JP5660605B2 - Method and apparatus for continuous mixing of high pressure carbon dioxide and high viscosity organic fluid - Google Patents

Description

  The present invention relates to a processing method and apparatus for a high-viscosity organic fluid by continuous mixing of high-pressure carbon dioxide, and more specifically, the present invention relates to a high-viscosity containing paint or molten resin by continuous mixing of high-pressure carbon dioxide. A method for processing an organic fluid, which relates to a process and apparatus for continuously mixing the high-viscosity organic fluid and high-pressure carbon dioxide to suppress intermittent supply of high-pressure carbon dioxide and stabilize the supply flow rate It is. The present invention is a new high-viscosity organic material that can replace the existing high-viscosity organic fluid processing technology that uses a large amount of organic solvent and can dramatically reduce the use of organic solvent. New technology and new products related to processing methods and equipment for high-viscosity organic fluids by low pressure, low environmental load, high-pressure carbon dioxide continuous mixing. It is.

  Conventionally, a spraying technique is widely used as a method for coating a polymer, and the coating technique is classified into a film forming technique or a atomizing technique depending on a final product form. Many of the polymers have poor fluidity as a single substance, and are dissolved in an organic solvent called a true solvent to ensure fluidity as a high viscosity organic fluid. Even in this state, since the organic fluid often has a high viscosity, an organic solvent is similarly added as a diluting solvent to reduce the viscosity to a sprayable level, and continuous spraying is performed. Typical examples of this technique are spray coating and spray coating.

In recent years, as a replacement for organic solvents, a process has been proposed in which high-pressure CO ₂ containing supercritical conditions is mixed with high-viscosity organic fluids to reduce the viscosity of organic fluids, and paint or coat from high-pressure conditions. (Patent Document 1, Non-Patent Document 1). In this system, high-pressure CO ₂ has the same solvent characteristics as an organic solvent. Therefore, in spray coating and spray coating, paint and high-pressure CO ₂ are continuously supplied, and about 30% of the paint. We have proposed a low environmental load type coating device that mixes and dissolves high-pressure CO ₂ to a degree to lower the viscosity of the paint and sprays it from a high-pressure environment to atmospheric pressure. The paint shown here includes, in addition to paints used in general painting, a wide range of organic polymers including organic and inorganic substances alone or those diluted with oligomers or organic solvents thereof.

Similarly, a high-viscosity organic fluid obtained by melting a resin is supplied at a high pressure, and high-pressure CO ₂ is dissolved in the high-viscosity organic fluid containing the molten resin to reduce the viscosity. A process for producing fine particles of resin by spraying to atmospheric pressure has been proposed (Patent Document 2, Non-Patent Document 2-4). This method is called PGSS ^™ (Particle from Gas-Saturated Solutions). Initially, a method of spraying a molten resin in which high-pressure CO ₂ was saturated in an autoclave to atmospheric pressure was proposed. However, in recent years, there has been reported a system for continuously supplying a molten resin and high-pressure CO ₂ (Non-Patent Document 5).

Both of these techniques are processes in which high-pressure CO ₂ is dissolved in a high-viscosity organic fluid containing paint or molten resin as a viscosity-reducing medium and sprayed from a high-pressure environment to atmospheric pressure. In these processes, decompression occurs in the process of atmospheric release from the spray nozzle, and most of the CO ₂ is desorbed from the liquid. Further, CO ₂ is also dissolved in the droplets ejected into the atmosphere, and it is considered that the effect of miniaturization is caused by the vaporization of these.

However, these processes are processes that use a large amount of an organic solvent in the existing methods in both technologies. If these processes can be converted into a spraying process using high-pressure CO ₂ , the use of an organic solvent is required. The amount can be drastically reduced, and in particular, since spray coating and spray coating are used in so many fields, it is expected to be widely applied and deployed. Thus, it is possible in the art to develop new process technologies for spraying, film formation, or atomization with high pressure CO ₂ that can dramatically reduce the amount of such organic solvents used. It was strongly requested.

JP-A-1-258770 Weidner, E .; , Knez, Z and Novak, Z. , 1994, European Patent No. 940079 (Japanese Patent No. 3510262)

Suzuki et al., “Paint Engineering”, Vol. 44, no. 7, 230-237 (2009) Sencar-Bozic, P.A. Srcic, S .; , Knez, Z. and Kerc, J.A. , “Improvement of Nifdition Dissolution charactaristics using supercritical CO2,” Int. J. et al. Pharm. 148, 123-130 (1997) Kerc, J .; Srcic, S .; , Knez, Z. and Sencar-Bozic, P.A. "Micronization of drugs using supercritical carbon dioxide", Int. J. et al. Pharm. 182, 33-39 (1999) Weidner, E .; , “High pressure micronization for food applications”, J. et al. Supercrit. Fluids 47, 556-565 (2009) Weidner, E .; Petermann, M .; and Knez, Z .; , “Multifunctional composites by high-pressure spray processes”, Curr. Opin. Solid State Mat. Sci. 7,385-390 (2003)

  In such a situation, in view of the above-described conventional technology, the present inventors can replace high-viscosity organic fluid processing technology by an existing method using a large amount of organic solvent. As a result of intensive research aimed at developing a processing technology for new high-viscosity organic fluids that makes it possible to dramatically reduce their use, new high-viscosity organic fluids by continuous high-pressure carbon dioxide mixing The present inventors have succeeded in establishing a processing method and completed the present invention.

