JP4160430B2 - Impregnation treatment method and impregnation treatment apparatus for impregnation in supercritical carbon dioxide - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an impregnation treatment method in which a substrate is impregnated with an impregnation substance in supercritical carbon dioxide. In particular, after the substrate is put into the impregnation tank in the atmosphere, the impregnation tank is sealed, the air in the impregnation tank is evacuated and then carbon dioxide is introduced, and impregnated in supercritical carbon dioxide. It is related with the impregnation processing method to make. Also that The present invention relates to an impregnation treatment apparatus used in the method.
[0002]
[Prior art]
Since dyeing of textile products uses a large amount of water, it is inevitable that a large amount of waste water including unfixed dyes and dyeing assistants is discharged after dyeing. Since this wastewater also causes water pollution, it is necessary to purify it, which is a great burden for companies that perform dyeing. On the other hand, a method of dyeing in supercritical carbon dioxide has recently been proposed as a dyeing method that does not discharge wastewater. In addition, not only textile products but also a method of impregnating various base materials with an impregnating substance in supercritical carbon dioxide has been proposed. At this time, carbon dioxide to be used can be recovered and reused.
[0003]
Regarding the method of collecting and reusing carbon dioxide when dyeing in supercritical carbon dioxide, it is described in JP 2000-500192 A (Patent Document 1) and JP 2002-517619 A (Patent Document 2). Has been. In these patent publications, the carbon dioxide fluid dyed in the supercritical fluid, and after the dyeing is completed, is supplied from the dyeing tank to the separation tank through the pressure reducing valve, where it is separated into residual substances and carbon dioxide gas. Is done. The separated carbon dioxide gas is liquefied by a condenser, heated and pressurized to a supercritical state, and supplied again to the dyeing tank. At this time, the liquefied carbon dioxide gas may be temporarily stored in the tank after liquefaction.
[0004]
In order to improve the solubility and dyeability of the dye, a method of dyeing in supercritical carbon dioxide containing a cosolvent has been proposed. In this way, when a co-solvent is used, methods for recovering and reusing carbon dioxide are described in JP-A No. 2002-129464 (Patent Document 3) and JP-A No. 2002-371484 (Patent Document 4). Yes. In these Patent Documents 3 and 4, the same impregnation and recovery steps as those described in Patent Documents 1 and 2 are employed.
[0005]
[Patent Document 1]
Japanese translation of PCT publication 2000-500192 (pages 11 to 13, FIG. 1)
[Patent Document 2]
JP-T-2002-517619 (pages 26-34, FIG. 1)
[Patent Document 3]
Japanese Patent Laid-Open No. 2002-129464 (pages 2 and 3, FIG. 1)
[Patent Document 4]
Japanese Patent Laid-Open No. 2002-37183 (pages 4-6, FIG. 1)
[0006]
[Problems to be solved by the invention]
Each of the above patent publications describes a basic technique for collecting and reusing carbon dioxide. On the other hand, in industrial production, it is necessary to impregnate a large amount of substrate by performing an impregnation operation in a large amount of supercritical carbon dioxide using a large-scale apparatus. It is preferable that a large amount of carbon dioxide recovered after the impregnation treatment is once stored in a storage tank. However, in the recovery methods described in the above publications, it is inevitable that air is mixed into the recovered carbon dioxide, and when a large amount of carbon dioxide is repeatedly recovered and reused, a storage tank Air tends to accumulate inside. When the accumulated amount of air increases, there is a possibility that troubles may occur due to air mixed in carbon dioxide in a pressurizing process at the time of reuse.
[0007]
Further, if the substrate to be impregnated contains moisture, the impregnation property may be affected. For example, if a dyeing operation is performed, the dyeing concentration may fluctuate due to the influence of moisture, and there is a problem that the dyeability deteriorates depending on the type of base material and the type of dye.
[0008]
The present invention has been made to solve such problems, and provides an impregnation treatment method in which air is less mixed into recovered carbon dioxide. Furthermore, the present invention also provides an impregnation method that can prevent the adverse effects of moisture present during the impregnation treatment.
[0009]
[Means for Solving the Problems]
In the impregnation treatment method for impregnating a base material with an impregnation substance in supercritical carbon dioxide, the above-mentioned problem is that after the base material is put into the impregnation treatment tank in the atmosphere, the impregnation treatment tank is sealed, This is solved by providing an impregnation method characterized in that air is evacuated and carbon dioxide is introduced and impregnated in supercritical carbon dioxide. By doing so, it is possible to prevent air from being mixed into the recovered carbon dioxide.
[0010]
At this time, it is preferable that the impregnation treatment tank is heated when evacuating under reduced pressure. Also, after reaching a predetermined degree of vacuum, it is preferable to heat the base material while continuing the vacuum exhausting operation, and then introduce carbon dioxide, and put the base material that has been previously dried into the impregnation treatment tank. Is also suitable. Both help to prevent the adverse effects of moisture present during the impregnation process. At this time, it is also preferable to impregnate in supercritical carbon dioxide containing a co-solvent. By including a co-solvent, the solubility and dyeability of the dye can be improved.
