JPS59182861A - Apparatus for purification of dye - Google Patents

Abstract

PURPOSE:To enable the continuous production of purified dye suitable for the ink of writing utensils, by using a means for preparation of a dye solution in combination with a means for detecting the concentration of inorganic salt in said solution. CONSTITUTION:Dye powder 22 is fed from the dye reservoir 21 to the mixing tank 24, and the prepared dye solution is supplied through the feeding tank 31 to the purification zone 41 furnished with a detector 46 to detect the concentration of inorganic salts by ion chromatography, etc. When the concentration of the inorganic salt detected by the detector 46 is higher than a preset level (preferably <=5wt%), the solution is passed through a salt-rejection filter 43 to separate the inorganic salt and obtain purified dye.

Description

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

[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 can be 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 glycols as a drying inhibitor.

Here, the water-soluble dye 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.

If recording ink is prepared using dyes containing such inorganic salts, the following disadvantages will arise in East Germany. That is,
Inorganic salts reduce the stability of dye dissolution in the ink, leading to solidification and precipitation of dye 4. In addition, in inkjet recording bends and writing instruments, when the ink changes near the ejection orifice and the liquid composition changes, it causes the precipitation of inorganic salts. 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 concentration of inorganic salts within a predetermined range (for -n9, 0.5% by weight or less in the ink) during ink production. This means that general commercially available dyes containing inorganic salts as impurities can be
i1. Tea is essential when used in the preparation of ink for marking instruments.

[1-1-1] In view of the above points, the object of the present invention is to control the '11IL organic salts contained in the ink when preparing the ink, thereby improving the quality of the ink-side recording ink. Yay (-
It is an object of the present invention to provide a dye manufacturing device capable of continuously supplying a purified dye solution suitable for preparing ink for marking instruments, etc.

[Example] The present invention will now be described in detail with reference to the drawings.

FIG. 1 shows an embodiment 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. Furthermore, pure water is supplied to the blended stem 124 through a pure water supply pipe 26 into which a pure water valve 25 is inserted.

In this mixing tank 24, the supplied dye powder 22 and pure water are combined and dissolved by a mixing tank agitator 27 to produce an aqueous dye solution. Preparation 4 (The amount of the dye aqueous solution stored in the Ili 24 is detected by the preparation tank liquid amount detector 28.
There are residual particles such as dye powder that did not dissolve in the pure water, and these are removed by the filtration filter 28. For this filter 28, ordinary filter paper or Fluorobor (trade name) or the like may be used. The aqueous dye solution that has been passed through six filters 28 to remove particles and the like is supplied to the supply tank 31.

The aqueous dye solution supplied to the supply tank 31 is
2 is stored in the supply tank 31 as long as it is in the closed state. Here, this supply +! I31 has a valve 3 for controlling the liquid level.
3, and dye aqueous solution I (k of -) stored in the supply tank.
Keep it below -・planting.

Next, 41 is a purification f that excludes inorganic salts from the dye aqueous solution.
H! It is. In this purification section 4H, 42 is a salt reduction tank;
43 is a salt reduction filter, and 44 is a salt removal tank. 1J
An aqueous dye solution is supplied to the ili jl and X tank 42 via the supply valve 32. This supplied aqueous dye solution is
The aqueous solution is homogenized by stirring in the salt reduction tank 42 45, and the inorganic salt concentration in the aqueous solution is detected by the inorganic salt concentration detector 46. This concentration detection is performed, for example, by ion chromatography. Further, the dye production in the aqueous solution is detected by the dye production level detector 47.

This concentration detection is performed, for example, by spectrophotometry. As described later, when the concentration of inorganic salts is set to a predetermined value (for example,
When it is detected that the dye is less than 5 tons (3%) or less, the circulation pump 48 is activated to circulate the dye aqueous solution in the salt reduction tank through the salt reduction filter 43. . This I salt reduction filter is, for example, an ultrafiltration filter.

Use a reverse osmosis filter, etc. By passing through the salt-reducing filter 43, inorganic salts such as sodium chloride and sodium sulfate contained in the dye aqueous solution are filtered from the dye aqueous solution as an aqueous solution and discharged into the waste tank 44.