  An object of this invention is to provide the processing method of the high-viscosity organic fluid containing a coating material or molten resin by continuous mixing of high-pressure carbon dioxide. Another object of the present invention is to provide a continuous mixing process and apparatus for the high-viscosity organic fluid and high-pressure carbon dioxide for suppressing intermittent supply of high-pressure carbon dioxide and stabilizing the supply flow rate. It is what. Another object of the present invention is to provide a process for spraying the high viscosity organic fluid from a high pressure environment by continuous mixing of the high pressure carbon dioxide, a process for forming a film, and a process for atomization. is there.

The present invention for solving the above-described problems comprises the following technical means.
(1) A high-viscosity organic material comprising a high-pressure process in which high-pressure organic fluid containing paint or molten resin and high-pressure carbon dioxide, which is continuously supplied, are mixed in a mixer in a mixing unit. In the method of processing a fluid,
In the high-pressure carbon dioxide supply line, a primary pressure control valve is provided upstream of the mixing unit, and the set pressure of the primary pressure control valve is set to the pressure of the mixing unit, and the fluctuating pressure value generated in the line after the mixing unit is set. By setting the pressure higher than the applied pressure, the intermittent supply of high-pressure carbon dioxide is suppressed, and the supply flow rate is stabilized. Processing method.
(2) In the high pressure process,
The processing method of the high-viscosity organic fluid according to (1), wherein the set pressure of the primary pressure control valve is set to a high pressure in the range of 1 to 5 MPa of the pressure of the mixing unit.
(3) In the above high pressure process,
The processing method with the high-viscosity organic fluid according to (1) or (2), wherein the internal volume of the pipe from the primary pressure control valve to the mixer is minimized.
(4) In the high pressure process,
A mechanism that gives a pressure loss of the metering needle valve or capillary tube downstream of the primary pressure control valve is provided, and the controllability of the primary pressure control valve is improved when the supply flow rate of high-pressure carbon dioxide is low. The processing method of the high-viscosity organic fluid according to any one of (1) to (3), which is improved.
(5) A high-viscosity organic fluid comprising a high-pressure process in which high-pressure organic fluid containing paint or molten resin and high-pressure carbon dioxide, which is continuously supplied, are mixed in a mixer in a mixing section. In the method of processing a fluid,
In the high viscosity organic fluid supply line, a secondary pressure control valve is provided upstream of the mixing section, and the flow rate of the high viscosity organic fluid is substantially adjusted to control the pressure of the mixer to be constant. A method for processing a high viscosity organic fluid by continuous mixing of high pressure carbon dioxide.
(6) In the above high pressure process,
The high-viscosity organic fluid supply line is provided with a relief valve upstream of the secondary pressure control valve installed upstream of the mixing section to avoid an increase in high-pressure pump discharge pressure. Viscosity organic fluid processing method.
(7) In the above high pressure process,
In the case of a high-viscosity organic fluid containing a molten resin, it has a primary pressure control valve for high-pressure carbon dioxide before mixing, and the line after mixing the high-viscosity organic fluid and high-pressure carbon dioxide has a 1 The continuous mixing method of the high-viscosity organic fluid and high-pressure carbon dioxide according to any one of (1) to (4), wherein a secondary pressure control valve is provided.
(8) In the above processing process,
The processing method of the high-viscosity organic fluid according to any one of (1) to (7), wherein the high-viscosity organic fluid is processed in a process of spraying and atomizing the high-viscosity organic fluid from a high-pressure environment.
(9) In the above processing process,
The processing method of the high-viscosity organic fluid according to any one of (1) to (7), wherein the high-viscosity organic fluid is processed by a process of forming a film of the high-viscosity organic fluid.
(10) In the above high pressure process,
The high-viscosity organic fluid according to any one of (1) to (9), wherein the mixer for continuously mixing the high-viscosity organic fluid and the high-pressure carbon dioxide is a high-pressure micromixer using a microchannel. Processing method.
(11) In the high pressure process,
The method for processing a high-viscosity organic fluid according to (10), wherein the high-pressure micromixer is a multistage division type high-pressure micromixer, a center collision micromixer, a T-shaped micromixer, or a swirl mixer.
(12) A continuous mixing apparatus having a high-pressure mixing unit that mixes a high-viscosity organic fluid containing paint or molten resin continuously supplied with high pressure and high-pressure carbon dioxide supplied continuously in a mixer. ,
The high pressure carbon dioxide supply line has a primary pressure control valve upstream of the mixing section, and the set pressure of the primary pressure control valve is changed to the pressure of the mixing section and the fluctuating pressure value generated in the line after the mixing section By setting the pressure higher than the pressure added, the intermittent supply of high-pressure carbon dioxide is suppressed and the supply flow rate is stabilized. Continuous mixing device.
(13) In the above device,
The continuous mixing apparatus according to (12), wherein a volume in the pipe from the primary pressure control valve to the mixer is minimized.
(14) In the above device,
The continuous mixing device according to (12), wherein a mechanism for imparting a pressure loss of the metering needle valve or the capillary tube is provided downstream of the primary pressure control valve.
(15) A continuous mixing apparatus having a mixing unit that mixes a high-viscosity organic fluid containing paint or molten resin continuously supplied with high pressure and high-pressure carbon dioxide supplied continuously in a mixer,
In the high-viscosity organic fluid supply line, there is a secondary pressure control valve upstream of the mixing section, and the pressure of the mixer is controlled to be constant by adjusting the flow rate of the high-viscosity organic fluid substantially. A continuous mixing apparatus for high-viscosity organic fluid and high-pressure carbon dioxide, characterized in that
(16) In the above device,
In the high viscosity organic fluid supply line, the relief valve is provided upstream of the secondary pressure control valve installed upstream of the mixing unit, so as to avoid an increase in the discharge pressure of the high pressure pump. Continuous mixing equipment.
(17) In the above device,
The continuous mixing apparatus according to (12) to (16) above, wherein a primary pressure control valve for a fluid after mixing is provided in a line after mixing high-pressure carbon dioxide.
(18) In the above device,
The continuous mixing apparatus according to any one of (12) to (17), wherein the mixer for continuously mixing high-pressure carbon dioxide is a high-pressure micromixer using a microchannel.
(19) In the above device,
The continuous mixing apparatus according to (18), wherein the high-pressure micromixer is a multi-channel divided type high-pressure micromixer, a center collision micromixer, a T-shaped micromixer, or a swirl mixer.