[0011]
In addition, after impregnation in supercritical carbon dioxide in the impregnation treatment tank, the fluid after the impregnation treatment is introduced from the impregnation treatment tank into the gas separation device, and the impregnation material is removed by the gas separation device, and the obtained carbon dioxide It is preferable to recover the gas and reuse it. Thus, when recovering and using carbon dioxide, the actual benefit of the present invention is great. In a preferred embodiment, the substrate is a textile product, and the impregnating material is a dye.
[0012]
The object of the present invention is also solved by providing a product impregnated by the above impregnation method. Further, in the impregnation processing apparatus for impregnating the base material with the impregnated substance in supercritical carbon dioxide, it has means for heating the impregnation treatment tank and means for evacuating the air in the impregnation treatment tank. This is also achieved by providing a characteristic impregnation apparatus.
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the impregnation treatment method of the present invention will be described with reference to the drawings. FIG. 1 is a view showing an impregnation processing apparatus showing an example of an embodiment of the present invention.
[0014]
In the present invention, the base material is impregnated with the impregnating substance in supercritical carbon dioxide in the impregnation treatment tank 10. The impregnation treatment tank 10 is composed of a pressure vessel, and usually requires a pressure resistance of 10 MPa or more, preferably 15 MPa or more, more preferably 20 MPa or more. The internal volume of the impregnation treatment tank 10 is preferably 100 liters or more, more preferably 200 liters or more, and even more preferably 300 liters or more in consideration of industrial production. The impregnation treatment tank 10 shown in FIG. 1 has an internal volume of 450 liters and is made of thick stainless steel.
[0015]
The impregnation treatment tank 10 has a door 11 that can be opened and closed. The door 11 is opened, and the base material is put into the impregnation treatment tank 10 in the atmosphere. A rotating basket 12 is provided inside the impregnation treatment tank 10. By introducing the substrate to be treated into this and impregnating it while rotating, a uniform impregnation operation without unevenness can be performed.
[0016]
The substrate impregnated by the impregnation treatment method of the present invention is not particularly limited, but is preferably a substrate mainly composed of a polymer compound. The polymer compound referred to here may be either a synthetic polymer compound or a natural polymer compound. Examples of such products include textile products, leather, wood, films, and plastic molded products. Among these, textile products, leather, wood, films, and the like are preferable because they can be efficiently impregnated because of their large surface areas.
[0017]
Of these, textile products are the most useful. Examples of the textile product include yarn, fabric, paper, and the like. As the fabric, a woven fabric, a knitted fabric, a non-woven fabric, or the like can be used, and it is also preferable to impregnate the sewed fabric. For example, when impregnating a volatile fragrance component or the like, it is not always preferable to perform sewing processing in a state where the fragrance component may volatilize after the impregnation treatment. It is preferred to do so.
[0018]
Textile materials include cotton, rayon, nylon (6, 66, etc.), polyester, acrylic, polypropylene, silk, wool, acetate (including triacetate), polyethylene, aramid (meta and para), polyurethane, vinylon, Examples thereof include polyvinyl chloride and polyvinylidene chloride. It is also preferable to impregnate the paper. This is because paper is usually difficult to maintain its form in water, but can retain its form in supercritical carbon dioxide. The type of paper is not particularly limited, but is usually entangled with cellulose short fibers such as pulp.
[0019]
It is also preferable to impregnate leather or wood. This is because these materials often deform or impair the texture when impregnated in water. In addition, impregnation into a film or plastic molded product is also possible. Since the film has a small thickness and a relatively large surface area, it is easy to impregnate and is a preferable substrate. Further, for example, it is possible to impregnate only the surface of a plastic molded article with an antibacterial agent, which is effective for antibacterialization of children's toys. The plastic molded product here means a molded product having a larger thickness and diameter than films and fibers, and includes not only a three-dimensional three-dimensional molded product but also a thick sheet and a rod-shaped body having a large diameter. .
[0020]
Moreover, the impregnation substance used by this invention will not be specifically limited if it melt | dissolves in a supercritical carbon dioxide and can be made to impregnate in a base material. Suitable examples include dyes. The dye used is not particularly limited, and either a synthetic dye or a natural dye can be used.
[0021]
The synthetic dye is not particularly limited. Examples include disperse dyes, oil-soluble dyes, reactive dyes, reactive disperse dyes, direct dyes, acid dyes, basic dyes, selenium dyes, sulfur dyes, indigo dyes, and metal-containing dyes. Of these, disperse dyes, oil-soluble dyes, direct dyes, and reactive disperse dyes are preferably used because of their good dyeability in supercritical fluids. Of these, disperse dyes, oil-soluble dyes and direct dyes are more preferably used, and disperse dyes and oil-soluble dyes are more preferably used.
