member 4. Accordingly, flows of the two substances passed through the channels 6a and 6b collidingly meet each other at the joining portion 7 where reaction occurs. A production C of reaction flows through the channel 8, and the outflow passage 9 to a reservoir arranged outside of the reactor. Specifically, material fluid A and material fluid B are respectively supplied into the inflow passages 5a and 5b at a high speed or high pressure, and are flowed to the joining portion 7 through the channels 6a and 6b. The fluids A and B are met at a flow rate of jet. In the small space of the joining portion 7, the jet flows of the fluids A and B collide with each other at the high speed. Also, furious turbulence and cavitation occur in the small space of the joining portion 7. Further, the fluids A and B collide against an inner wall of the joining portion 7. Accordingly, the fluids A and B are mixed at a high kinetic energy, thus causing reaction between the fluids A and B in a very short time. Figure 5 conceptually shows this high speed collision reaction. In this high speed collision reaction, the reaction rate and reaction state between the two fluids A and B can be easily controlled in accordance with characteristics of the fluids by adjusting the respective flow rates or kinetic energy of the fluids A and B. Also, the respective supply amounts or proportion of the fluids A and B can be easily controlled by providing supply devices (pumps) for the fluids A and B, respectively. In this high speed collision reaction, the flow rate of material fluid is important. The fluids flow at a rate of 4 m/sec or higher, and preferably 7 m/sec or higher, and more preferably 15 m/sec or higher. Such high speed collision reaction makes it possible to produce fine particles in the size of submicron which cannot be produced in the conventional methods. Further, it may be appreciated to perform a processing to suppress or prevent fine particles from aggregating after the reaction, for example, by agitating produced fine particles in a large amount of liquid for a short time. Figure 6 is a graph illustrating a relationship between a flow rate and an average particle diameter. The relationship was obtained in the case where barium chloride and sodium sulfate, used as substances, were collided at a high speed and reacted with each other in the reactor shown in Figures 1 to 4, thereby producing barium sulfate. The reaction was conducted at a number of flow rates, and an average particle diameter of resultant barium sulfate at each flow rate was obtained. When the flow rate in the collision reaction is set at 4 m/sec or higher, an average particle diameter was about 1.0 µm or smaller. When the flow rate was set at 7 m/sec or higher, an average particle diameter was about 0.5 µm or smaller. When the flow rate was set at 15 m/sec or higher, an average particle diameter was about 0.2 µm or smaller. From these results, it can be found that the high speed collision reaction of the present invention can produce remarkably fine particles. On the other hand, the conventional method of reacting two or more substances using jet flows of 1 to 3 m/sec can produce particles not smaller than 3 µm. As described above, the high speed collision reaction of the present invention can produce very fine particles of submicron or dispersions including very fine particles. Further, it is appreciated to add a proper amount of dispersing agent in a reaction system to prevent secondary agglutination after reaction. In this way, a stable dispersion keeping dispersed very fine particles, which has an appearance similar to emulsion or solution, can be obtained. The flow rate- particle diameter relationship shown in Figure 6 refers to the production of barium sulfate fine particles from barium chloride and sodium sulfate. Although the diameter of produced particle slightly varies depending on kinds of material substances, the relationship between the flow rate of material fluids and the diameter of produced particles can be applicable for various kinds of substances. In other words, the diameter of particle noticeably changes above and below the flow rate of 4 m/sec. It has been confirmed that very fine particles, which have not been able to be produced by the conventional methods, can be obtained by colliding material fluids at a flow rate of 4 m/sec or higher. Accordingly, a feature of the method of the present invention is that the flow rate for the collision reaction of two or more substances is 4 m/sec or higher, preferably 7 m/sec or higher, and more preferably 15 m/sec or higher. The