JPS6072962A - Apparatus for purifying dye - Google Patents

Abstract

PURPOSE:To obtain ink suitable for use in ink jet recording, writing utensils, etc., by removing inorg. salts contained in a dye soln. by means of a membrane and then removing heavy metal ions by means of an ion exchanger. CONSTITUTION:A dye powder 5 within a feed part 3 is fed to a mixing tank 9, where the powder is dissolved in pure water fed through a pipe 13. The resulting dye soln. is filtered through a filter 19 to remove insoluble matters, fed to a feeding tank 21 and fed through a feed pipe 23 to the salt-reducing tank 101 of a purifying part 100A. The dye soln. is circulated through a membrane filter 103 such as an ultrafiltration membrane or a reverse osmotic membrane by operating a circulating pump 115 to remove inorg. salts and introduced into the feed tank 161 of a purifying part 100B. The dye soln. is then fed to an ion exchange resin column 169 to remove heavy metal ions and then discharged through a discharge valve 177 to a reservoir 179.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a dye purification device, and in particular to a method for purifying a purified dye suitable for TLF for preparing a recording liquid (generally referred to as an ink) suitable for inkjet recording, writing instruments, etc. This relates to a dye refining device for continuous production.

[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 dissolve or incubate in a liquid medium consisting of:

Also, similar ink can be used for writing instruments such as felt pens and pens. is known to be used.

An example of a single-unit configuration of such ink (general) is as follows:
The main ingredients include water-soluble dyes, water as a solvent thereof, and glycols as anti-drying agents.

Here, the water-soluble dye usually contains a large amount of non-42 salts such as sodium chloride and sodium sulfate, and heavy metal ions.

When recording inks are prepared with dyes containing inorganic salts and heavy metal ions, the following disadvantageous #\ state occurs. That is, inorganic salts and heavy metal jtN ions reduce the dye dissolution stability in the ink, resulting in aggregation and precipitation of the dye. Furthermore, in ink-shet recording pens and writing instruments, if the ink evaporates near the ejection orifice and the liquid composition changes, this causes precipitation of inorganic salts and heavy metals. All of these causes clogging of the discharge orifice, which is most avoided.

Therefore, in order to eliminate such adverse effects, it is necessary to control the concentrations of inorganic salts and heavy metal ions within predetermined ranges during ink production. This means that general commercially available dyes containing inorganic class 11 and heavy metal ions as impurities can be
((When used for preparing ink for marking utensils, it is indispensable.

[Objective] In view of these points, the object of the present invention is to remove inorganic salts and heavy metal ions contained in a dye solution by a membrane separation method and an ion exchange separation method, thereby making it suitable for inkjet recording, writing instruments, etc. An object of the present invention is to provide a dye purification device capable of producing a dye solution suitable for preparing ink.

[Example] The invention will now be described in detail with reference to one drawing.

FIG. 1 shows the overall configuration of an embodiment of the apparatus of the present invention.

Here, ■ is a production department that manufactures an aqueous dye solution, and +00 is a purification department for the aqueous dye solution, a purification department 100A that removes inorganic salts by a 1j separation method, and a purification department 100A that removes heavy metal ions by an ion exchange separation method. Refining section 100B
has. Reference numeral 300 denotes a control section, which controls the driving of each section described above.

FIG. 2 shows the structure of the dye solution production 7iRl of FIG. 1.

Here, 3 is a dye supply section that stores dye powder 5,
The dye powder 5 is supplied to the mixing tank 8 through the dyeing 4"18 valve 7. Pure water is also supplied to the mixing tank 8 through the pure water supply vibrator 13 in which a pure water valve 11 is inserted. .

In this mixing tank 8, the supplied dye powder 5 and pure water are mixed and dissolved by a mixing tank agitator 15 to prepare an aqueous dye solution. The amount of the aqueous dye solution stored in the mixing tank 9 is detected by a mixing tank liquid amount detector 17. In the aqueous dye solution obtained in the mixing tank, some particles of the dye powder that were not dissolved in the pure water remain, and these are removed by the filter 19. For this filter 19, ordinary filter paper or Fluorobor (trade name) or the like can be used. The dye aqueous solution from which particles and the like have been removed by passing through the filter 19 is supplied to the IJ (ship inspection 21).