[0022]
Natural dyes composed of animal and plant extract components can also be used. It may be dyed in a supercritical fluid using already extracted dye components such as plant dyes and food colors, or may be extracted from animals and plants in a supercritical fluid and dyed as it is. The animal and plant from which the dye component is extracted is not particularly limited as long as it contains a component capable of dyeing an object to be dyed, particularly a fiber. In general, plants are preferably used as so-called plant dyeings. Although animals and plants can be subjected to an extraction operation as they are, dried ones are preferably used because it is easy to ensure preservation and quality uniformity. In this case, although a tank for extraction with a supercritical fluid can be prepared separately, it is preferable to perform extraction and impregnation simultaneously in the impregnation treatment tank.
[0023]
In addition to dyes, materials that can be suitably used as impregnating materials include materials (functional processing agents) that can impart various functions to a substrate. Examples of such impregnating substances include aromatic substances, medicinal substances, antibacterial agents, insecticides, fungicides, deodorants, deodorants, softeners, curing agents, anti-wrinkle agents, antishrink agents, and pilling. Inhibitors, waterproofing agents, water repellents, sweat absorbing agents, fluorescent whitening agents, darkening agents, antifouling agents, antistatic agents, fireproofing agents (fireproofing agents, flame retardants, flameproofing agents, etc.), antioxidants, Examples thereof include an anti-aging agent, an ultraviolet absorber, a light-resistant stabilizer, a shape memory processing agent and an electromagnetic wave shielding processing agent. Some of these are volatilized, difficult to dissolve or disperse in water, easily eluted into water after impregnation, and easily deteriorated at high temperatures. It is often preferable to impregnate in carbon. Among them, preferred are aromatic substances, medicinal substances, antibacterial agents, insect repellents and fungicides. This is because many of these materials are particularly likely to volatilize, elute in water, or deteriorate at high temperatures. When the components extracted from animals and plants contain aromatic substances, medicinal substances, antibacterial agents, insect repellents and fungicides, it is also preferable to impregnate them with the substrate simultaneously with the extraction. Moreover, the dye component can be impregnated simultaneously with these substances.
[0024]
After the base material is put into the impregnation treatment tank 10 and an impregnation substance is introduced as necessary, the door 11 is closed to seal the impregnation treatment tank 10. Subsequently, the valve 13 is opened, and the air in the impregnation treatment tank 10 is exhausted under reduced pressure by the vacuum pump 14. A means for exhausting the air in the impregnation tank 10 under reduced pressure is not particularly limited, but a vacuum pump 14 is usually used. The type of the vacuum pump 14 is not particularly limited, and is appropriately selected in consideration of the required degree of decompression, exhaust speed, ease of maintenance, price, and the like. In the example of FIG. 1, a water ring vacuum pump is used. The water-sealed vacuum pump does not necessarily have a high degree of pressure reduction, but the pressure reduction performance is not deteriorated by the water flowing from the impregnation treatment tank 10 and maintenance is easy, so that it is preferably used. Depressurization is started from atmospheric pressure (about 0.1 MPa), preferably 0.03 MPa or less, more preferably 0.02 MPa or less, and even more preferably 0.01 MPa or less.
[0025]
It is preferable that the impregnation treatment tank 10 is heated when evacuating under reduced pressure. When the impregnation treatment operation is repeated, the base material is charged after discharging the carbon dioxide fluid after the previous impregnation treatment. In this case, latent heat is taken away due to the vaporization of carbon dioxide, and the impregnation treatment tank 10 may be cooled to cause dew condensation on the surface. However, by heating the impregnation treatment tank 10, such moisture is impregnated. It is possible to prevent contamination during processing. Moreover, the water | moisture content adhering to a base material and the water | moisture content contained in a base material can also be reduced. The heating of the impregnation treatment tank 10 may be continued from the previous impregnation treatment, or the heating may be started before and after the substrate loading operation.
[0026]
It is more preferable to heat the base material while continuing the decompression / exhaustion operation after evacuating the vacuum and reaching a predetermined degree of decompression. By doing so, it is possible to sufficiently reduce the moisture contained in the substrate, and to prevent the adverse effect of moisture present during the impregnation treatment. Since supercritical carbon dioxide is essentially a hydrophobic fluid, moisture contained in the substrate is difficult to elute into the supercritical fluid. Therefore, moisture is likely to remain in the substrate even in supercritical carbon dioxide. Under such circumstances, it is difficult to impregnate the substrate with an impregnating substance, particularly a hydrophobic impregnating substance. Taking dyeing operations as an example, when dyeing fibers with high water absorption, such as cellulose and nylon, with hydrophobic dyes such as disperse dyes, they are easily affected by the water content and dyeability tends to decrease. .