reactor shown in Figures 1 to 4 is only an exemplary reactor, and the method of the present invention is not limited to the use of the reactor shown in Figures 1 to 4. Any reactor can be used as far as it has such a construction that two or more substances collide with each other at the above-mentioned high speeds to react them with each other in a very short time, and discharge produced particles. As far as such conditions are satisfied, various modifications can be made on the number and the size of inflow passages, the joining direction of material substances, the shape and structure of the joining portion, and the direction of the outflow passage. However, the reactor shown in Figures 1 to 4 is preferable for the method of the present invention because the construction is very simple and the design and production are thus easy. Specifically, the reactor includes the upper and lower blocks 1a and 1b. The upper block 1a is formed with the inflow passages 5a, 5b, and the outflow passage 9. The lower block 1b is formed with the inflow channels 6a and 6b, the joining portion 7, and the outflow channel 8. Accordingly, the number of inflow passages and channels can be easily changed in accordance with the number of material substances. The inflow channels 6a and 6b, the joining portion 7, and the outflow channel 8 may be formed in the upper block 1a instead of the lower block 1b, or may be formed in both the upper blockla and the lower block 1b. Although the feature of the method of the present invention is that the flows of two or more substances are squarely collided against each other along substantially a line at high speed, the construction of outflow of reaction product is not limited to the specific model but may be modified into various arrangements. For example, as shown in Figures 7 to 9, a reaction product C may be passed through another arrangement in accordance with characteristics of the reaction product C. To reduce the size of the reaction product C more or make more fine particles, a throttling portion S may be formed at an immediate downstream location of the joining portion 7 as shown in Figure 7, or at a downstream location slightly away from the joining portion 7 as shown in Figure 8. Also, it may be appreciated, as shown in Figure 9, to broaden the outflow channel downstream of the joining portion 7 to reduce the pressure of the downstream side, and thereby enhance the collision reaction and make smooth flow of reaction product C. Furthermore, according to the present invention, there may be various modification of high speed collision reaction as follows. As shown in Figure 10, it may be appreciated to collide two material substances A and B in two opposite directions at the same time at a high speed. As shown in Figure 11, four material substances A to D may be collided against one another in two opposite directions at the same time at a high speed. As shown in Figures 12 and 13, two material substances A and B may be collided against each other by ejecting them from oppositely arranged slit nozzles at a high speed. As shown in Figures 14, while a material substance A is flowed in a specified direction at a high rate, four material substances B, C, D, and E are directed to the flow of the substance A at a high flow rate. In this case, the flows of the substances B and C, and the flows of the substances D and E face each other. As shown in Figure 16, material substances A and B may be respectively branched into two flow paths and are collided at two points. After that, reaction product is collided again in a downstream and then discharged in a single path. As shown in Figure 18, material substances A and C, and material substances B and D are respectively collided against each other at different positions. Thereafter, reaction product AC and reaction product BD are respectively branched into two flow paths, and collided against each other at two different points. Reaction product ABCD is collided against each other more downstream, and then discharged in a single flow path. In the reaction manner shown in Figure 14, the substance A may be a reaction medium, and the substances D and E may be primary substances. Prior to collision reaction between the substances D and E using the substance A as reaction medium, the substances B and C, such as surface active agent (dispersing agent etc.), reaction accelerator, reaction auxiliary agent, catalyst may be added and dispersed in the flow of the substance A. Alternatively, the substance A may be a reaction medium, and the substances B and C may be primary material