JPS59199767A - Dye purification equipment - Google Patents

Abstract

PURPOSE:To provide a continuous purification equipment for dye solution useful for ink, etc., capable of removing the inorganic salts in said solution, equipped with three devices, namely, for its manufacture, its treatment constituted by chromatographic operation, and for detecting the inorganic salt concentration in the resultant solution. CONSTITUTION:A dye powder 22 is dissolved, in the preparation tank 24, in the pure water fed through a pipe 26 to prepare a dye solution. Subsequently, this solution is filtered to remove contaminated particles, etc., being fed to the feed tank 31 followed by feeding the solution through pipes 47 to the purification section 41 constituted by a plural of salt-reducing treatment units 42, where said solution is subjected to a chromatographic operation through the on-off valves 43 by feeding it to the filter units 44 consisting of columns 441 to eliminate the inorganic salts contaminated followed by detecting the dye and inorganic salt concentrations in the resultant two kinds of solutions respectively, then bringing the dye solution through the on-off valves 45 via pipes 55 to the storage tank 56, whereas the inorganic salt solution is discharged, through pipes 57, to the tank 58.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a dye purification device, and particularly to a dye purification device that continuously supplies purified dye suitable for preparing recording liquid (generally referred to as ink) suitable for inkjet recording, writing instruments, etc. Regarding.

[Prior Art] Conventionally, ink used in the inkjet recording method, in which recording is performed by ejecting ink in a recording head from an ejection orifice using vibrations caused by a piezo vibrator, has been made by mixing various dyes and pigments with water or other organic solvents. It is known to be dissolved or dispersed in a liquid medium consisting of: It is also known that similar inks are used in writing instruments such as felt pens and fountain pens.

An example of a general basic composition of such an ink is one in which the main components are a water-soluble dye, water as its solvent, and the king of glycols as an anti-drying agent.

Here, the water-soluble dye usually contains a large amount of inorganic salts such as sodium chloride and sodium sulfate. These inorganic salts are not only those produced as by-products during the dye synthesis reaction process, but also those that are actively added as salting-out agents, diluents, or leveling agents.

When recording ink is prepared using dyes containing such inorganic salts, the following disadvantages occur. That is,
Inorganic salts reduce the stability of dye dissolution in the ink, leading to aggregation and precipitation of the dye. Furthermore, in inkjet recording heads and writing instruments, if the ink evaporates near the ejection orifice and the liquid composition changes, this causes precipitation of inorganic salts. All of these are most likely to cause clogging of the discharge orifice, which should be avoided.

Therefore, in order to eliminate such adverse effects, it is necessary to control the concentration of inorganic monochromatic substances within a predetermined range (generally, 0.5% or less in the ink) during ink production. . This means that general commercially available dyes containing inorganic salts as impurities can be used in inkjet recording inks and
Indispensable when used for preparing ink for marking instruments.

[1] In view of the above, an object of the present invention is to remove the inorganic salts contained in the ink when preparing the ink, thereby making it possible to improve the inkjet recording ink, writing instrument ink, etc. Continuously supply purified dye solution suitable for the preparation of 1J
An object of the present invention is to provide a dye refining device that can perform the following steps.

[Embodiment] Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 shows an embodiment of the apparatus of the present invention.

Here, 21 is a dye supply section that stores dye powder 22, and supplies the dye powder 22 to a mixing tank 24 via a dye valve 23. In addition, a pure water valve 2 is provided in the mixing tank 24.
Pure water is supplied through the pure water supply pipe 2B in which a pipe 5 is inserted.

In this mixing tank 24, the supplied dye powder 22 and pure water are mixed and dissolved by a mixing tank agitator 27 to produce an aqueous dye solution. The amount of the aqueous dye solution stored in the mixing tank 24 is detected by a mixing tank liquid amount detector 28 . The aqueous dye solution obtained in the mixing tank contains particles of dye powder that were not dissolved in the pure water, and these are removed by the filter 29. This filter 29 has
Ordinary filter paper or Fluorobor (trade name) can be used. The aqueous dye solution from which particles and the like have been removed by passing through the filter 28 is supplied to the supply tank 31 .

The aqueous dye solution supplied to the supply tank 31 is supplied to the purification section described below via the supply pipe 32. Here, this supply tank 31 is provided with a valve 33 for controlling the liquid level to suppress the volume of the aqueous dye solution stored in the supply tank to below a certain level.