[0027]
Therefore, when a hydrophilic material such as cotton, silk, wool, vinylon, nylon, rayon, paper, leather, wood, or the like is used as the substrate, it is preferable to perform the above-described reduced pressure heating operation. In particular, when the substrate is a textile product such as cotton, silk, wool, vinylon, nylon, rayon, paper, etc., it is preferable because moisture can be removed in a relatively short time. Moreover, when using a hydrophobic thing as an impregnation substance, the actual profit which performs the said pressure reduction heating operation is large. Hydrophobic impregnated substances are originally easy to dissolve in supercritical carbon dioxide, and it is preferable to impregnate in supercritical carbon dioxide, but the impregnation property deteriorates due to the influence of moisture contained in the substrate. Because it is easy to do. Therefore, for example, in the case of a dye, when the disperse dye and the oil-soluble dye are impregnated, the actual benefit of performing the reduced pressure heating operation is great.
[0028]
The heating temperature when heating the substrate while evacuating under reduced pressure is not particularly limited, but is preferably 30 to 250 ° C. In the case of 30 ° C. or lower, the amount of water decrease in the substrate may be insufficient, more preferably 50 ° C. or higher, and even more preferably 70 ° C. or higher. On the other hand, if it exceeds 250 ° C, the substrate may be deteriorated, more preferably 200 ° C or less, and further preferably 150 ° C or less. Here, the heating temperature refers to the temperature of the space in the impregnation treatment tank 10. In the example of FIG. 1, the temperature is indicated by a thermometer 15 made of a thermocouple arranged so as to protrude from the inner wall of the impregnation treatment tank 10 into the inner space. The means for heating the impregnation treatment tank 10 is not particularly limited. Techniques such as an electric heater, steam heating, and heating medium heating can be employed, and a plurality of heating techniques may be used in combination. In the example of FIG. 1, the periphery of the impregnation treatment tank 10 is covered with a jacket 16, and oil of a heat medium is circulated in the jacket 16 to heat the impregnation treatment tank 10.
[0029]
The heating method of the heating medium is not particularly limited, and any heating method can be adopted. In the example of FIG. 1, a heating medium supply device 20 that has a heating means using a steam heater and a heating means using an electric heater and further has a cooler composed of a heat exchanger is used. Since control of the temperature of the impregnation treatment tank 10 is necessary not only during heating of the base material before the impregnation treatment but also during the impregnation treatment operation, it is preferable to enable fine temperature control with such a configuration. In the example of FIG. 1, the heat medium is used in common with the heater 58 for heating the carbon dioxide fluid supplied to the impregnation treatment tank 10 by operating the valve 21 and the valve 22. By doing so, the temperature of the carbon dioxide fluid introduced into the impregnation treatment tank 10 and the temperature of the impregnation treatment tank 10 can be maintained at the same level, and stable temperature management is facilitated during the impregnation treatment.
[0030]
In the impregnation treatment tank 10, after evacuating and reaching a predetermined degree of decompression, the time for heating the substrate while continuing the evacuation operation is appropriately adjusted according to the material, form or moisture content of the substrate. The time for heating the substrate is preferably 1 to 60 minutes. When the heating time is less than 1 minute, the moisture in the substrate may not be removed sufficiently, more preferably 2 minutes or more, and even more preferably 5 minutes or more. On the other hand, if the heating time exceeds 60 minutes, the cycle time of the impregnation treatment becomes too long, and the utilization efficiency of the impregnation treatment equipment may be lowered, and more preferably 30 minutes or less.
[0031]
Further, after evacuation under reduced pressure, the depressurization operation may be continued without heating. In this case, it is possible to prevent the base material and the impregnated material from being deteriorated by heat, although the speed at which the water content is reduced is lower than in the case of heating. Therefore, this method is suitably employed when the substrate or impregnated material is easily deteriorated by heating. At this time, it is suitable that the time for continuing the decompression operation is 10 to 60 minutes.
[0032]
As described above, the air in the impregnation tank 10 is evacuated and heated as necessary. This operation may be repeated not only once but also twice or more. For example, after exhausting under reduced pressure, the valve 59 may be opened slightly to introduce a small amount of carbon dioxide, and then exhausted under reduced pressure again. By carrying out like this, the quantity of the air which remains in the impregnation processing tank 10 can be reduced further, and the quantity of the water | moisture content contained in a base material can also be reduced. In particular, when the operation of heating the impregnation treatment tank 10 is performed, the moisture in the base material can be more effectively reduced by repeating the operation.
[0033]
Instead of heating the base material in the impregnation treatment tank 10, it is also preferable to put a base material that has been dried in advance into the impregnation treatment tank 10. Since the pre-dried base material is put into the impregnation treatment tank 10, it is possible to shorten the time for removing moisture from the base material in the impregnation treatment tank 10, and to shorten the cycle time of the entire impregnation treatment. Can do. This is especially effective when the working environment is humid, such as in the rainy season, when the moisture content of the substrate is high, or when the substrate is difficult to dry, such as a thick molded product. . It is also preferable to heat the substrate in the impregnation treatment tank 10 after the substrate previously dried in this manner is put into the impregnation treatment tank 10 and the air in the impregnation treatment tank 10 is exhausted under reduced pressure. This is because the moisture content can be sufficiently reduced while shortening the cycle time of the impregnation treatment operation.