substances. The substances D and E may be a reaction shortstop agent, a secondary reactive substance, a finishing agent, or a modifier and the like, and may be added downstream of the reaction of the substances B and C. Such addition can be applied for the reaction manner shown in Figure 16. More specifically, prior to the collision reaction between the substances A and B, substances C and C' such as surface active agent (dispersing agent etc.), reaction accelerator, reaction auxiliary agent, or catalyst may be added to the substances A and B, respectively. Alternatively, a substance D such as reaction shortstop agent, secondary reactive substance, finishing agent, or modifier may be added to the reaction product between the substances A and B. Also, such addition can be applied for the reaction manner shown in Figure 18. More specifically, prior to the collision reaction between substances A and B, substances C and D such as surface active agent (dispersing agent etc.), reaction accelerator, reaction auxiliary agent, or catalyst may be added to the flows of the substances A and B, respectively. In addition, during the collision reaction between the reaction products AC and BD, substances E and F such as surface active agent (dispersing agent etc.), reaction accelerator, reaction auxiliary agent, or catalyst may be added to the flows of the substances AC and BD, respectively.. Further, substances G and H such as reaction shortstop agent, secondary reactive substance, finishing agent, or modifier may be added to the flow of the reaction product. Furthermore, as shown in Figures 15, 17, and 19, there may be additionally provided a pump P for pressurizing fluid containing particles of reaction product produced by the reaction shown in Figures 14, 16, and 18, and a dispersing apparatus N, e.g., a dispersing apparatus disclosed in Japanese Unexamined Patent Publication No. 9-201522, to thereby increase the stability of dispersion containing fine particles. Figure 20 shows still another collision reaction manner of the present invention. A reaction product of substances A and B is added with a surface active agent such as dispersing agent, a reaction shortstop agent, a second order substance, a finishing agent, or a modifier upstream and/or downstream of a pump P. The resultant is introduced into a dispersing apparatus N. This will more reliably prevent very fine reaction product particles from agglutinating. As means of supplying material substances may be selectively used a plunger pump, snake pump, diaphragm pump, centrifugal pump, or the like in consideration of the kind and flowability of substance. In the case of material substance in the form of gas or mist, a high pressure pump may be used. The flow rate of material substances before collision is controlled by adjusting the supplying pressure of the supply means and the section area of the flow passage. Also, the pressure of outflow of reaction product is controlled in a range of 0.1 to 300 MPa by adjusting the section area of the outflow passage. The flow in the outflow passage is substantially identical to the flow in the inflow passage in the case of material substances being in the state of liquid. In the case of at least one material substance being in the state of gas, however, the flow in the outflow passage is greatly different from or is remarkably smaller than the flow in the inflow passage because the gaseous substance converts into the liquid or solid state after reaction. Accordingly, the supplying pressure and flow section area are determined in consideration of a phase change after reaction. The high speed collision reaction occurs in the joining portion 7 where a high energy consequently generates. The inner surface of the joining portion 7 is subjected to severe abrasion. Therefore, the joining portion 7 is required to have a resistance to abrasion. Also, depending on characteristics of material substances and reaction product, the joining portion 7 is required to have a resistance to acid and alkaline chemicals, to solvents, and to heat. These requirements are satisfied by forming or depositing the chemically exposed portion of the joining portion 7 with durable materials, e.g., cemented carbides such as WC, abrasion-resistant ceramics such as zircon, alumina, boron carbide, sintered diamond, monocrystalline diamond. The high speed collision reactions of the present invention can be applied for a wide variety of substances which can be supplied under pressure, such as liquid substances, solutions, emulsions, suspensions, sol-gel liquids, gases, gases containing mists. As