The aqueous dye solution supplied to the supply tank 21 is supplied to the purification section 100, which will be described next, via the supply pipe 23. Here, this supply tank 21 is provided with a valve 25 for controlling the liquid level,
The amount of dye aqueous solution stored in the supply tank is kept below a certain amount.

FIG. 3 shows a purification section 100A that removes inorganic salts from the aqueous dye solution in the purification section 100 of FIG. In the figure, 101 is a salt reduction tank, +03 is a salt reduction filter, and 10
5 is a salt removal tank. Supply valve 107 for salt reduction tank +01
The aqueous dye solution is supplied through the . The supplied dye aqueous solution is stirred by the salt reduction tank stirrer 109 to homogenize the aqueous solution, and the inorganic salt concentration in the aqueous solution is detected by the inorganic salt concentration detector 111. This concentration detection is performed, for example, by ion chromatography. Further, a dye concentration detector 113 detects the dye concentration in the aqueous solution. This concentration detection is performed, for example, by spectrophotometry. As will be described later, inorganic 1) Category 1 agricultural rate is specified i + ti (for example, 5 layers, 11% for dye'1)
) or more is detected, the circulation pump +1
5 is activated to circulate the dye aqueous solution in the salt reduction tank through the salt reduction filter 103. As this if<'Xm filter, for example, an ultrafiltration filter or a reverse osmosis filter is used. By passing through the salt-reducing filter 103, inorganic jJLs such as sodium chloride and sodium sulfate contained in the aqueous dye solution are filtered from the aqueous dye solution and discharged into the salt removal tank 105.

In this way, a part of the water, which is the substance of the dye, is discharged into the salt drainage tank 105 along with the inorganic salts. Therefore, this drained water was replenished into the dye solution 4 nights, and
Desired J? in the salt reduction tank 101? The acupuncture salt bath 101 is passed through the pure water valve +17 so that a dye aqueous solution of grade A is obtained.
supply pure water.

In this way, an aqueous dye solution having an inorganic salt concentration and a dye concentration within a predetermined range is obtained in the salt reduction tank 101. Detected by the salt tank liquid star detector 119.
:il&JK') The purified aqueous dye solution is supplied to the supply tank 181 of the purification section 100B, which will be described below, via the storage valve 121.

FIG. 2'S4 shows the configuration of the purification section 100B that removes heavy metal ions from the dye aqueous solution in the purification 7fB100 shown in FIG.

Here, the aqueous dye solution from which R-free salts have been removed in the purification section 100A is supplied to the supply tank 1131. A supply tank liquid level detector 1f13 is installed in this supply tank 161, and based on this output, the valve +21 is opened and closed to control the supply tank til.
Controls the liquid level height within l.

The refining section 100B includes a plurality of processing units, in this example, three first to third processing units 1f (5-1, 1f15-2).
and 185-3. Each processing unit H35 (1
65-1~! 85-3), the aqueous dye solution in the supply tank 181 is supplied to the supply valves 187 (1f17-1 to 187-
3) through the ion exchange resin column 169 (169-1
~189-3). Ion exchange resin column +8
9 fractionates heavy metal ions from the dye aqueous solution by so-called ion exchange separation. That is, due to ion exchange within the column, pions are captured by the ion exchange resin and remain in the column by the highly absorbent heavy metal contained in the aqueous dye solution. Here, valves 17+ (171-1-171-3) for controlling the liquid level are provided in the column to control the amount of the aqueous dye solution supplied into the column. Further, this column 168 is made removable from the processing unit, and whether the column is attached or not is detected by a filter replacement end switch (not shown).

Next, heavy metal ion concentration detector 173 (173-1 to 17
3-3) is placed in the outflow solution passageway at the lower end of column 1θ9 to detect the heavy metal ion concentration in the outflow solution from column 169. As a method for detecting the heavy metal ion concentration, for example, a measurement method using a metal ion electrode or a measurement method using atomic absorption spectroscopy is used. Solution detector 1
75 (175-1-175-3) are similarly disposed in the outflow solution passage to detect the presence or absence of the outflow solution in the outflow solution passage.