[0034]
When the substrate is previously dried, a separate dryer is used, but the type of the dryer is not particularly limited. You may use the hot air dryer heated under a normal pressure, and you may use the vacuum dryer dried by pressure reduction. It is preferable to heat at the time of drying, and the drying temperature is preferably 50 to 250 ° C. In the case of 50 ° C. or lower, there is a possibility that the amount of water decrease in the substrate becomes insufficient, and more preferably 70 ° C. or higher. On the other hand, if it exceeds 250 ° C, the substrate may be deteriorated, more preferably 200 ° C or less, and further preferably 150 ° C or less. Here, the heating temperature refers to the temperature of the space in the dryer. As the decompression conditions for drying under reduced pressure, the same conditions as the decompression conditions of the impregnation treatment tank 10 are preferably employed. Moreover, it is also preferable to heat at the same time when drying under reduced pressure, and the above drying temperature is suitably employed as the temperature in this case.
[0035]
The drying time is not particularly limited, but is preferably 1 minute or longer. When the heating time is less than 1 minute, there is a risk that the removal of moisture in the substrate may be insufficient, more preferably 5 minutes or more, and even more preferably 20 minutes or more. Unlike the case of heating in the impregnation treatment tank 10, it is not necessary to consider the cycle time of the impregnation treatment, so the drying time may be longer. However, depending on the heating temperature, if the heating time is too long, the substrate may be deteriorated. Therefore, the drying time is usually preferably 1 day or less.
[0036]
The air in the impregnation tank is evacuated and preferably the substrate is heated under reduced pressure before carbon dioxide is introduced. In the example of FIG. 1, the valve 59 is opened to introduce carbon dioxide, and the impregnation treatment tank 10 is filled with supercritical carbon dioxide to start the impregnation treatment. The critical point of carbon dioxide is a temperature of 31.3 ° C. and a pressure of 7.4 MPa, and it is relatively easy to make a supercritical fluid exceeding this temperature.
[0037]
When supercritical carbon dioxide contains a cosolvent, the solubility of an impregnating substance such as a dye in supercritical carbon dioxide is often improved. Moreover, even if the base material such as the fiber product is hydrophilic, it becomes easy to efficiently impregnate the impregnating substance therein. Further, after impregnating substances such as dyes are dissolved or dispersed in a co-solvent, they can be introduced into supercritical carbon dioxide.
[0038]
As the co-solvent used in the present invention, a polar organic solvent is preferable. Polar organic solvents include alcohols, ketones, cyclic ethers, amides and sulfoxides. Alcohols include methanol, ethanol, propanol, butanol, pentanol, hexanol, heptanol, octanol, undecanol, glycol (ethylene glycol, propylene glycol, butylene glycol), glycol derivatives, ethyl glycols, butyl glycols, glycerin, pentaerythritol, etc. As the ketone, acetone, methyl ethyl ketone, methyl isopropyl ketone, methyl isobutyl ketone, and dibutyl ketone are exemplified. Examples of suitable cyclic ethers include tetrahydrofuran (THF), examples of amides include dimethylformamide (DMF), and examples of sulfoxides include dimethyl sulfoxide (DMSO).
[0039]
In particular, in view of recovery and reuse, it is preferable that the boiling point is relatively low, for example, the boiling point is 150 ° C. or lower, and more preferably 100 ° C. or lower. On the other hand, when the boiling point is too low, the co-solvent is likely to be mixed into the recovered carbon dioxide gas, so the boiling point is preferably 40 ° C. or higher, and more preferably 60 ° C. or higher. Examples include methanol, ethanol, n-propanol, isopropanol, acetone, methyl ethyl ketone, and THF. Furthermore, ethanol, n-propanol, isopropanol, and acetone are preferable when considering the safety of workers, and ethanol is most preferable. These cosolvents may be used alone or in combination of two or more.
[0040]
The amount of co-solvent added to supercritical carbon dioxide is preferably 0.01 to 10%. When the content is less than 0.01%, the effect of adding the co-solvent decreases, and the extraction operation and the impregnation operation of the hydrophilic active ingredient may not be performed efficiently. More preferably, it is 0.1% or more, More preferably, it is 0.2% or more. On the other hand, when the amount of the co-solvent exceeds 10%, not only the impregnation property is lowered, but also the solvent remains in the fiber after the impregnation operation, and a post-treatment for removing the solvent is separately required. More preferably, it is 5% or less, and more preferably 2% or less. "%" Here is the ratio of the volume under normal pressure of the co-solvent introduced into the container filled with supercritical fluid to the container volume multiplied by 100,
[(Volume of added co-solvent) / (Volume of supercritical fluid)] × 100
It is shown by.