Next, reference numeral 41 is a distillation section V for removing inorganic salts from the aqueous dye solution, and a plurality of salt reduction processing units 42 (42-1 to 4
2-N). In the salt reduction processing unit 42, 4
3 (43-1 to 43-N) are supply valve opening/closing parts, 44 (
44-, 1 to 44-N) are salt reduction filter parts, and 45
(45-1 to 45-N) are discharge valve opening/closing parts.

The supply valve opening/closing section 43 includes a dye aqueous solution supply pipe 47 (4
7-1~47-N), pure water supply pipe 4El (46-1~
4El-N) and secondary solution supply pipe 48 (4B-1 to 4
8-N) respectively. Supply tank 3 for dye aqueous solution
1 to the opening/closing section 43 through supply pipes 32 and 47 in sequence, and pure water is supplied through supply pipes 26 and 46 in sequence.

Further, a secondary solution, which will be described later, is supplied from the secondary solution storage tank section 51 to the supply valve opening/closing section 4 through supply pipes 52 and 48 in sequence.
Supply to 3.

The supply valve opening/closing section 43 controls whether or not the supplied aqueous dye solution, pure water, and secondary solution are supplied to the salt reduction filter section 44 .

) In the acid salt filter section 44, by chromatography,
Inorganic salts are removed from the aqueous dye solution and secondary solution supplied from the supply valve opening/closing section 43.

By controlling the discharge valve opening/closing section 45, the concentration of inorganic salts is reduced to a predetermined value (for example, 5% for the dye) through such (salt reduction) purification.
The dye aqueous solution that has become less than
-1 to 55-N) to the storage tank 5B. Further, the aqueous solution discharged from the filter section 44 is transferred to the inorganic salt solution discharge section 58 or the discharge pipe 58 (59-N) via the discharge pipes 57 (57-1 to 57-N), depending on the component concentration.
1 to 511-N).

One end of this discharge pipe 58 is communicated with a suction port of a circulation pump 60, and the aqueous dye solution discharged into the discharge pipe 58 is passed through the discharge pipe 81 communicated with the discharge port of the pump 60 to two parts. The next solution is fed under pressure to the solution storage tank 51.

In this way, the dye aqueous solution refluxed from the discharge side of the purification section 41 is supplied as a secondary solution to the purification section 41 again, and (
Salt reduction) purification.

Next, 71 is a control section that controls the drive of each section, and 72 is an operation section that includes various display sections, drive switches, and the like.

Note that 73 and 74 are storage tanks 56 and 4.
11 is a discharge/help disposed in the discharge tank 58, and discharges the dye aqueous solution and the inorganic salt solution through these valves 73 and 74.

FIG. 2 shows the configuration of the acid salt treatment unit 42 (shown in FIG. 1).

In the figure, the first supply valve 431 in the supply valve opening/closing section 43 is controlled to open and close to control the supply of pure water to the salt reduction filter section 44 via the supply pipe 48 .

Similarly, the second supply pulp 432 and the third supply valve 43
2 to the salt-reducing filter section 44 by controlling the opening and closing of 3.
Control the supply of the next solution and the aqueous dye solution.

Next, the salt-reducing filter section 44 separates inorganic salts from the dye aqueous solution by chromatography. That is, an aqueous dye solution is supplied to one end of the chromatography column 441 from the supply valve opening/closing section 43. While the supplied aqueous dye solution descends within the column 441, each component in the aqueous solution is separated. Through such a developing operation (chromatography),
The components with the weakest adsorption properties flow out first. Therefore,
Based on the detection results, if the component concentration of the effluent solution is detected.

Of the effluent solution, only the aqueous dye solution whose inorganic salt concentration is below a predetermined concentration can be extracted.

Inorganic salt concentration detector 442 and dye concentration detector 443
is for detecting the concentration of inorganic salts and dye in the solution flowing out from the column 441, and is disposed in the flowing liquid passage 444 at the lower end of the chromatography column 441. Methods for detecting each component include methods that measure conductivity, methods that use ionic current, and methods that measure spectrophotometry.

Either is fine.

A dye solution is supplied to the chromatography column 441 in fixed amounts for purification (salt reduction).For this purpose, a liquid level position detector 445 is installed at the upper end of the column to detect the dye solution. Based on the result, the supply of the aqueous solution from the supply valve opening/closing section 43 is controlled.