The effluent solution from column 1139 is transferred to first discharge valve 177.
<177-1 to +77-3) to the storage tank 179. Also, 2nd grab/help 18m81-1-1
81-3), by the action of the circulation pump 183,
The liquid is returned to the supply tank 161. Opening/closing control of both valves 77 and 181 is performed based on the detection results of the small metal ion concentration detector 173 as described later.

In this way, there is no # in the storage tank 17Q! A purified dye solution is obtained from which salts and heavy metal ions have been removed. This aqueous solution is taken out via the supply valve 185 and used for preparing ink.

FIG. 5 shows a portion related to the purification section 100A in the control section 300 of the apparatus shown in FIG.

In the figure, 301 is a controller that controls the drive of each part. 302 is a read-only memory (ROM) in which control programs such as the operating procedures shown in FIGS. 7 and 8 are stored. 303 is random access memo □
(RA)I), where various data are temporarily stored.

In this example, analog signals are output from the inorganic salt concentration detection section 111 and the dye concentration detector 113, and after being converted to decile signals via A/D converters 304 and 305, respectively, The signal is supplied to the controller 301 via 308. - power, salt reduction tank liquid star detector 11
A digital signal is output from 9, and a large power 4FFA circuit 3
It is supplied to the controller 301 via 0B.

307 to 311 are the aforementioned valves 117, 107, 1
21, a drive circuit for driving the stirrer 108, and the circulation pump 115, respectively, and the controller 301
On/off control is performed by a drive signal supplied from the output buffer circuit 312 through the output buffer 7 circuit 312.

321 and 322 are a dye concentration range setting switch and an inorganic salt concentration range setting switch, respectively, and signals corresponding to the set concentration range are sent to the input/output buffer circuit 3.
23 to the controller. 3248 and 325
are a dye concentration indicator and an inorganic salt concentration indicator, respectively, and display the dye 'I value and the inorganic salt concentration 4ti in the aqueous dye solution being purified. Therefore, the operator of the ink manufacturing apparatus can easily know the quality of the ink being manufactured.

Setting of the dye concentration range and inorganic salt concentration range by the switches 321 and 322 (di is temporarily stored in the RAM 303. ty> Each detected concentration value of inorganic salts and dyes is
The comparison unit 313 of the ili controller compares it with the set value, and based on the comparison result, the circulation pump 1
The driving of each load such as 15 is controlled.

FIG. 6 is a diagram of the control unit 300 of the apparatus shown in FIG. The drive circuits 332 and 333 are the output buffer circuit 3
Each load (valve 185, pump 183) is controlled to be turned on or off based on a drive control signal from the controller 301 supplied via the controller 34.

335 is various switches, human output 8977 circuit 33
Various command signals are sent to the controller 301 via the controller 6. 3
37 is an indicator, as described later, purification 131008
The first to third units/filter replacement indicators display that the columns in each processing unit need to be replaced, and the first to third units display that each processing unit is in the process of purifying the dye aqueous solution. It has three units operating indicators. A drive circuit 338 controls the display of the table j1\ device 337 based on the drive signal from the controller 301.

Next, the detection signal from the heavy metal ion concentration detector 173-1 is digitized via the A/D converter 341 and then supplied to the controller 301 via the input buffer T circuit 342. Further, a digital detection signal is output from the solution detector 175-1 and is supplied to the controller 301 via the input 71727 circuit 342. 343°344 and 34
5 is a drive circuit for opening and closing each of the above-mentioned valves 187-1, 177-1 and 181-1, and is output from the controller 301. <On/off control is performed by a drive signal supplied via the Zuffer circuit 348.

Note that the configurations of each processing unit 185-1 to 165-3 are the same, so in the figure, other units 165-2
1B and 185-3 shall be omitted.