described above, according to the present invention, substances are collided in the joining portion 7 at a high speed to react with each other for a very short time. Reaction product is discharged out of the reactor through the outflow passage 9 without being held in the reaction system immediately after the reaction. This arrangement is highly advantageous in the case of producing very fine particles. More specifically, in the conventional batch-type method and agitation flow passage method, reaction between substances gradually proceeds. Accordingly, a variation in the reaction conditions such as substance concentration inevitably occurs as time passes, consequently causing aggregation of substances. On the other hand, in the method of the present invention, collision and reaction between substances are made in an extremely small space for a very short time, thus making it possible to produce very fine particles without forming aggregations. Furthermore, in the conventional batch-type method and the agitation flow passage method, it is difficult to control the temperature of the reaction system such as momentary increase and decrease in temperature because the amount of substance residing in the reaction system, the residence time of substance in the reaction system, the size and heat capacity of the reactor vary depending on each case. As a result, increases in equipment costs and energy costs are inevitable. On the other hand, in the method of the present invention, collision reaction is made in an extremely small space for a very short time. The temperature control of the small space can be more efficiently conducted by providing a heating device and a cooling device on the small space, thus assuring uniform reaction. Moreover, the method of the present invention can be more effectively applicable for the case where reaction product is liable to change its characteristics as the temperature varies. In the fine particles fields such as medicine industries, food industries, and electronic materials industries, contamination by foreign matters and bacterial causes the serious problem. The method of the present invention enables instantaneous reaction in a perfect closed space completely blocked from the atmosphere. Accordingly, the inventive method can more effectively and easily eliminate this problem by keeping the substance supplying system only from being contaminated. Also, in the medicine and food industries, it has been confirmed that sterilizing effect can be obtained by application of high pressure. Accordingly, the inventive method can additionally provide sterilization owing to the high pressure. In chemical reaction, the reaction efficiency between a gas and a liquid, and between a gas, a liquid, and a solid greatly depends on the solubility of gas in liquid. In other words, the reaction efficiency is increased by increasing the concentration of gas in liquid. In the inventive method, the solubility of gas in liquid can be easily increased by supplying substances under high pressure. This makes it possible to increase the efficiency of a reaction using a gaseous substance easily. The method of the present invention is applicable for a wide variety of reactions, such as liquid and liquid reaction, gas and liquid reaction, gas and gas reaction, by effectively utilizing the above-described advantageous features of the method in various industrial fields of producing medicines, foods, paints, inks, pigments, photosensitive materials, magnetic recording mediums, and the like. It should be noted that in the present invention, the term "liquid" include not only a substance in the form of liquid, a solution in which material substance is dissolved in an arbitrary solvent, an emulsion, a suspension, latex and the like. In particular, the method of the present invention is remarkably advantageous in reactions in which two or more liquid substances are reacted with each other to produce insoluble fine particles or emulsion. As described above, the inventive method can produce very fine particles of submicron by the high speed collision, particularly dispersion in which produced insoluble fine particles are dispersed in a solvent. Accordingly, the inventive method can produce an extremely stable dispersion liquid and emulsion more easily. The followings are examples of reactions which the method of the present invention can applied for. It is understood, however, that the present invention is not limited to these reactions. A reaction between an aqueous solution of CaCl 2 and an aqueous solution of NaCO 3 to produce fine particles