[0041]
The impregnation treatment condition is not particularly limited as long as the inside of the impregnation treatment tank 10 is in a supercritical state. A suitable pressure is 7 to 35 MPa. When it is less than 7 MPa, impregnation is often difficult, and more preferably 10 MPa or more. On the other hand, if it exceeds 35 MPa, the apparatus becomes large and the energy required for the impregnation treatment also increases, more preferably 30 MPa, and even more preferably 25 MPa or less. A suitable temperature for impregnation in supercritical carbon dioxide is 30 to 250 ° C. When the temperature is lower than 30 ° C., the impregnation treatment is not smooth and the operation time may be long. More preferably, it is 50 degreeC or more, More preferably, it is 70 degreeC or more. On the other hand, if the temperature exceeds 250 ° C., the base material and the impregnated material may be deteriorated, and the required energy also increases. More preferably, it is 150 ° C. or lower. Further, when impregnating with an impregnating substance that is particularly vulnerable to heating, or when impregnating a substrate that is particularly susceptible to heating, it may be preferable to set the temperature to 100 ° C. or lower.
[0042]
The time required for the impregnation treatment is usually 5 to 200 minutes. If it exceeds 200 minutes, the working efficiency may decrease, and the active ingredient may deteriorate depending on the processing temperature. More preferably, it is 120 minutes or less. On the other hand, in a time of less than 5 minutes, there are many cases where the impregnation is not sufficient, and impregnation unevenness is likely to occur. More preferably, it is 10 minutes or more.
[0043]
The impregnating substance may be introduced into the impregnation treatment tank 10 in advance, or may be introduced later into the impregnation treatment tank 10 filled with supercritical carbon dioxide. When the impregnated substance is extracted from the plants and animals in the impregnation treatment tank 10, a basket or the like containing the plants and animals can be disposed. Separately, a tank for dissolving the impregnating substance in supercritical carbon dioxide may be provided, and the solution may be introduced into the impregnation processing tank 10 from there through a pipe. When a co-solvent is used, it can be introduced from the co-solvent tank 23 into the impregnation treatment tank 10 via the co-solvent supply pump 24 and the valve 25.
[0044]
When the impregnation process is completed, the decompression valve 30 is opened, and the fluid after the impregnation process is introduced from the impregnation process tank 10 into the gas separation tank 31. In the gas separation tank 31, the carbon dioxide gas and the impregnated material are separated. The form of the gas separation device does not need to be in the form of a tank as shown in FIG. 1, but in general, it is preferably in the form of a tank. The component to be separated is an impregnating substance that is a liquid component or a solid component, a co-solvent, or the like. The liquid removed from the carbon dioxide gas in the gas separation tank 31 is removed via a valve 32 provided at the bottom of the gas separation tank 31. When the liquid containing the cosolvent is discharged from the valve 32, it is preferable to distill the liquid to recover the cosolvent and reuse it. The inside of the gas separation tank 31 is normally set to a temperature of about −10 to 150 ° C. and a pressure of about 0.1 to 5 MPa. Here, the pressure of 0.1 MPa means that the pressure is the same as the atmospheric pressure, and the differential pressure when compared with the surrounding environment is zero. At this pressure, carbon dioxide exists as a gas and is separated from solid and liquid components.
[0045]
The carbon dioxide gas led out from the gas separation tank 31 is compressed by the compressor 34 via the valve 33, introduced into the storage tank 40 via the valve 35, and stored as liquefied carbon dioxide. The temperature of the stored liquefied carbon dioxide is not particularly limited, but is usually about 0 to 40 ° C. Moreover, although the pressure of the stored liquefied carbon dioxide is not particularly limited, it is usually 3 to 10 MPa.
[0046]
After introducing the base material into the impregnation treatment tank 10 in the atmosphere, carbon dioxide is introduced without evacuating the air in the impregnation treatment tank 10 and impregnating in supercritical carbon dioxide. Air will be mixed in the carbon dioxide gas. The mixed air is present as gas in the upper space 41 in the storage tank 40. Therefore, when the amount of air mixed in increases, the storable amount of liquefied carbon dioxide decreases. Further, when the liquefied carbon dioxide is extracted from the bottom 42 of the storage tank 40 and reused, air may be mixed into the extracted liquefied carbon dioxide. When extracting, since the pressure inside the storage tank 40 decreases, it may boil and foam, and in such a case, even if liquefied carbon dioxide remains in the storage tank 40, The air in the upper space 41 may be mixed. Such a boiling phenomenon is actually observed from the level gauge 43 of the storage tank 40.
[0047]
The capacity of the storage tank 40 is appropriately set according to the capacity of the impregnation tank 10 and the like, but in order to secure a capacity capable of stably supplying carbon dioxide, it is preferably 200 liters or more, and 500 liters. More preferably. In the example of FIG. In order to solve the problem due to air mixing as described above, the capacity of the storage tank 40 may be increased. However, since the storage tank 40 is a pressure vessel, when the capacity is increased, the equipment cost is increased. Will rise significantly.