FIG. 7 shows the operating procedure of the dye solution manufacturing section 1 and purification section 100A of this embodiment configured as described above. In the figure, step 5TI-3T4 maintains the dye aqueous solution in the mixing tank 3 at a constant amount. It is a procedure. Sunao)chi procedure S
In TI, from the output of the mixing tank liquid level detector 17, the mixing tank 9
The liquid level of the aqueous dye solution in the container is above the low position that defines a predetermined setting range.In this case, proceed to step ST2, otherwise proceed to step ST30 step ST2
Now, the dye valve 7 and the pure water pulp 11 are opened, and predetermined amounts of dye powder and pure water are respectively put into the mixing tank I7. In the mixing tank 3, the stirrer 15 is constantly in operation, so the dye powder introduced is dissolved in pure water.
In step S3, in which an aqueous dye solution is prepared, it is detected based on the output of the liquid amount detector 17 whether or not the liquid level in the mixing tank 8 is higher than a high-grade product that defines a set range. If it is higher than the high-grade product, proceed to step ST4k; otherwise, proceed to step ST5. In step ST4, the dye valve 78 and pure water valve 13, which are in the open state, are closed to stop the supply of dye powder and pure water.

In step ST5, the dye concentration (lf
4 is displayed on the display 324. In procedure STe.

Similarly, the inorganic salt concentration value detected by the inorganic salt concentration detector 111 is displayed on the display 325.

7-y%I+ It is determined whether or not the dye concentration r-1 excluded by Kusunoki 113 is within the dye concentration range set by the switch 321. If it is determined that it is within the setting range, proceed to step ST8, otherwise proceed to step ST9.
It is determined whether the concentration of inorganic salts detected by a111 is within the range of values set by switch 322. If it is determined that it is within the set range, the process proceeds to step 5TIO, and if not, the process proceeds to step ST9.

In step 5TIII, it is determined whether the liquid level in the salt reduction tank 101 detected by the detector 111 is above a high position that defines the setting range. If it is below that height,
Proceed to step 5Tll, if not, move +111t
Proceed to ST12 In step S11, supply valve 1078
The aqueous dye solution and pure water are supplied into the salt reduction tank 101 by controlling the opening and closing of the pure water valve l17. As a result, the dye concentration in the aqueous dye solution in the salt reduction tank 101 is adjusted to be within the range set by the switch 321 as described above. After this, proceed to step 1 5T13. On the other hand, in step 9 12, supply valve 32 and pure water valve 11
? performs the closing action.

In step 5T13, the circulation pump 115 is operated to circulate the aqueous dye solution in the salt bath 101 through the salt-reducing filter 103 to remove inorganic salts from the aqueous dye solution.

As mentioned above, if the dye concentration and inorganic salt concentration are outside the set range, repeat the routine of step 5TII and step ST+3 or step 5T12 and step 5T13 to bring the dye concentration and inorganic salt concentration to values within the set range. Nasu. After the image density is within the set range, proceed to step 5T.
Proceed to step 10.

In step 5TIO, it is determined whether the liquid level in the salt reduction tank 101 detected by the detector +19 is above the low position that defines the setting range. If it is above the low position, the process proceeds to Step 1 5T14; otherwise, the process proceeds to Step 5T15. In Step 5T14, the operation of the circulation pump 115 is stopped and the valve 121 is opened.

As a result, the purified dye aqueous solution of the predetermined II) obtained in the salt reduction tank 101 is supplied to the supply tank 181 of the purification section 100B.

In step 5T15, the valve 121 is closed and the supply valve 107 and the pure water valve 117 are opened to terminate the supply to the purification section 100B, and at the same time, the salt reduction 4f41
Increase the amount of dye aqueous solution in 01 so that the liquid level is within the set range.

Thereafter, repeating the routine of steps 5TII and 5T13 or manual injection 5T12 and 5TI3 described above, a predetermined amount of the dye aqueous solution whose dye concentration and inorganic salt concentration are within the set range is placed in the salt reduction tank 101. can get.

After this, the process proceeds to step 5T14 described above.

As mentioned above, in this embodiment, the purification section 100A
In this process, the dye aqueous solution is purified at regular intervals, and the dye aqueous solution from which #1 salts have been removed to a predetermined concentration or less can be continuously supplied to the purification section 100B.