of CaCO 3 ; A reaction between an aqueous solution of BaCl 2 and an aqueous solution of NaCO 3 to produce fine particles of BaCO 3 ; A reaction between an aqueous solution of BaCl 2 and an aqueous solution of H 2 SO 4 (or NaSO 4 ) to produce fine particles of BaSO 4 ; A reaction between an aqueous solution of ZnSO 4 and an aqueous solution of NaCO 3 to produce fine particles of ZnCO 3 ; A reaction between an aqueous solution of ZnSO 4 and an aqueous solution of Na 2 S x (or NH 4 S x ) to produce fine particles of ZnS; A reaction between an aqueous solution of Na 2 O · 3.3SiO 2 and an aqueous solution of H 2 SO 4 to produce SiO 2 in the form of sol; and A reaction between an aqueous solution of ZnSO 4 and an aqueous solution of NaOH to produce fine particles of Zn(OH) 2 . Fine particles of ZnO is obtained by decomposing Zn(OH) 2 by heat. The method of the present invention will be described in more detail by way of examples. It is to be understood, however, that various changes and modifications will be apparent to those skilled in the art. Therefore, unless otherwise such changes and modifications depart from the scope of the present invention, they should be construed as being included therein. Using the reactor shown in Figure 1, two substances were respectively supplied at a specified speed through the inflow passages, and were collided and reacted with each other at the joining portion. Reaction product was discharged through the outflow passage. The particle diameter of the reaction product was measured using a laser diffraction-type particle size distribution measuring device "SALD-2000A" manufactured by Shimazu Corporation. For comparison, another reaction was conducted using a batch-type agitation table reactor "AM-9" manufactured by Nippon Seiki Co., Ltd., and the particle diameter of the reaction product was measured in the same manner. Both the two inflow passages for supplying substances to the joining portion had a length of 7.5 mm and a diameter of 1.0 mm (i.e., a sectional area of 3.93 × 10 -7 m 2 ). The outflow passage for discharging reaction product from the joining portion had a length of 15 mm and a diameter of 1.8 mm (i.e., a sectional area of 1.27 × 10 -6 m 2 ). EXAMPLE 1 (relationship between the flow rate and the size of produced particle in production of barium sulfate) Test samples: barium chloride dihydrate (produced by Wako Pure Chemical Industries, Ltd.) : sodium sulfate (produced by Wako Pure Chemical Industries, Ltd.) : a surface active agent (a polycarboxylic acid-type surface active agent manufactured by Kao Corporation under trademark "Demol EP") : pure water Procedure of Test (1) 18 weight percent of barium chloride aqueous solution and 9- weight percent of sodium sulfate aqueous solution were respectively prepared. (2) 300g of the respective aqueous solutions prepared in step (1) were diluted with pure water to an amount of 400ml. (3) The respective aqueous solutions prepared in step (2) were supplied through the inflow passages under pressure, and were collided at the flow rates shown in Table 1 to obtain a dispersion liquid containing dispersed particles of barium sulfate. (4) The surface active agent was dissolved in the sodium sulfate aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. The test results are shown in Table 1 and Figure 6. Specifically, at the flow rate of less than 4 m/sec (Comparative Example), the barium sulfate had an average particle diameter as large as 3 µm or larger. Contrary to this, at the flow rate of 4m/sec or higher, the average particle diameter was as small as about 1 µm or smaller. At the flow rate of 7m/sec or higher, the average particle diameter was 0.5 µm or smaller. At the flow rate of 15m/sec or higher, the average particle diameter was 0.2 µm or smaller. Flow amount (ml/min) Flow rate (m/sec) Average particle diameter ( µ m) 10% particle diameter ( µ m) 90% particle diameter ( µ m) 25 1.1 4.18 0.36 32.16 50 2.1 3.39 0.29 12.89 100 4.2 1.13 0.23 4.21 200 8.5 0.36 0.16 1.04 300 12.7 0.29 0.11 0.44 400 17.0 0.14 0.06 0.27 500 21.2 0.12 0.05 0.20 600 25.5 0.07 0.03 0.16 700 29.7 0.04 0.02 0.13 EXAMPLE 2 (Production of barium sulfate) Test samples: barium chloride dihydrate (produced by Wako Pure Chemical Industries, Ltd.) : sodium sulfate (produced by Wako Pure Chemical Industries, Ltd.) a surface active agent (a polycarboxylic acid-type surface active agent manufactured by Kao Corporation under trademark "Demol EP") : pure water Procedure of Test A: Inventive method (1) 18 weight percent of barium chloride aqueous solution and 12 weight percent of sodium