[0048]
The amount of air mixed in the gas in the upper space 41 of the storage tank 40 can be quantified by sampling the gas and using a gas chromatograph. Then, according to the analysis result, the carbon dioxide gas mixed with air is discharged by opening the valve 44 provided in the pipe drawn from the upper part of the tank. However, when the amount of air mixed in is large, the frequency of quantitative analysis and valve opening increases, the work load increases, and carbon dioxide is also released at the same time. According to the impregnation treatment method of the present invention, the amount of air mixed in can be greatly reduced, so that such a problem is improved.
[0049]
The liquefied carbon dioxide extracted from the bottom 42 of the storage tank 40 is sent to subsequent processes via the valve 54 and the valve 55. A pipe connected to the receiving tank 50 is branched between the valve 54 and the valve 55. In the receiving tank 50, purchased unused liquefied carbon dioxide is stored, and from this, liquefied carbon dioxide is supplied through the valve 51, the transport pump 52, and the valve 53. By operating the transport pump 52 and switching the valves 53, 54, and 55, unused liquefied carbon dioxide can be appropriately added to the carbon dioxide to be recovered and reused. The liquefied carbon dioxide led out from the storage tank 40 and passed through the valve 54 and the valve 55 is pressurized by the pressure pump 56, heated by the heater 58 through the valve 57, and supplied to the impregnation treatment tank 10 through the valve 59. Supplied.
[0050]
When air is mixed in liquefied carbon dioxide, the pressurization capacity may be reduced when pressurization is performed by the pressurization pump 56. Therefore, it is important to prevent air contamination by the impregnation method of the present invention. As the pressurizing pump 56 to be used, a diaphragm pump and a plunger pump are exemplified, but a diaphragm pump is preferably used because there is no liquid leakage. However, it is particularly important to prevent air from being mixed into carbon dioxide because the performance of the diaphragm pump is likely to deteriorate due to air bubbles mixed inside.
[0051]
In this way, pressurized and heated carbon dioxide is supplied, the impregnation treatment tank 10 is filled with supercritical carbon dioxide having a desired condition, and the impregnation treatment is performed. In this way, carbon dioxide is recovered and reused. Taking a dyeing operation as an example, in the case of dyeing a textile product in supercritical carbon dioxide, compared to the case of dyeing with water as a medium, the waste water is not discharged, and thus this is an environmentally friendly process. In addition to this, it is also excellent in terms of energy in that it does not require energy to dry the dyed fiber product. Moreover, since the carbon dioxide of the medium can be recovered and reused in this way, it is a very significant process from the viewpoint of environmental protection.
[0052]
【Example】
Example 1
Dyeing was performed using the impregnation apparatus shown in FIG. First, 10 kg of nylon cloth was put into the rotating basket 12 in the impregnation tank 10. After the door 11 was closed, the valve 13 was opened, and the air in the impregnation treatment tank 10 was exhausted under reduced pressure by the vacuum pump 14. At this time, oil of a heat medium was circulated in the jacket 16. By evacuating for 10 minutes, the inside of the impregnation treatment tank 10 is decompressed from atmospheric pressure (0.1 MPa) to 60 mmHg (0.008 MPa). At that time, the thermometer 15 in the impregnation treatment tank 10 shows 100 ° C. It was. Subsequently, when kept under a reduced pressure condition of 60 mmHg for 20 minutes, the temperature indicated by the thermometer 15 increased to 120 ° C. during that time and became constant. After 20 minutes, the valve 13 was closed, and the rotary basket 12 was rotated, the valve 59 was opened, and the impregnation treatment tank 10 was filled with supercritical carbon dioxide.
[0053]
0.2 owf of the disperse dye was dissolved in 1% by volume of ethanol (4.5 liters) of the volume of the impregnation treatment tank 10 (450 liters) and charged into the cosolvent tank 23. The disperse dye used is “KAYASET Yellow AG” manufactured by Nippon Kayaku Co., Ltd. After filling the impregnation treatment tank 10 with supercritical carbon dioxide, the co-solvent supply pump 24 was operated, and the valve 25 was opened to supply the dye solution to the impregnation treatment tank 10. The dyeing process was performed for 30 minutes while continuing to rotate the rotating basket 12 at 120 ° C. and 19 MPa. After 30 minutes, the decompression valve 30 was opened, the fluid in the impregnation tank 10 was discharged, the door 11 was opened, and the dyed nylon cloth was taken out.
[0054]
The degree of coloring of the obtained nylon cloth was evaluated by total K / S. The total K / S is a total value of 16 K / S values at 16 wavelengths measured every 20 nm in the measurement range of 400 nm to 700 nm. The chromaticity meter AUCOLOR NF (2 fields, light source FL40SW manufactured by Kurashiki Boseki Co. ). As a result, the total K / S value was 113.