Here, as the stationary phase filled in the column 441, there are generally ion exchange resins, Kiley-1 resins, etc., but in this example, ion retardation resins, such as Retardion II resin, are used.
A-8 (trade name: manufactured by Dow Chemical Company) is used. Ion retardation resins do not require regeneration agents and can be regenerated with pure water, and since the resins are nearly neutral, they are advantageous for desalting substances that are unstable to acids and alkalis.

FIG. 3 shows an outflow curve in which the concentration of each component of the outflow solution from the chromatography column 441 is plotted against the time axis, that is, the fractionation characteristics. As shown, Somene 1 concentration (curve ■)
peaks between hours 11 and 12, and the inorganic salt concentration (curve ■) peaks between hours 73 and 74. In this example,
Based on such classification characteristics, the inorganic salt concentration detector 44
2 and the detection value of the dye concentration detector 443, the effluent solution from the chromatography column 441 is fractionated and extracted as follows.

That is, when the dye concentration of the effluent solution is equal to or higher than the predetermined value C2 (effective dye concentration) and the inorganic salt concentration is less than the predetermined value 03 (allowable inorganic salt concentration) (between times 11 and 12), the effluent solution is transferred to the storage tank. Leads to 56. However, after the inorganic salt concentration exceeds the value C3 and the dye concentration falls below the value C2, the effluent solution is directed to the inorganic salt solution discharge tank 58. Also,
During the period from when the inorganic salt concentration reaches the value C3 or higher until the dye concentration decreases to the value C2 or lower (between times 72 and 73), the effluent solution is refluxed to the secondary solution storage tank 51.

Referring again to FIG. 2, the discharge pulp opening/closing section 45 separates the effluent solution as described above, and the discharge pulp opening/closing section 45 separates the effluent solution from the outflow passage 444.
is branched into three prongs, and each branch pipe and discharge pipe 57, 59 and 55 are connected to the first pipe. They are communicated via second and third υ1 output valves 451, 452 and 453. With this configuration, by opening the first discharge valve 451, the effluent solution can be discharged to the inorganic salt solution discharge tank, and similarly, by opening the second and third discharge valves 452 and 453, the effluent solution can be discharged, respectively. Secondary solution storage tank 5
1 and storage tank 56.

FIG. 4 shows the control system of the equipment shown in FIG. here 10
Reference numeral 1 denotes a controller, which controls the drive of each part. 10
Reference numeral 2 denotes a read-only memory (ROM), which stores a control program such as the operating procedure shown in FIG. A random access memory (RAM) 103 temporarily stores various data.

Reference numeral 104 denotes various switches arranged in the operation unit 72, which send various command signals to the controller 101 via an input/output buffer circuit 105. Reference numeral 106 designates a display device similarly disposed on the operation unit 72, and reference numeral 107 designates a drive circuit that controls the display of the display device 106 based on a drive signal from the controller 101.

In this example, analog signals are output from the inorganic salt concentration detector 442 and the dye concentration detector 443, and are converted into digital signals via A/D converters 111 and 112, respectively, and then sent to the input buffer circuit 113. The signal is supplied to the controller 101 via the controller 101. On the other hand, a digital signal is output from the liquid level position detector 445, and the input buffer 7 circuit 113
The signal is supplied to the controller 101 via.

121 to 126 are each valve 431, 432 mentioned in 111
, 433.

These are drive circuits for opening and closing 451, 452, and 453, respectively, and are controlled to be turned on or off by a drive signal supplied from the controller 101 to the outlet/sofa circuit 127.

In addition, since the salt reduction processing units) 42-1 to 42-N have the same configuration, only the unit 42-1 is shown in the figure, and the other units) 42-2 to 42-N are omitted. It is.

FIG. 5 shows the operation of each processing unit in this embodiment configured as described above.

In the figure, when a start command is received from the operation unit 72 in step STI, the program switch is set to OFF in step ST2. Next, in step ST3, the second and third supply valves 432 and 433 are opened to start supplying the dye aqueous solution in the supply tank 31 and the secondary solution in the secondary solution storage tank 51 into the chromatography column 441. This supply operation continues until the liquid level in the column 441 reaches the highest position H (see FIG. 2) according to the output of the liquid level position detector 445 in step ST4. When the liquid level height H reaches the maximum position, that is, when a predetermined amount of aqueous solution has been supplied to the column, step ST
5, both valves 432 and 433 are closed.