sulfate aqueous solution were respectively prepared. (2) 300g of the respective aqueous solutions prepared in step (1) were diluted with pure water to an amount of 400ml. (3) The respective aqueous solutions prepared in step (2) were supplied through the inflow passages under pressure, and were collided at the flow rate of 25.5 m/sec or 600 ml/sec to obtain a dispersion liquid containing dispersed particles of barium sulfate. (4) The surface active agent was dissolved in the sodium sulfate aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. B: Comparative method (batch-type agitation table reactor) (1) 18 weight percent of barium chloride aqueous solution and 12 weight percent of sodium sulfate aqueous solution were respectively prepared. (2) 150g of the respective aqueous solutions prepared in step (1) were taken out. (3) 100g of pure water was put in the reactor in which the respective aqueous solutions taken out in step (2) were simultaneously added into the reactor while driving an agitator at 5000 r.p.m., and maintained with each other for 30 minutes. (4) The surface active agent was dissolved in the sodium sulfate aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. The test results are shown in Table 2. It is found that the method of the present invention can produce barium sulfate in the form of extremely fine particles, as compared with the conventional batch-type agitation. Method Median diameter( µ m) 10% diameter/90% diameter ( µ m) Inventive method 0.09 0.05/0.11 Comparative method 1.06 0.39/2.53 EXAMPLE 3 (Production of barium carbonate) Test samples: barium chloride dihydrate (produced by Wako Pure Chemical Industries, Ltd.) : sodium carbonate (produced by Wako Pure Chemical Industries, Ltd.) : surface active agent (a polycarboxylic acid-type surface active agent manufactured by Kao Corporation under trademark "Demol EP") : pure water Procedure of Test A: Inventive method (1) 18 weight percent of barium chloride aqueous solution and 9 weight percent of sodium carbonate aqueous solution were respectively prepared. (2) 300g of the respective aqueous solutions prepared in step (1) were diluted with pure water to an amount of 400ml. (3) The respective aqueous solutions prepared in step (2) were supplied through the inflow passages under pressure, and were collided at the flow rate of 25.5 m/sec or 600 ml/sec to obtain a dispersion liquid containing dispersed particles of barium carbonate. (4) The surface active agent was dissolved in the sodium carbonate aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. B: Comparative method (batch-type agitation table reactor) (1) 18 weight percent of barium chloride aqueous solution and 9 weight percent of sodium carbonate aqueous solution were respectively prepared. (2) 150g of the respective aqueous solutions prepared in step (1) were taken out. (3) 100g of pure water was put in the reactor in which the respective aqueous solutions taken out in step (2) were simultaneously added into the reactor while driving an agitator at 5000 r.p.m., and maintained with each other for 30 minutes. (4) The surface active agent was dissolved in the sodium carbonate aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. The test results are shown in Table 3. It is found that the method of the present invention can produce barium carbonate in the form of extremely fine particles, as compared with the conventional batch-type agitation. Method Median diameter( µ m) 10% diameter/90% diameter ( µ m) Inventive method 0.19 0.13/0.28 Comparative method 2.93 0.41/5.61 EXAMPLE 4 (Production of calcium carbonate) Test samples: calcium chloride dihydrate (produced by Wako Pure Chemical Industries, Ltd.) : sodium carbonate (produced by Wako Pure Chemical Industries, Ltd.) : a surface active agent (a polycarboxylic acid-type surface active agent manufactured by Kao Corporation under trademark "Demol EP") : pure water Procedure of Test A: Inventive method (1) 16.5 weight percent of calcium chloride aqueous solution and 16 weight percent of sodium carbonate aqueous solution were respectively prepared. (2) 300g of the respective aqueous solutions prepared in step (1) were diluted with pure water to an amount of 400ml. (3) The respective aqueous solutions prepared in step (2) were supplied through the inflow passages under pressure, and were collided at the flow rate of 25.5 m/sec or 600 ml/sec to obtain a dispersion liquid containing dispersed particles of calcium carbonate. (4) The surface active agent was dissolved in the sodium carbonate aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. B: Comparative