Next, the present invention will be described in more detail.
The present invention provides a high-viscosity process including a high-pressure process in which a high-viscosity organic fluid containing paint or molten resin that is continuously supplied at high pressure and high-pressure carbon dioxide that is also continuously supplied are mixed in a mixer in a mixer. In the organic fluid processing method, a primary pressure control valve is provided upstream of the mixing unit in the high-pressure carbon dioxide supply line, and the set pressure of the primary pressure control valve is set to the pressure of the mixing unit after the mixing unit. By setting the pressure higher than the pressure obtained by adding the fluctuating pressure value generated in this line, intermittent supply of high-pressure carbon dioxide is suppressed, and the supply flow rate is stabilized.

  In addition, the present invention provides a continuous mixing having a high-pressure mixing unit that mixes a high-viscosity organic fluid containing paint or molten resin continuously supplied with high pressure and high-pressure carbon dioxide supplied continuously in a mixer. A high pressure carbon dioxide supply line having a primary pressure control valve upstream of the mixing unit, and the set pressure of the primary pressure regulating valve is set to the pressure of the mixing unit and the line after the mixing unit By setting the pressure higher than the pressure obtained by adding the fluctuating pressure value generated in step 5, the intermittent supply of high-pressure carbon dioxide is suppressed, and the supply flow rate is stabilized.

Here, the background that led to the development of the present invention will be specifically described. Generally, a high-viscosity organic fluid containing a paint or a molten resin has a higher viscosity than CO ₂ . Many of such high-viscosity organic fluids have density changes when the pressure is changed at an arbitrary temperature, for example, from room temperature to about 40 ° C. for coating and from about 100 to 300 ° C. for atomization of molten resin. Is very small compared to CO ₂ . Furthermore, the supply amount of CO ₂ is usually as low as about 30 wt% with respect to the supply amount of the high viscosity organic fluid. As described above, in the mixing of two kinds of fluids of high viscosity organic fluid and carbon dioxide such as high viscosity organic fluid and carbon dioxide, the basic problem is stable and continuous. In general, it was difficult to perform fluid mixing.

Here, in order to further explain in accordance with a specific example, FIG. 1 shows an outline of an existing apparatus used for carbon dioxide coating as an example of a mixing process of a high-viscosity organic fluid and high-pressure CO ₂ with respect to spray coating. Show. As shown in FIG. 1, the paint is supplied from a paint pump and heated to a predetermined temperature in a paint heater. Control of the process pressure P4 is determined by the spray nozzle hole diameter, fluid flow rate, and viscosity. CO ₂ is supplied by a CO ₂ pump, and is similarly heated to a predetermined temperature in a heater. Each fluid is mixed by the mixer MX-1. The CO ₂ flow rate is about 30 wt% with respect to the paint flow rate. In the past reports of painting, a static mixer is used as this mixer (Patent Document 1).