Next, in step ST6, the first exhaust valve 451
is opened, and the effluent solution from the chromatography column 441 begins to be discharged to the inorganic salt solution discharge tank 5th.

In step ST7, it is determined whether the liquid level in the column is at the lowest position (see FIG. 2). Immediately after supplying the dye aqueous solution and secondary solution,
The liquid level is above the lowest position, so select "NO"
It is determined that this is the case, and the process proceeds to step ST8. In step ST8, the first supply valve 431 is closed, and the process proceeds to step 5TIO. Here, as described above, immediately after the dye aqueous solution and the secondary solution are supplied and the developing operation is started in the column 441, the concentration of each component of the effluent solution is shown between times 0 and 71 in FIG. in a state. Therefore, in step 5TIO, the dye concentration detector 44
The determination as to whether or not the density value detected in step 3 is greater than or equal to the effective dye density value C2 is "NO", and step 5TI
Proceed to I. Furthermore, in step 5TII, the determination as to whether the concentration value detected by the organic salt concentration detector 442 is equal to or greater than the cleaning inorganic salt concentration value 01 is determined as "NO", and the process proceeds to step 5T12. Step! At 3T12, it is determined whether the program switch is in the on state. In the first loop, since it is in the off state, the determination is "NO" and the process returns to step ST7. Such steps ST7→ST8→5rto
+ 5TII → 5T12 loop is step 5TIO
This process is repeated until rYESJ is determined.

Note that when it is determined as rYES J in step ST7, the process proceeds to step ST8, the first supply valve 431 is opened, and pure water is supplied to the column 441.

Therefore, in such a case, steps ST7→ST9→5
A loop of TIO→5T11+5T12 is executed.

In step 5TIO, when the dye concentration value of the solution flowing out from the column 441 becomes equal to or greater than the effective dye concentration value 02 (time T1 in FIG. 3), the process proceeds to step 5T13. Step 5
At T13, it is determined whether the inorganic salt concentration value detected by the inorganic salt concentration detector 442 is an allowable inorganic class M concentration (f403 or higher).

Here, due to the development operation of the chromatography column 441, the dye aqueous solution separated from the inorganic salts flows out first (the third
(Refer to the time table 1 to T2 in the figure), and in step 5T13, "N
The result is ``O'', and the process proceeds to step 5T14. In step 5T14, the first discharge valve 451 is closed, and in step 5T15, the third discharge valve 453 is closed.
When the opening operation is performed, the effluent solution from the chromatography column 441 is discharged to the storage tank 56 through the publication pipe 55. Next, in step 5T113, the program switch is turned on, and the process returns to step ST7. Such steps ST7→ST8→5TIO-5T13→5T14→5T
15→5T1B or step ST? →ST8→5T1
The loop of 0 → 5T13 → 5T14 → 5T15 → 5T18 is repeated, and an aqueous dye solution whose inorganic salt concentration is purified to below the allowable value C3 is obtained in the storage tank 58. This loop continues until rYESJ is determined in step 5T13.

As shown in FIG. 3, the inorganic salts begin to flow out and the inorganic salt concentration of the effluent solution increases, and when the value becomes equal to or higher than the allowable inorganic salt concentration value C3 (time T2 in FIG. 3), step 5T13 The process then proceeds to step 5T17, in which the third discharge valve 453 is closed, and in step 5TI8, the second discharge/help 452 is opened. As a result, the effluent solution is transferred to storage tank 5.
The discharge to the discharge pipe 58 is stopped and discharged to the discharge pipe 58. Here, in this example, assuming that the circulation pump 60 is driven in synchronization with the opening operation of the valve 452, the outflow solution is transferred to the discharge pipe 59.
．． It is discharged to the secondary solution storage tank 51 via θ1. This refluxing operation of the effluent solution is performed in step 5TIO as follows.
The process continues until the determination is NO. The secondary solution recovered in this way will be purified again to reduce salt. Next, when the dye concentration of the effluent solution decreases and its value becomes less than the effective dye concentration value C2 (time T3 in FIG. 3), a determination of "NO" is made in step 5TIO, and step! 9T
Proceed to step 11. Now, since inorganic salts are continuing to flow out, it is determined that rYEsJ is present in step 5T11, and the process proceeds to step 5T19, in which the second discharge valve 452 is closed, and furthermore, in step 5T20, the first discharge valve 451 is opened. Ru. As a result, the effluent solution is 2
The reflux to the next solution storage tank 51 is stopped, and the solution begins to be discharged to the inorganic salt solution storage tank 58 via the discharge pipe 59. This draining operation is continued until the inorganic salt concentration of the effluent solution falls below the cleaning inorganic salt concentration value C1.