In this way, a portion of the water, which is a solvent for the dye, is discharged into the salt tank 44 together with the inorganic salts. Then, the dye aqueous solution is replenished with this discharged water, and pure water is supplied to the salt-reducing tank 42 via the pure water valve 49 so that a dye aqueous solution of the desired concentration can be obtained in the salt-reducing tank 42. supply

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 42. Note that the amount of dye aqueous solution in the salt reduction tank 42 is detected by a salt reduction tank liquid amount detector 50.

vI after purification (g salt) as described above! #: Discharge the feed water to the storage tank 52 via the storage valve 51 and store it in the storage tank.

FIG. 2 shows the control system of the apparatus shown in FIG. Here, 6
Reference numeral 1 denotes a controller, which controls the drive of each part. 62
It is a single-only memory (:ROM).

A control program such as the operating procedure shown in FIG. 3 is written t0. Reference numeral 63 is a random access memory (RAM) in which temporary memory ttJ of each JΦcheetah, etc. is made.

In this example, the inorganic salt concentration detector 46 and the dye concentration detector 47 output analog k<, and A
/'Digital (ifl) via D converters 64 and 65
After being converted into 4, it is supplied to the controller 61 via the input 8227 circuit 66.
A digital signal is output from the low-salt tank 28 and the low-salt tank 1 night supply detector 50, respectively, and is supplied to the controller 61 via the input signal filter circuit 66.

67 to 74 are +iii mentioned valves 23, 25, 49
, 32 , U-Yohi 51 , stirrers 27 and 45 , and I-live circuits for driving the circulation pump 48 , respectively, and the drive is supplied from the controller 61 via the output H2F circuit 75 . Controlled on/off by signal.

81 and 82 are a dye concentration range setting swifter and an inorganic salt concentration range setting swifter, respectively.
J: A signal corresponding to the defined concentration range is supplied to the controller via the console input/output circuit 83. 84
and 85 are the dye concentration indicator and 11 (
This is a type A concentration display, which displays the dye concentration value and inorganic salt concentration value in the dye aqueous solution being purified. Therefore, the operator of this equipment is responsible for dye-soluble water during production! The quality of the night can be easily determined.

The values set for the dye concentration range and inorganic salt concentration range by switches 815 and 82 are temporarily stored in RAM G3. Inorganic salt concentration detector 46 and dye concentration detector 47
The detection concentration values of inorganic salts and dyes in the aqueous dye solution being purified are compared with the set values in the ratio 1 section 611 of the controller, and based on the comparison results, the circulation pump is adjusted as described below. The driving of each load such as 48 is controlled.

FIG. 3 shows the operation flow of the apparatus shown in FIG. In the figure, steps STI to ST4 are steps for maintaining the dye aqueous solution in the mixing tank 24 at a constant amount. That is, in step STI, it is determined from the output of the mixing tank liquid level detector 28 whether or not the liquid level of the dye aqueous solution in the mixing tank 24 is at a level with respect to the lower level 1d that defines a predetermined setting range. To detect. If the city is F higher than the lower one city, the process proceeds to step ST2; otherwise, the process proceeds to step ST3. In step ST2, the dye valve 23 and pure water valve 25 are opened, and predetermined amounts of dye powder and pure water are respectively introduced into the mixing tank 28.

In the mixing tank 24, since the stirrer 27 is always in operation, the dye powder introduced is dissolved in pure water and an aqueous dye solution is prepared. In step ST3, the liquid record detector 28
Based on the output, it is detected whether the liquid level in the mixing tank 24 is above the high position that defines the setting range. If the position is higher than the higher position, the process proceeds to step ST4, and if not, the process proceeds to step ST5. In step ST4, the dye valve 23 and pure water valve 25, which are in the open state, are closed to stop the supply of dye 1 powder and pure water.

In step ST5, f precept i1! detected by the dye concentration detector 47! The dye concentration value in the aqueous dye solution in the tank 42 is displayed on the display device 84. Step ST6 is the same (move 1).
In ST7, it is determined whether the dye concentration detected by the detector 47 is within the range of the dye concentration set by the switch 81. If it is determined that it is within the set range. If not, proceed to step ST8. In step ST8, the concentration of inorganic salts detected by the detector 46 is detected by the switch 8.
2, it is determined whether the value is within the range of values set. If it is determined that it is within the setting range, step 5T
Proceed to IO, and if not, proceed to step ST9.