FIG. 2 shows an outline of an existing apparatus used for the CO ₂ mixing, spraying and atomizing technology to a high viscosity organic fluid containing a molten resin. As shown in FIG. 2, the pellet-shaped resin is put into a resin hopper and heated and melted with an extruder. A high-viscosity organic fluid containing a molten resin is quantitatively supplied with a gear pump under high-pressure conditions. The line through which the high-viscosity organic fluid containing the molten resin passes is heat traced, including after CO ₂ mixing. CO ₂ is supplied by a CO ₂ pump, heated to an arbitrary temperature, and then mixed with a high-viscosity organic fluid containing a molten resin by a mixer MX-1. The CO ₂ flow rate is about 30 wt% with respect to the high viscosity organic fluid flow rate containing the molten resin. This process has a process of obtaining fine particles by spraying the fluid after mixing to atmospheric pressure. In the past reports, a static mixer is also used for the mixer of this process (Non-Patent Document 5).

The static mixer performs mixing by dividing the flow path into multiple stages, and is widely used for relatively high flow rate cases. However, the rapid mixing performance is not so good. If the mixed state is insufficient, the mixture after the fluid, for example, the upper CO ₂ is lower and the organic fluid is seen to flow to form two phases, or, CO ₂ is mixed, the viscosity In some cases, an organic fluid having a reduced viscosity and an organic fluid in which the mixing of CO ₂ is poor and the viscosity is not lowered flow alternately. In the case of a spraying process, this phenomenon becomes an intermittent flow due to discontinuity of fluid properties, resulting in fluctuations in the process pressure, and as a result, stable spraying is not performed.

FIG. 3 shows the relationship between the CO ₂ supply pressure P - 1, the solution supply pressure P - 2, and the process pressure P - 4 when the spray process of FIG. 1 is taken as an example. When the viscosity of the high-viscosity organic fluid is high, the difference in viscosity from CO ₂ becomes large. Therefore, the process pressure fluctuation is greatly affected by the mixing performance of the mixer. As shown in FIG. 3, when the process pressure fluctuates, the solution supply pressure having a high viscosity easily follows the fluctuation, but CO ₂ has a low flow rate and a large amount of density change with respect to the pressure at a constant temperature. Therefore, it takes time to boost the voltage. For example, when the process pressure fluctuated from 12 MPa to 14 MPa under the condition of 35 ° C., the organic fluid was toluene and the pressure increase rate with CO ₂ was compared.

The density change between 12 MPa and 14 MPa at a constant temperature of 35 ° C. is 0.00151 g / cc for toluene and 0.03434 g / cc for CO ₂ , and CO ₂ is 23 times the density change for toluene. You can see that it ’s big. Furthermore, the CO ₂ supply flow rate is about 30 wt% with respect to the toluene flow rate. Therefore, CO ₂ requires 76 times the time to increase the same volume from 12 MPa to 14 MPa with respect to toluene.

In order to explain in accordance with a specific example, the internal volume of the pipes to the respective toluene and CO ₂ mixers is 100 cc, the toluene flow rate is 30 g / min, the CO ₂ flow rate is 9 g / min (30 wt% of the toluene flow rate), and To do. The pressurization time from 12 MPa to 14 MPa at 35 ° C. is 0.3 s for toluene and 22 s for CO ₂ . Therefore, toluene substantially follows the process pressure fluctuation, and a flow rate of 30 g / min is continuously supplied to the mixer and the subsequent parts. However, CO ₂ cannot follow process pressure fluctuations because it takes longer to pressurize with toluene.

That, CO ₂ supply pressure is lower than the process pressure interval, the boosting of the volume of the CO ₂ pump to the mixer, CO ₂ supplied from the pump is used, after the mixer, CO ₂ does not flow out. When the process pressure drops to the same pressure as the CO ₂ supply pressure, CO ₂ is supplied after the mixer. When the process pressure starts to increase again, the CO ₂ pressure increase rate cannot follow the process pressure fluctuation, and CO ₂ does not flow after the mixer, and is consumed for increasing the volume from the pump to the mixer.

By causing such a phenomenon, in the fluid after the mixer, a region in which CO ₂ is dissolved and a region in which CO ₂ is not dissolved are formed intermittently, and the process pressure P - 4 varies. However, the spray state becomes unstable. Therefore, in the present invention, in order to avoid such a phenomenon, a new technique for suppressing intermittent supply of high-pressure carbon dioxide and stabilizing the supply flow rate by adopting the following configuration is established. did.