FIG. 8 shows the operation of each processing unit in the refining section 100.

In the purification section 100B, each processing unit 185-1 to 11
35-3 are replaced one after another to remove heavy metal ions from the dye aqueous solution supplied from the purification section 100^. That is, there is a limit to the ability of the ion exchange resin in the ion exchange resin column 189 to capture heavy metal ions, and once a certain amount of heavy metal ions are absorbed, ion exchange separation is not performed thereafter. As a result, the dye solution containing heavy metal ions is discharged as is, and the concentration of heavy metal ions in the solution flowing out from column 169 increases. This increase in concentration is detected, the ion exchange resin column is made unusable, and the subsequent purification of the dye solution is performed using one of the other two columns. The column is replaced with a new column or the ion exchange resin is regenerated so that purification can be performed again in the processing unit. FIG. 8 shows the operation in each processing unit, and each flag in the figure is for making the following determinations.

Unit filter replacement flag: This flag instructs to replace the filter in each processing unit, that is, the ion exchange resin column. When this flag is turned on, the corresponding unit filter replacement indicator will display that the filter needs to be replaced. Ru.

Unit change request flag: This flag requests a change in processing unit. When this flag is turned on, the processing unit indicated by the unit selection counter is selected and the dye refining operation is transferred to that processing unit.

Unit operation flag: A flag indicating that the corresponding processing unit has been translated.

Unit in operation flag: A flag indicating that the corresponding processing unit is in operation.

Unit discharge flag 2 This is a flag that turns on when the concentration of heavy metal ions in the solution flowing out from the column in the corresponding processing unit exceeds a set value, and instructs the pump 183 to start refluxing the solution flowing out to the supply tank 181. do.

Next, each procedure shown in FIG. 8 will be explained.

In FIG. 8(A), in step 5 TIOI, each display and data are initialized. In step 5T102, the processing unit change request flag is turned on, and the contents of the unit selection counter are set to "1". In step 5T103,
Based on the detection output of the supply tank liquid level detector 183, it is determined whether a predetermined amount of dye aqueous solution is stored in the supply tank 181. When the predetermined amount is stored, the dye solution supply valve 133 is closed in step 5T104, and then step 5T1 is performed.
However, if the predetermined amount has not been reached, the supply pulse 133 is opened in step 5T105 to supply the aqueous dye solution to the supply tank.

Step 5T108 is a processing procedure when there is a filter replacement request in the first processing unit l-185-1.
108-1-3 TIOI (consists of -3. First, move 11
1i1ST106-1 determines that the first unit filter replacement flag is on, 1S
Proceeding to TI08-2, it is determined whether the first unit filter replacement end switch is on. If it is in the ON state, the process advances to step 910B-3, where the IT unit filter replacement flag is turned off and the display indicating that replacement is required, which was displayed on the first unit filter replacement display, is erased. After this, step 5 TIO? Proceed to. Note that when the filter replacement flag is off in step 5T108-1 and when the filter replacement end switch is off in step 5T1011-2, the process proceeds to step 5T107 following the flow of "NO".

Step 5T10? and step 5T108 are the second
Processing 22, l-185-2 and third processing unit H
This is a processing procedure when there is a filter replacement request in 35-3, and the contents thereof are the same as those in f-order 5T1013, so the explanation thereof will be omitted.

In step 5T109, it is determined whether or not the unit change request flag is in the ON state, and if it is determined to be a job offer, move 1 is selected.
Proceed to 1+n5T110, if negative judgment, Fig. 8+',
B) Proceed to step 5T118 In step 5TIIO,
The contents of the unit selection counter are determined and the contents are r
When it is lJ, the process advances to step 5T113, when it is "2", it goes to step 5rlta, and when it is "3", it goes to step 5T115.

Steps 5T113 to 5T115 are performed in each processing unit l-185.
This is a processing procedure when -1 to 185-3 is selected.