[0055]
The carbon dioxide decompressed by the decompression valve 30 was led to the gas separation tank 31 where it was separated from the cosolvent and undyed dye, compressed by the compressor 34 and stored in the storage tank 40 as liquefied carbon dioxide. The stored liquefied carbon dioxide was pressurized and heated by the pressure pump 56 and the heater 58, supplied to the impregnation treatment tank 10, and reused. Even if the dyeing operation was repeated under these conditions and the recovered carbon dioxide was reused, no reduction in the capacity of the pressurizing pump 56 was observed.
[0056]
Example 2
Dyeing was performed in the same manner as in Example 1 except that the operation of heating for 20 minutes under a reduced pressure condition of 60 mmHg was not performed. That is, by evacuating for 10 minutes, the pressure was reduced to 60 mmHg. When the thermometer 15 in the impregnation treatment tank 10 showed 100 ° C., the valve 59 was immediately opened, and the inside of the impregnation treatment tank 10 was supercritical carbon dioxide. Filled with. Subsequent operations were carried out in the same manner as in Example 1 to obtain a dyed nylon cloth. The obtained nylon cloth had a total K / S value of 92. The dyeing density was lower than that of the nylon cloth obtained in Example 1, and it was shown that the dyeability could be improved by removing moisture by heat treatment under reduced pressure.
[0057]
Comparative Example 1
The dyeing process was performed in the same manner as in Example 1 except that the operation of evacuating the air in the impregnation treatment tank 10 was not performed. That is, after the nylon cloth was put into the impregnation treatment tank 10 and the door 11 was closed, the valve 59 was immediately opened to fill the impregnation treatment tank 10 with supercritical carbon dioxide. Subsequent operations were carried out in the same manner as in Example 1 to obtain a dyed nylon cloth. The obtained nylon cloth had a total K / S value of 88. Compared to the nylon cloth obtained in Example 2, the dyeing density is further lowered, and it seems that more moisture remains in the nylon cloth.
[0058]
Under these conditions, the staining operation was repeated, and carbon dioxide was recovered and reused. However, when the number of times of repeated dyeing has reached about 20, a decrease in the capacity of the pressurizing pump 56 has been recognized. This is presumed to be because the air accumulated in the storage tank 40 was mixed into the pressure pump.
[0059]
【The invention's effect】
According to the impregnation treatment method of the present invention, it is possible to reduce the mixing of air into the recovered carbon dioxide. In particular, even when impregnating a large amount of substrate by repeatedly impregnating it in a large amount of supercritical carbon dioxide using a large-scale apparatus during industrial production, troubles in the process due to accumulation of air are caused. It becomes possible to prevent. Moreover, the impregnation processing method which can prevent the bad influence of the water | moisture content which exists at the time of an impregnation process can also be provided. In addition, it is possible to provide an environment-friendly impregnation treatment method in which the amount of discharge to the surrounding environment is reduced.
[Brief description of the drawings]
FIG. 1 is a view showing an impregnation processing apparatus showing an example of an embodiment of the present invention.
[Explanation of symbols]
10 Impregnation tank
11 Door
12 Rotating basket
14 Vacuum pump
15 Thermometer
16 jacket
20 Heating medium supply device
23 Co-solvent tank
24 Co-solvent supply pump
30 Pressure reducing valve
31 Gas separation tank
34 Compressor
40 storage tank
41 Upper space
50 receiving tank
52 Transfer pump
56 Pressure pump
58 Heater

Claims (9)

In the impregnation method of impregnating a base material with an impregnated substance in supercritical carbon dioxide, the base material is put into the impregnation tank in the atmosphere, then the impregnation tank is sealed, and the air in the impregnation tank is exhausted under reduced pressure. Then, carbon dioxide is introduced and impregnated in supercritical carbon dioxide. The impregnation method according to claim 1, wherein the impregnation treatment tank is heated when evacuating under reduced pressure. The impregnation method according to claim 1 or 2, wherein after the predetermined pressure reduction degree is reached, the base material is heated while continuing the vacuum exhaust operation, and then carbon dioxide is introduced. The impregnation method according to any one of claims 1 to 3, wherein a substrate that has been previously dried is put into an impregnation treatment tank. The impregnation method according to any one of claims 1 to 4, wherein the impregnation is performed in supercritical carbon dioxide containing a cosolvent. After impregnation in supercritical carbon dioxide in the impregnation treatment tank, the fluid after the impregnation treatment is introduced from the impregnation treatment tank into the gas separation device, the impregnation material is removed by the gas separation device, and the obtained carbon dioxide gas is used. The impregnation method according to any one of claims 1 to 5, which is recovered and reused. The impregnation method according to any one of claims 1 to 6, wherein the substrate is a textile product. The impregnation method according to claim 1, wherein the impregnating substance is a dye. An impregnation treatment apparatus for impregnating a base material with an impregnation substance in supercritical carbon dioxide has a means for heating the impregnation treatment tank and a means for evacuating the air in the impregnation treatment tank. Impregnation processing equipment.

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