  That is, the present invention is a high-pressure process in which a high-viscosity organic fluid containing paint or molten resin that is continuously supplied at high pressure and high-pressure carbon dioxide that is also continuously supplied are mixed in a mixer in a mixer. In the high-pressure carbon dioxide supply line, a primary pressure control valve is provided upstream of the mixing unit, and the set pressure of the primary pressure control valve is set to the pressure of the mixing unit, and the fluctuating pressure value generated in the line after the mixing unit is set. By setting the pressure higher than the applied pressure, intermittent supply of high-pressure carbon dioxide is suppressed, and the supply flow rate is stabilized.

  In the present invention, in the high pressure process, the set pressure of the primary pressure control valve is controlled to a high pressure in the range of 1 to 5 MPa, preferably 1 to 2 MPa of the pressure in the mixing section, and in the high pressure process, Minimize the internal volume of the pipe from the primary pressure control valve to the mixer as much as possible, and in the high-pressure process, a pressure loss such as a metering needle valve or capillary tube is provided downstream of the primary pressure control valve. It is necessary to provide a mechanism for imparting, and particularly to improve the controllability of the primary pressure control valve when the supply flow rate of high-pressure carbon dioxide is low.

  Further, the present invention provides a high-viscosity organic fluid in a high-pressure process in which the high-viscosity organic fluid that is continuously supplied at a high pressure and high-pressure carbon dioxide that is also continuously supplied are mixed in a mixer in a mixing section. In the supply line, a secondary pressure control valve is provided upstream of the mixing unit, and the flow rate of the high-viscosity organic fluid is substantially adjusted to control the pressure of the mixer to be constant. Is.

  In the present invention, in the high-pressure process, a relief valve is provided upstream of the secondary pressure control valve installed upstream of the mixing section in the high-viscosity organic fluid supply line to avoid an increase in discharge pressure of the high-pressure pump. In the high-pressure process, in the case of a high-viscosity organic fluid containing a molten resin, a primary pressure control process of high-pressure carbon dioxide before mixing is provided, and the high-viscosity organic fluid and high-pressure carbon dioxide are mixed. In the subsequent line, it is necessary to provide a primary pressure control valve for the fluid after mixing, and in the high pressure process described above, the continuous mixing method of the high viscosity organic fluid and high pressure carbon dioxide is a high viscosity organic fluid. It is applied to the process of spraying and atomizing from a high pressure environment, or the process of forming a film.

  In the present invention, the paint widely includes any paint used in general painting, organic polymers including organic and inorganic, and those diluted with oligomers or organic solvents thereof, and a molten resin and Means that an organic fluid obtained by melting a general resin in high-pressure carbon dioxide is widely included. In the present invention, in the high-pressure process, the mixer for continuously mixing the high-viscosity organic fluid and the high-pressure carbon dioxide is a high-pressure micromixer using a microchannel. It is preferably a multistage division type high pressure micromixer, a center collision type micromixer, a T-shaped micromixer, or a swirl mixer.

  Next, the apparatus used in the above-described process will be described in detail. The present invention relates to a high-viscosity organic fluid containing paint or molten resin that is continuously supplied with high pressure, and high-pressure carbon dioxide that is continuously supplied. Is a continuous mixing apparatus having a high pressure mixing section that mixes in a mixer, having a primary pressure control valve upstream of the mixing section in a high pressure carbon dioxide supply line, Set the set pressure to a pressure larger than the pressure of the mixing section plus the fluctuating pressure value generated in the line after the mixing section, thereby suppressing intermittent supply of high-pressure carbon dioxide and reducing the supply flow rate. It is characterized by being stabilized.

  In the present invention, the internal volume of the pipe from the primary pressure control valve to the mixer is minimized in the apparatus, and the metering needle valve is disposed downstream of the primary pressure control valve in the apparatus. Alternatively, it is necessary to provide a mechanism for imparting pressure loss such as a capillary tube.

  Further, the present invention is a continuous mixing apparatus having a mixing section for mixing a high-viscosity organic fluid containing paint or molten resin continuously supplied with high pressure and high-pressure carbon dioxide supplied continuously in a mixer. The high-viscosity organic fluid supply line has a secondary pressure control valve upstream of the mixing section, and substantially adjusts the flow rate of the high-viscosity organic fluid to reduce the pressure of the mixer. It is characterized by being controlled to be constant.

  In the present invention, in the above apparatus, a relief valve is provided upstream of the secondary pressure control valve installed upstream of the mixing unit in the high viscosity organic fluid supply line so as to avoid an increase in the discharge pressure of the high pressure pump. In the above apparatus, a primary pressure control valve for the fluid after mixing is provided in the line after mixing the high pressure carbon dioxide, and in the above apparatus, a mixer for continuously mixing the high pressure carbon dioxide is provided. A high-pressure micromixer using a microchannel, and in the above apparatus, the high-pressure micromixer is a multistage divided-channel high-pressure micromixer, a center collision micromixer, a T-shaped micromixer, or a swirl mixer Is required.