Since the contents of each of these steps 5T113 to 5T115 are the same, the contents of step 5T113 when the first processing unit 1135-1 is selected will be explained. First, step 5T11
In step 3-1, it is determined whether the first unit filter replacement flag is in the off state. If the judgment is negative, proceed to step 5T.
Proceed to 113-5, and if it is a fixed judgment, step 5T113-2
Proceed to. In step 5T113-2, the first unit operating indicator is turned on to indicate that the first processing unit, unit 185-1, is operating. Hand 11114 S T 1
At 13-3, the supply valve 1f17-1 and the 4'S2 discharge valve 1811 are opened.

Subsequently, in step 5T113-4, the first unit operation flag is turned on, and the unit change history expense request flag is turned off. Next, in step 111R5T113-5, after setting the content of the unit selection counter to "2", 1 step 5T1
Proceed to 1G, where the unit selection counter is a ring counter whose contents change in the order of r2'', r3'', rl'', r2'', etc.
By executing step 4, the content changes to r3 J, and by executing step 5T115, the content changes to rl'J.

Next, step 5T1113.5T11 of JJ8 figure (B)
7 and 5Tl18 are discharge control steps for the ejected solution from the ion exchange resin column in each processing unit I, respectively. The content of each of these steps is the same, so 1
Procedure S showing control in 1 processing unit 165-1
The contents of only T I 18 will be explained.

First, in step 5TIIf(-1, it is determined whether the first unit operation flag is in the on state or not. If the determination is negative, proceed to step 5T116-5, and if the determination is 11, proceed to step 5T118-2. Procedure In ST!16-2, it is determined whether the +J (gold kg 1f ion concentration in the column outflow solution detected by the gold kg ion 1 seismic intensity detector 173-1 is below a set value.

If the determination is negative, the process proceeds to 1,000 W4s-me-s, and if the determination is affirmative, the process proceeds to step 5T118-3. In step 5T118-3, the second discharge valve 1811 is closed, and the first discharge valve +
Open 77-1. As a result, ion exchange resin column +1
In 39-1, the concentration of heavy metal ions is below the set value i1
The aqueous dye solution removed up to
7, I is discharged into the storage tank 178. Next, in step 5Tl18-4, the first unit operation flag is turned off, and the first unit operation flag is turned on, and then step 571
Proceed to 1B-5.

In step 5T118-5, it is determined whether the first unit operating flag is in the on state.

If it is in the off state of 1 m, the process proceeds to step 5T116-10, and if it is in the on state, the process proceeds to step 5T11B-8. Step 5Tl18
-6, it is determined whether the concentration detected by the heavy metal ion concentration detector 173-1 exceeds a set value. If the set value is not exceeded, proceed to step 5T118-10.
Proceed to 1M! If so, proceed to step 5Tll13-7. After turning off the first unit operating indicator in step 5711fi-7, proceed to step 5T1113-8, where the supply valve 187-1 and the first discharge valve +77-1 @
close. Further, a reflux operation is performed in which the second discharge valve 181-1 is opened and the circulation pump 183 is driven to return the effluent solution from the column I6'a-1 to the supply tank 1fil via the second discharge valve +81-1. is started. Next, in step 5T10B, after turning off the first unit operating flag and turning on the H+1 unit discharge flag,
Proceed to step 5T1113-10.

Next, in step ST+18-10, it is determined whether or not the first unit discharge frac is in the ON state. If it is in the OFF state, the process proceeds to step 5T117, and if it is in the ON state, the process proceeds to step 5T1113-11. . In step 5T118-11, it is determined whether the solution detector +75-1 installed in the outflow solution passage of column 1139-1 is off, that is, whether there is any C outflow solution remaining in the outflow solution path. It will be judged.

When it is not in the OFF state, that is, when a solution is detected, the process proceeds to step 5T117, and when it is in the OFF state, the process proceeds to step 5Tl16-12. This off state means that all of the aqueous dye solution discharged from the column If(!)-1 whose heavy metal ion I concentration value is higher than the set value has been refluxed to the supply tank 181. Procedure 5Tll13-1
In Step 2, the first unit filter replacement indicator is turned on to indicate that the column of the first processing unit needs to be replaced.Next, in Step 5T118-13, the second discharge valve +81-1 is closed and , the drive of pump +83 is stopped, and the reflux operation is stopped.