method (batch-type agitation table reactor) (1) 16.5 weight percent of calcium chloride aqueous solution and 16 weight percent of sodium carbonate aqueous solution were respectively prepared. (2) 150g of the respective aqueous solutions prepared in step (1) were taken out. (3) 100g of pure water was put in the reactor in which the respective aqueous solutions taken out in step (2) were simultaneously added into the reactor while driving an agitator at 5000 r.p.m., and maintained with each other for 40 minutes. (4) The surface active agent was dissolved in the sodium carbonate aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. The test results are shown in Table 4. It is found that the method of the present invention can produce calcium carbonate in the form of extremely fine particles, as compared with the conventional batch-type agitation. Method Median diameter( µ m) 10% diameter/90% diameter ( µ m) Inventive method 0.05 0.03/0.11 Comparative method 0.26 0.09/2.01 EXAMPLE 5 (Production of zinc sulfide) Test samples: zinc sulfate heptahydrate (produced by Wako Pure Chemical Industries, Ltd.) : sodium sulfide (produced by Wako Pure Chemical Industries, Ltd.) : a surface active agent (a polycarboxylic acid-type surface active agent manufactured by Kao Corporation under trademark "Demol EP") : pure water Procedure of Test A: Inventive method (1) 24 weight percent of zinc sulfate aqueous solution and 12 weight percent of sodium sulfide aqueous solution were respectively prepared. (2) 300g of the respective aqueous solutions prepared in step (1) were diluted with pure water to an amount of 400ml. (3) The respective aqueous solutions prepared in step (2) were supplied through the inflow passages under pressure, and were collided at the flow rate of 25.5 m/sec or 600 ml/sec to obtain a dispersion liquid containing dispersed particles of zinc sulfide. (4) The surface active agent was dissolved in the sodium sulfide aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. B: Comparative method (batch-type agitation table reactor) (1) 24 weight percent of sodium sulfate aqueous solution and 12 weight percent of sodium sulfide aqueous solution were respectively prepared. (2) 150g of the respective aqueous solutions prepared in step (1) were taken out. (3) 100g of pure water was put in the reactor in which the respective aqueous solutions taken out in step (2) were simultaneously added into the reactor while driving an agitator at 5000 r.p.m., and maintained with each other for 25 minutes. (4) The surface active agent was dissolved in the sodium sulfide aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. The test results are shown in Table 5. It is found that the method of the present invention can produce zinc sulfide in the form of extremely fine particles, as compared with the conventional batch-type agitation. Method Median diameter( µ m) 10% diameter/90% diameter ( µ m) Inventive method 0.07 0.03/0.09 Comparative method 1.40 0.31/4.52 EXAMPLE 6 (Production of zinc hydroxide and zinc oxide) Test samples: zinc sulfate heptahydrate (produced by Wako Pure Chemical Industries, Ltd.) : sodium hydroxide (produced by Wako Pure Chemical Industries, Ltd.) : a surface active agent (a polycarboxylic acid-type surface active agent manufactured by Kao Corporation under trademark "Demol EP") : pure water Procedure of Test A: Inventive method (1) 24 weight percent of zinc sulfate aqueous solution and 12 weight percent of sodium hydroxide aqueous solution were respectively prepared. (2) 300g of the respective aqueous solutions prepared in step (1) were diluted with pure water to an amount of 400ml. (3) The respective aqueous solutions prepared in step (2) were supplied through the inflow passages under pressure, and were collided at the flow rate of 25.5 m/sec or 600 ml/sec to obtain a dispersion liquid containing dispersed particles of calcium carbonate. (4) The surface active agent was dissolved in the sodium hydroxide aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. B: Comparative method (batch-type agitation table reactor) (1) 24 weight percent of zinc sulfate aqueous solution and 12 weight percent of sodium hydroxide aqueous solution were respectively prepared. (2) 150g of the respective aqueous solutions prepared in step (1) were taken out. (3) 100g of pure water was put in the reactor in which the respective aqueous solutions taken out in step (2) were simultaneously added into the reactor while driving an agitator at 5000 r.p.m., and maintained with each other for 30 minutes. (4) The surface active agent was dissolved in the sodium