  The present invention relates to a method for processing a high-viscosity organic fluid containing a paint or a molten resin, in particular, a process of continuously spraying a high-viscosity organic fluid containing a paint from a high-pressure environment into the atmosphere by continuous mixing of high-pressure carbon dioxide. And a new process and apparatus applied to a process in which a high-viscosity organic fluid containing a molten resin is continuously sprayed, continuously formed, or continuously atomized from a high-pressure environment by continuous mixing of high-pressure carbon dioxide. Useful. The present invention can be widely applied without being limited to the type of paint or molten resin as long as continuous mixing of high-pressure carbon dioxide is possible. Specific conditions and specific shapes of the devices The structure can be set and designed as appropriate in implementing the structure.

  The present invention has a characteristic part in a high-pressure process by continuous high-pressure carbon dioxide mixing, and the process itself of the spraying operation, atomization operation, and film forming operation following the high-pressure process appropriately uses conventional methods. Any existing means or new means and conditions used in the course of spraying, atomization and film-forming operations can be used as appropriate. The present invention includes spraying, atomization, and film forming operations following the high-pressure process, and product forms produced by these operations, including all operations and product forms. There is no particular limitation.

The present invention has the following effects.
(1) According to the present invention, in the process of mixing a high-viscosity organic fluid and high-pressure carbon dioxide, when mixing two fluids having a difference in viscosity and a difference in flow rate, even if the pressure fluctuation of the process occurs, Since the pressure section is provided in the slow carbon dioxide supply line, high-pressure carbon dioxide can be stably supplied.
(2) Therefore, fluctuations in process pressure can be minimized, and process stabilization is achieved.
(3) In the processing method of the high-viscosity organic fluid containing paint or molten resin, intermittent supply of high-pressure carbon dioxide can be suppressed and the supply flow rate can be stabilized.
(4) A new high-viscosity organic material that can replace the existing high-viscosity organic fluid processing technology that uses a large amount of organic solvent and can dramatically reduce the use of organic solvent. Fluid processing techniques can be provided.
(5) It is possible to provide a new technology / new product relating to a new processing method and apparatus for a high-viscosity organic fluid that is low in environmental load and has low emission of organic solvent and is continuously mixed with high-pressure carbon dioxide.
(6) Since the high pressure carbon dioxide continuously supplied is stably supplied even at a low flow rate, the organic fluid condition after mixing is stable, and atomization, spraying, film formation In any case, the performance is stable.

The outline of the existing carbon dioxide coating equipment is shown. CO ₂ mixture to an existing molten resin shows an apparatus outline of the spray-atomization technology. Shows process pressure variation. An outline of an embodiment of a carbon dioxide painting device is shown. The driving trend by the existing method is shown. Fig. 2 shows a driving trend according to the invention. It shows a schematic embodiment of a spray-atomization technique by CO ₂ mixed into the molten resin.

  EXAMPLES Next, although this invention is demonstrated concretely based on an Example, this invention is not limited at all by the following Examples.

  An example of a preferred embodiment of the present invention is shown below. FIG. 4 shows an embodiment relating to spray coating. As shown in FIG. 4, the primary pressure control valve PCV-2 was provided in the high-pressure carbon dioxide supply line, and the internal volume of the line from the primary pressure control valve PCV-2 to the mixer MX-1 was minimized. The set pressure of PCV-2 was about 1 to 5 MPa, more preferably about 1 to 2 MPa higher than the pressure P-4 in the mixer. The process pressure P-4 varies due to the viscosity change of the fluid after mixing the high viscosity organic fluid and carbon dioxide, the stable solubility of carbon dioxide, and the like. A pressure difference equal to or greater than the fluctuating pressure width was secured upstream of PCV-2, and a pressure section was provided in the carbon dioxide supply line.

  Although the fluctuation shown in FIG. 3 is caused by the pressure fluctuation, the density difference is large, and the volume that the low flow rate of carbon dioxide needs to be pressurized is minimized, and by providing the pressure section, the PCV-2 is more effective. The pressure increase time of the upstream volume is not required. Since the viscosity of high-pressure carbon dioxide is low, the pipe from PCV-2 to the mixer is, for example, a thin tube of 1/16 inch, etc., and the volume is minimized by installing PCV-2 close to the mixer did.

The supply line on the high-viscosity organic fluid side is provided with a secondary pressure control valve shown in PCV-4 so as to have a function of keeping the pressure in the mixing unit constant. In the spraying process, it has been found that spraying can be stabilized by spraying at a constant pressure. Specifically, only the high-viscosity organic fluid was supplied, and the pressure of the mixing part was adjusted to 10 MPa with PCV-4. Next, when CO ₂ was supplied, the flow rate after mixing increased, but the viscosity decreased, so the pressure loss decreased. Therefore, to obtain the same process pressure, i.e. the spray pressure, the flow rate is increased.