Next, in step 5T116-14, the first unit discharge flag is turned off, the first unit filter replacement flag is turned on, and the unit change request flag is turned on. After this, the process advances to step 5T117.

Next, step 5T11? and after 5Tl18, 11
) and return to step STIθ3 shown in FIG. 8(A).

By executing each of the above steps, each processing unit y)
+135-1'' The aqueous dye solution is purified or drained in step 185-3, and the purified aqueous dye solution whose heavy metal ion concentration is below the set value is delivered to the storage tank 179.

In this way, a purified aqueous dye solution from which inorganic salts and heavy metal ions have been removed is obtained in the storage tank 178 by the purification units 100A and 100B, and the required amount of water is obtained in the storage tank 178. The aqueous solution will be taken out via valve 185 and used for ink preparation.

[Effect] As explained above, according to the present invention, the inorganic salts contained in the dye solution are removed by 1 part by carrying out the 11 separation method, and the inorganic salts contained in the dye solution are removed by carrying out the ion exchange separation method. Since heavy metal ions are removed, it is possible to produce a dye solution suitable for preparing inks for use in inkjet recording and writing instruments.

Furthermore, according to the invention, such purified dye solutions can be produced continuously and automatically.

In the above example, the dye solution was purified by removing inorganic salts by performing a membrane separation method and then removing heavy metal ions by performing an ion exchange separation method. Of course, the opposite may be true.

[Brief explanation of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the apparatus according to the present invention, FIG. 2 is a configuration diagram showing the dye solution production section of FIG. 1, and FIG. 3 is an inorganic salt purification section in the purification section of FIG. 1. 4 is a block diagram showing the heavy metal ion purification section in the refining section of FIG. 1. FIG. 5 and FIG. 6 are block diagrams showing a part of the control section of FIG. Flowchart showing the operation of the processing unit y) of the salt refining section. Figures 88 (A) and (B) are flowcharts showing the operation of the processing unit of the fourth ion purification section. '1 Material solution production department 1 3...Dye supply section, 5...Dye powder, 7...Dye valve, 8...Blending tank, 11...Pure valve. 13...Pure water supply? i↑, 15...Blending tank stirrer, 17...Blending tank liquid level detector. 19...filtration filter, 21...supply tank, 23...supply pipe. Precision, °, ″, 100 10OA 100B) 100
^...Inorganic salts purification section 10! ...Salt reduction tank. 103... Salt reduction filter, 105... Salt removal tank, 107... Supply valve, 109... Salt reduction tank stirrer, 111... Inorganic salt C degree detector, 113... Dye concentration Detector. 115...vA ring pump, 117...pure water valve, 121...storage valve, 100B...heavy metal ion purification section. ttit... Supply tank, +133... Supply tank liquid level detector, 165... Processing unit, 167... Supply valve, 1B11... Ion exchange resin column, +71... Valve, 173... - Heavy metal ion concentration detector, 175... Solution detector, 177... First discharge valve, +79... Storage tank, 181... Second discharge valve. 183...Circulation pump. Control unit 300 301...Controller, 302...Read only memory, 303...Random access memory, 304.305
... A/D converter, 308... Input 8727 circuit, 307-311... Drive circuit, 312... Output buffer 7 circuit, 313... Comparison section. 321... Dye concentration range 1 role switch, 322...
- Inorganic salt concentration range setting switch, 323... Input/output buffer circuit, 324... Dye concentration display. 325... Inorganic salts concentration indicator, 331... Input eight circuit, 332.333... Drive circuit. 3:34...Output buffer circuit. 3;35...Switch. 336...Input/output 4727 circuit, 337...Display device. 338...Drive circuit, 341...A/D converter, 342...Manipulator circuit, 343', 344.345...Drive circuit, 34
I3...Output 4777 circuit. Patent applicant Canon Co., Ltd. Figure 1 311

Claims (1)

[Scope of Claims] A method for producing a dye solution, and a method for removing inorganic salts from the dye solution by membrane separation.
A dye purification apparatus comprising: a solution treatment means; and a second solution treatment means for trapping heavy metal ions in the dye solution by performing r-on exchange separation. (Margin below)