When the inorganic salt concentration falls below the value C1 (time T4 in Figure 3)
, it is determined in step 5TII that the result is rNOJ, and the process proceeds to step 5T12. Here, since the program switch is set to ON in step 5T18 as described above, rYES J is selected in step 5T12.
It is determined that the process proceeds to step ST21, the first discharge valve 451 is closed, and the discharge of the outflow solution to the discharge tank 5B is completed.

Next, in step 5T22, the supply valve 431 is closed, and the supply of pure water to the chromatography column 441 is stopped. That is, in this example, the first supply valve 431 is controlled to open and close so that the liquid level of the aqueous solution in the chromatography column 441 is always at the lowest position (see FIG. 2), and pure water is supplied (step ST8). , 5T9). This pure water washes (regenerates) the stationary phase within the chromato column. ” When the inorganic salt concentration of the effluent solution falls below the cleaning inorganic salt concentration CI, as in the case of two series, cleaning (regeneration) is performed.
It is determined that this has occurred, and the supply of pure water is stopped.

After executing step 5T22, step STI is executed again.
Return to and wait for the start command.

One (salt reduction) purification operation is completed as described above. Note that in this embodiment, each processing unit 42-1
Although the operations from 42-N to 42-N are executed synchronously, the operations are not limited to this, and may of course be executed sequentially, for example.

Further, in this embodiment, the collected secondary solution is purified in each processing unit 42, but a separate processing unit exclusively for the secondary solution may be provided to perform the purification.

[Effects] As explained above, according to the present invention, dye dissolution! In producing fb, purification of the dye by chromatography,
That is, since the inorganic salts contained in the dye solution are excluded, a purified dye solution suitable for preparing Infusiella I recording ink, writing instrument ink, etc. can be produced.

Furthermore, according to the present invention, such a dye solution can be produced continuously and automatically, making it possible to produce high-quality dyed dog products.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of the apparatus according to the present invention, and FIG. 2 is the salt reduction treatment unit shown in FIG. 1!・A configuration diagram showing
Figure 3 is a characteristic curve diagram showing the separation characteristics of the chromato column.
FIG. 4 is a block diagram showing the control section of the device shown in FIG. 1;
FIG. 5 is a flowchart showing the operation of the salt reduction processing unit of the apparatus shown in FIG. 21... Dye supply unit, 22... Dye powder, 23... Dye valve, 24... Mixing tank, (19) 25... Pure water valve, 26... Pure water supply pipe, 27 ...Mixing tank stirrer 28...Mixing tank liquid level detector, 29...Filtration filter, 31...Supply tank, 32...Supply pipe, 33...Valve, 41...Refining Parts, 42... Salt reduction processing unit, 43... Supply valve opening/closing part, 44... Salt reduction filter part, 45... Discharge valve opening/closing part, 46... Dye aqueous solution supply pipe, 47...・Pure water supply pipe, 48...Secondary solution supply pipe, 51...Secondary solution storage tank, 52...Supply pipe, 55...Discharge pipe, 58...Storage tank, (20) 57...Discharge pipe. 58... Inorganic salt solution discharge tank, 59... Discharge pipe, 60... Circulation pump, 61... Discharge pipe, 71... Control section, 72... Operation section, 73.74... - Discharge valve, 101... Controller, 102... Read only memory, +03... Random access memory, 104... Switch, 105... Input/output buffer circuit, 108... Display, 107 ...Drive circuit, 111.112...A/D converter, +13...Input buffer circuit, 121-12fl...Drive circuit, 127...Output buffer circuit, 431.432, 43.3・・・A 6 valve valve, 4
41... Chromato column, 442... Inorganic salt concentration detector, 443... Dye concentration detector, 444... Outflow passage, 445... Liquid level position detector, 451, 452, 453...・Exhaust valve.

Claims (1)

[Claims] It is characterized by comprising a means for producing a dye solution, a means for processing the dye solution for performing chromatography using the solution, and a detecting means for detecting the concentration of inorganic salts in the solution discharged from the processing means. Dye purification equipment.