  This is because the secondary pressure control valve is provided in the line of the high-viscosity organic fluid, so that the flow rate is increased or decreased in order to keep the pressure in the mixing unit constant. Although not shown, it is preferable that the high-viscosity organic fluid and the high-pressure carbon dioxide have a configuration capable of grasping the mass flow rate. A means for grasping the flow rate is not limited, but a Coriolis mass flow meter, a thermal flow meter, a differential pressure meter flow meter, an area flow meter, or the like was used.

  In addition, a high-pressure micromixer using microchannels was used as a mixer, and a high-speed organic fluid and high-pressure carbon dioxide were stably and rapidly mixed. Specifically, as the high-pressure micromixer, a multistage divided-channel high-pressure micromixer, a center collision micromixer, a T-shaped micromixer, and a swirl mixer were used.

In FIG. 5, the operation data of the carbon dioxide coating apparatus by the existing method are shown. As shown in FIG. 5, the pre-mixing CO ₂ pressure P- 1 is lower than the post-mixing pressure P- 4 when the pressure rises. In this section, the supplied CO ₂ is consumed for boosting and is not distributed after the mixer. As is clear from the CO ₂ temperature before the mixer inflow (CO ₂ back pressure valve outlet temperature T-5), the CO ₂ heater is used in the section where CO ₂ is consumed for pressure increase and does not flow after the mixer. It can be seen that the increase in the temperature of CO ₂ that should be heated at is suppressed and the temperature is lowered. At that time, since a high-viscosity fluid in which CO ₂ is not dissolved flows, the pressure loss increases, and the differential pressure data for measuring the viscosity of the paint after mixing increases. Further, when CO ₂ flows, the viscosity decreases, so the differential pressure also decreases.

On the other hand, FIG. 6 shows operation data of the carbon dioxide coating apparatus according to the present invention. By providing a back pressure valve in the CO ₂ line before mixing, the CO ₂ pressure P- 1 before mixing is higher than the mixing section pressure P- 4 and is controlled constantly. It can be seen that the CO ₂ temperature T-5 also shows a constant temperature and is stably supplied continuously. As a result, the pressure difference data indicating the viscosity of the paint after mixing does not change as much as that found in the existing method. Therefore, it can be seen that the properties of the fluid after mixing are stabilized. According to this example, the process pressure was not changed, and a very stable high-pressure process operation was realized.

CO ₂ mixture to high viscosity organic fluid containing molten resin, to spray-atomization techniques, illustrates an embodiment of the present invention. FIG. 7 shows an outline of the apparatus used in this example. As shown in the figure, a primary pressure control valve PCV-2 was installed in the high-pressure CO ₂ line. The volume of PCV-2 to mixer MX-1 was minimized. Specifically, high-pressure carbon dioxide has a low viscosity and is considered not to cause a problem of pressure loss. An orifice was provided downstream of the mixer, and the differential pressure across the front and back was measured, and it was possible to grasp on-line the viscosity lowering behavior caused by mixing CO ₂ with the molten resin.

  Moreover, in order to control the pressure of the fluid after mixing to be constant, a primary pressure regulating valve PCV-3 can be provided. Although this is not essential, the high-viscosity organic fluid containing the molten resin is higher in viscosity than the high-viscosity organic fluid containing the above-mentioned paint, so that the pressure fluctuation of the mixed fluid is minimized. It contributes to that. Although not shown, it is preferable to add a configuration capable of grasping the mass flow rate of the high-viscosity organic fluid containing the molten resin and the high-pressure carbon dioxide.

  The means for grasping the flow rate is not limited, and a Coriolis mass flow meter, a thermal flow meter, a differential pressure meter flow meter, an area flow meter, or the like was used. In addition, a high-pressure micromixer using a micro-channel was used as a mixer, and a stable and rapid mixing of a high-viscosity organic fluid containing a molten resin and high-pressure carbon dioxide was performed. Specifically, as the high-pressure micromixer, a multistage divided-type high-pressure micromixer was used. According to this example, the process pressure was not changed, and a very stable high-pressure process operation was realized.