In step ST9, the salt-reducing tank 4 detected by the detector 5o
It is determined whether the liquid level in 2 is above the 1, 7J position that defines the installation range. If it is below that high position, proceed to step 5TII, otherwise proceed to step 5T12. In step 5TII, the supply valve 32 and the pure water valve 48 are controlled to open and close to supply 4 volumes of Somemura water and pure water into the salt reduction tank 42. With this, the pirate 114 + 1'
The dye JI strength in the dye aqueous solution in V 42 is 1-
Just like V, the swift 81 adjusts the numbers so that they fall within the range of 1. After this, proceed to step 1, step 5TI3. - In step 5T12, the supply valve 32 and the pure water valve 49 are closed.

In Step 5TI3, the circulation pump 48 is operated to circulate the dye aqueous solution in the salt bath 42 through the g salt filter 43 to remove inorganic salts from the dye aqueous solution.

As mentioned above, if the dye concentration and inorganic salt concentration are outside the 1-death range, repeat the routine through Hand+1ff4 ST l l and Step 5T13 or Step 5TI2 and Step 5T13 to adjust the dye concentration and inorganic salt concentration. The value shall be within the setting range. After the image density falls within the set range, proceed to step 5TIO.

In step 5TIO, it is determined whether the liquid level in the salt reduction tank 42 detected by the detector 50 is 1-1 lower than the low position that defines the setting range. than that lower position”- in the case of
Proceed to step 5T14, otherwise 'f-ship 5T
15, in fU0 procedure STI, the operation of the circulation pump 48 is stopped and the storage valve 51 is opened. As a result, a predetermined amount of the purified dye aqueous solution rubbed in the salt reduction tank 42 is supplied to the storage tank 52.

In the hand++11iST15, the closing operation of the storage valve 51 and the supply valve 32. Perform the opening operation of the pure water valve 49,
At the same time as the supply to the storage tank 52 is stopped, the amount of the dye aqueous solution in the salt reduction tank 42 is increased so that the thickness of the dye solution is within the set range.

After this, the above-mentioned hand 111FiST11,5T13
Or ``By repeating the routine passing through steps 5T12 and 5T13, a predetermined amount of dye aqueous solution whose dye concentration and inorganic substance concentration are within the specified range is obtained in the tank 42. , proceed to step 5TI4 described above.

As described above, in this embodiment, the dye aqueous solution is purified for each specific product in the purification section 41.

Effect] As explained above, according to the present invention, the concentration of inorganic salts contained in the dye solution is detected when producing the dye solution, so that it is possible to detect the concentration of inorganic salts contained in the dye solution. It is preferred for producing purified dye solutions suitable for preparing inks and the like.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing one embodiment of the device δ according to the present invention, FIG. 2 is a block diagram showing the control section of the device shown in FIG. 1, and FIG. 3 is a diagram showing the operation of the device shown in FIG. 1. This is a flowchart 1 shown in FIG. 21... Dye supply unit, 22... Dye powder, 23... Dye valve, 24... Mixing tank, 25... Pure water valve, 2... Pure water supply pipe, 27... Preparation tank stirrer 28... Preparation tank liquid level detector, 28... Filtration filter, 3... Supply tank, 32... Supply Harz, 33... Masu, 41... Purification section, 42 ... Salt reduction tank, 43 ... Makoto filter, 44 ... Salt removal tank, 45 ... Salt reduction tank agitator. 48...Inorganic salt concentration detector, 47...Dye concentration detector, 48...Circulation pump, 49...Pure water valve, 50...Salt reduction tank liquid level detector, 51... Storage valve, 52...Storage tank, 61...Controller, 62...Read only memory (ROM), 63...
Random access memory (RA1'l), 64.85.
...A/D converter. 66...4777 human power circuits, 67-74...7 dry circuits, 75...output power circuit, 81...dye JI? i degree range setting switch. 82... Inorganic salt concentration range setting cavities inch, 83...
・Console input/output huff circuit. 84... Dye concentration indicator, 85... Inorganic salt concentration indicator, 81]... Comparison section.

Claims (1)

[Claims] 1. A dye purification device comprising: means for producing a dye solution; and means for detecting the concentration of inorganic salts in the solution.