hydroxide aqueous solution in such a manner that its concentration becomes 0.1 weight percent in the dispersion liquid after the reaction. The dispersion liquids produced by the inventive method and the comparative method were respectively dried under a reduced pressure while being agitated, and further dried at 120°C for one hour to obtain fine particles of zinc oxide. The size of particles of zinc hydroxide contained in the dispersion liquid and the size of particles of zinc oxide obtained by the heat-decomposition are shown in Table 6. It is found that the method of the present invention can produce zinc hydroxide and zinc oxide in the form of extremely fine particles, as compared with the conventional batch-type agitation. Method Median diameter ( µ m) 10% diameter/90% diameter ( µ m) Zinc hydroxide Inventive method 0.07 0.04/0.12 Comparative Method 0.23 0.11/3.42 Zinc oxide Inventive method 0.05 0.03/0.10 Comparative method 0.14 0.07/2.92 As described above, in the method of the present invention, two or more substances having reactivity with each other are supplied through different inflow passages to a joining portion. In the joining portion, the substances are collided against each other at a flow rate of 4 m/sec or higher to cause reaction with each other for a short time. Accordingly, uniform reaction can be caused at high efficiency. In the case of a reaction producing an insoluble reaction product, such as fine particles, emulsion, latex, also, the method of the present invention is advantageous in that the high speed collision generates great collision energy, and then turbulence and shearing forces, thus preventing aggregation. In other words, the inventive method can produce dispersion liquid containing very fine particles of submicron at a remarkably high efficiency. Further, the method of the present invention can maintain the reaction system under constant conditions or avoid such physical and chemical change as a variation in the amount and concentration of reactive substances, a variation in pH. Furthermore, the method of the present invention can provide sterilizing effects because of the high speed collision. Moreover, the reaction chamber where the high collision reaction occurs is very small. Accordingly, the reaction temperature can be more easily and accurately controlled by providing heating and cooling device on the reaction chamber.

Claims: A method of reacting two or more reactive substances comprising joining together first and second collinear walled inlet passages (5a, 5b, 6a, 6b) and a walled outlet passage (8, 9) to form a collision enclosure (7) defined by the joined walls of said passages; introducing at least one reactant along said first inlet passage (5a, 6a) and at least one other reactant along said second inlet passage (5b, 6b) into said collision enclosure (7); effecting a collision between said two introduced reactants within said collision enclosure (7) at a flow rate of 4 m/sec or higher and thereby causing a chemical reaction and producing fine particles as a reaction product; and removing the reaction product from the collision enclosure (7) via said outlet passage (8, 9). A method according to claim 1, wherein said introducing step and said removing step is effected continuously and non-cyclically. A method according to claim 1 or 2, wherein the reactive substances have the form of liquid and/or gas. A method according to claims 1 to 3, wherein the reactive substances are inorganic compounds dissolved in specified solvents, respectively. A method according to claim 4, wherein a reaction product of the reaction is insoluble in the specified solvents. A method according to one or more of claims 1 to 5, wherein the flows of the reactive substances are collided against one another along a line. A method according to claims 1 to 6, wherein the flows of the substances are collided at a flow rate of 7 m/sec or higher. A method according to one or more of claims 1 to 7 further comprising the step of adding a dispersing agent before and/or after the collision reaction.

Inventors: MITAKE KAZUTOSHI, MIYAKE FUMINORI, TODA MEGUMU, YASUDA FUMIO, YAZAKI TATSUO, MITAKE, KAZUTOSHI, MIYAKE, FUMINORI, TODA, MEGUMU, YASUDA, FUMIO, YAZAKI, TATSUO, Mitake, Kazutoshi, c/o Genus Corporation, Miyake, Fuminori, c/o Genus Corporation, Toda, Megumu, c/o Hakusui Chem. Ind., Ltd., Yasuda, Fumio, c/o Genus Corporation, Yazaki, Tatsuo, c/o Hakusui Chem. Ind., Ltd.
Applicants: GENUS CORP, HAKUSUI TECH CO LTD, GENUS CORPORATION, HAKUSUI TECH CO., LTD.
Application year: 1997
Main classification: B01F5
IPC codes: B01F5