  As described above in detail, the present invention relates to a processing method and apparatus for a high-viscosity organic fluid by continuous mixing of high-pressure carbon dioxide. According to the present invention, a high-viscosity organic fluid and high-pressure carbon dioxide are mixed. When mixing two fluids that have a difference in viscosity and a difference in flow rate, even if pressure fluctuations in the process occur, a pressure section is provided in the carbon dioxide supply line with a slow pressure increase rate, so that the Carbon dioxide can be supplied. Therefore, process pressure fluctuations can be minimized and process stabilization is achieved. In the processing method of the high-viscosity organic fluid containing paint or molten resin, intermittent supply of high-pressure carbon dioxide can be suppressed and the supply flow rate can be stabilized. New high-viscosity organic fluid processing that can replace the existing high-viscosity organic fluid processing technology that uses a large amount of organic solvent and can dramatically reduce the use of organic solvent Technology can be provided. It is possible to provide new technologies and new products related to a new processing method and apparatus for a high-viscosity organic fluid that is low in environmental load and has low organic solvent emissions and is continuously mixed with high-pressure carbon dioxide.

Claims (13)

And high-pressure carbon dioxide, a continuous mixing device for mixing continuously at high pressure processes and high-viscosity organic fluid in the paint or molten resin at a high viscosity than unrealized high-pressure carbon dioxide,
A high-viscosity organic fluid supply line for continuously supplying the high-viscosity organic fluid from a high-viscosity organic fluid source ;
A high-pressure carbon dioxide supply line that continuously supplies the high-pressure carbon dioxide from a high-pressure carbon dioxide source ;
A high-pressure mixing section for mixing the high-viscosity organic fluid and the high-pressure carbon dioxide;
A primary pressure control valve (PCV-2) for high-pressure carbon dioxide provided in the high-pressure carbon dioxide supply line in the vicinity of the high-pressure mixing unit;
A high-pressure carbon dioxide pump provided in the carbon dioxide supply line;
Comprising
The continuous mixing apparatus, wherein the set pressure of the primary pressure control valve is 1 to 5 MPa higher than the pressure in the high pressure mixing section. The continuous mixing apparatus according to claim 1, further comprising a mechanism for providing a pressure loss, which is provided downstream of the primary pressure control valve. The continuous mixing apparatus according to claim 2, wherein the mechanism that imparts the pressure loss is a metering needle valve or a capillary tube. Any one of Claims 1-3 further equipped with the secondary pressure control valve (PCV-4) for the high-viscosity organic fluid provided in the said high-viscosity organic-fluid supply line in the vicinity of the said mixing part. The continuous mixing apparatus of Claim 1. The continuous mixing apparatus according to claim 4, further comprising a relief valve provided upstream of the secondary pressure regulating valve (PCV-4) for the high viscosity organic fluid. 6. The apparatus according to claim 1, further comprising a primary pressure regulating valve (PCV-3) that is provided downstream of the high-pressure mixing unit and controls the pressure of the fluid after mixing to be constant. Continuous mixing equipment. The continuous mixing apparatus according to any one of claims 1 to 6, wherein the high-pressure mixing unit is a high-pressure micromixer using a microchannel. The continuous mixing apparatus according to claim 7, wherein the high-pressure micromixer is a multistage division type high-pressure micromixer, a center collision micromixer, a T-shaped micromixer, or a swirl mixer. Using a continuous mixing device according to any one of claims 1 to 8, the high-pressure and high-pressure carbon dioxide, the high-viscosity organic fluid with a paint or molten resin at a high viscosity than unrealized high-pressure carbon dioxide, the A method of continuous mixing in a process,
Supply high viscosity organic fluid from high viscosity organic fluid source to high viscosity organic fluid supply line,
High-pressure carbon dioxide is supplied from a high-pressure carbon dioxide source to the high-pressure carbon dioxide supply line at a pressure lower than the set pressure P1, which is the maximum discharge pressure of the high-pressure carbon dioxide pump. Is controlled to the set pressure P2 of the primary pressure control valve (PCV-2),
In the high-pressure mixing section, the high-viscosity organic fluid and high-pressure carbon dioxide are mixed,
The set pressure P2 is set to be 1 to 5 MPa higher than the pressure in the mixing section, and is a continuous mixing method that stabilizes the supply flow rate of high-pressure carbon dioxide and suppresses fluctuations in process pressure. The continuous mixing apparatus according to claim 4 or 5, wherein the pressure in the high-pressure mixing unit is controlled to a set pressure P4 of a secondary pressure regulating valve (PCV-4) for high viscosity organic fluid. The continuous mixing method according to 9. When the supply flow rate of high-pressure carbon dioxide is low, a pressure loss is applied downstream of the primary pressure control valve (PCV-2) for high-pressure carbon dioxide, and the primary pressure control valve (PCV for high-pressure carbon dioxide). The continuous mixing method according to claim 9 or 10, wherein the controllability of -2) is improved. Using the continuous mixing device according to claim 5, by Lilly off valve to avoid the high-pressure pump discharge pressure rise in the high-viscosity organic fluid supply line, continuous mixing method according to any of claims 9-11. The continuous mixing method according to claim 9, wherein the fluid after mixing is discharged from a spray nozzle, and the high-viscosity organic fluid is continuously sprayed, continuously formed, or continuously atomized from a high-pressure environment.

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