JPH07290066A - Separation of ingredient of water-soluble coating - Google Patents

Abstract

PURPOSE:To inexpensively and easily remove and abandon a waste water-soluble coating by rapidly and sufficiently separating a water-soluble coating ingredient from a liq. contg. a water-soluble coating produced in the coating booth, coating activity, etc., with a simple device. CONSTITUTION:A pulsating wave of 24V is impressed with a metallic water tank 1 in a coating booth as the positive electrode and an electrode plate 2 provided in the tank 1 as the negative electrode to cause electrolysis, hence bubbles are produced from around the electrode plate 2, the water-soluble coating ingredient is floated along with the bubbles, the floated bubbles are subjected to natural sedimentation, and the water-soluble coating is removed as the sediment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention separates a water-soluble paint component from a liquid mixed with the water-soluble paint generated in a painting work using the water-soluble paint, a water-soluble paint peeling work, etc. The present invention relates to a technique that facilitates treatment and removal of water-soluble paint.

[0002]

2. Description of the Related Art Conventionally, there is a method of capturing a paint component with a filter by passing a liquid containing a water-soluble paint through an ultrafine filter of about 8 microns. In this case, there is a problem that clogging occurs in a short time, the filter cannot be used, the filter needs to be replaced frequently, and the work is troublesome and the cost is high. As an alternative method, there is also known a method in which a tack-free agent is added to a liquid containing a water-soluble paint, the paint components are floated and separated, and the floated paint components are removed. However, in this method, a large amount of water-soluble paint components that do not float up remain in the form of fine particles that float in water, and it is not possible to sufficiently separate and remove the paint components. Furthermore, a method of adding a chemical to perform precipitation separation is also known, but this requires a continuous use of the chemical, which increases running cost and is troublesome because it is necessary to adjust the amount of the chemical input. There is.

[0003]

The problem to be solved by the present invention is to solve these problems of the prior art, to sufficiently separate the water-soluble paint components with a simple device, and to make removal and disposal inexpensive and easy. Another object of the present invention is to provide a method for separating coating material components of a water-soluble coating material.

[0004]

Means for Solving the Problems The constitution of the present invention which has solved the above problems is as follows: 1) An electrode member is provided in the vicinity of a liquid mixed with a water-soluble coating material, and a pulsating wave or DC voltage is applied to the electrode member. Is applied,
Separation of water-soluble paint components by precipitating water-soluble paint components by electrolysis 2) Method for separating paint components of water-soluble paint 2) Mixing a tack-free agent in a liquid mixed with water-soluble paint, An electrode member is provided close to the liquid, a pulsating wave or a DC voltage is applied to the electrode member, the water-soluble paint component is electrolyzed to rise in a foam state, and the rising foam is collected to paint. Method for separating paint components of water-soluble paint characterized by separating components 3) Mixing a tack-free agent in a liquid mixed with water-soluble paint, and providing an electrode member in the vicinity of the liquid to form the same electrode A pulsating wave or direct current voltage is applied to the member to raise the water-soluble paint component in a foam state by electrolysis, and an antifoaming agent is added to this to defoam to precipitate the water-soluble component and remove the paint component. Method for separating paint components of water-soluble paint characterized by separating ) Is in the 3) paint component separation method of the water-soluble paint according to precipitate water soluble coating component and mixes the liquid and foam at the same time on and defoamers.

The voltage applied in the present invention is practically several V to several hundred V, and preferably 10 to 60 V. The tack-free agent of the present invention is an agent that loses the adhesive force of the water-soluble paint to the surface of an object, and examples thereof include cationic polymer Hakutron S-800, sodium zincate, and Hakfloc F which is NaOH. -750 (both are trade names, Hakuto Co., Ltd.) is a two-part chemical that uses two liquids, coating booth cleaner PBW4500 (trade name, Million Chemical Co., Ltd.) and the like. Further, the antifoaming agent of the present invention is a chemical agent that binds to a foam substance existing on the liquid surface and in the liquid and causes it to settle. ), Fomclean W-650 (trade name, Hakuto Co., Ltd.) and the like. If necessary, a pH adjusting agent may be added to this. The distance between the electrode members is preferably several millimeters to several tens of millimeters. The water-soluble paint of the present invention also includes emulsion-type water-soluble paint.

[0006]

In the present invention, the electrode member is disposed in close proximity to the liquid containing the water-soluble paint, and a pulsating current or a direct current voltage is applied to this to promote ionization of water and the water-soluble paint, and Hydrogen gas is generated, and the paint components rise with the gas. This paint component largely rises like a bubble from the surface of the liquid and floats up. Bubbles are generated within a few seconds after the voltage application is started, and the water-soluble paint component is raised as bubbles within about several tens of minutes. The bubbles disappear little by little over time, and the water-soluble paint components precipitate. Alternatively, scrape or collect the bubbles by suction. This allows the water soluble paint components to be collected in the form of foam. The collected bubbles disappear over time, leaving only the water-soluble paint. It can be easily disposed of by incineration. In addition, it is possible to rapidly precipitate in the liquid by generating bubbles and adding an antifoaming agent. Let it settle on the bottom of the liquid,
A predetermined amount of precipitation can be obtained, and the water-soluble paint component can be collected as a precipitate by mechanically sucking from the liquid tank / liquid path or from the bottom.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. 1 is an explanatory view showing a first embodiment of the present invention, FIG. 2 is an explanatory view showing a second embodiment of the present invention, and FIG. 3 is a third embodiment of the present invention.
And FIG. 4 is a cross-sectional explanatory view showing the third embodiment.

Example 1 (see FIGS. 1, 5 and 6) In Example 1 shown in FIG. 1, a coating waste liquid containing a large amount of overspray paint paint generated in the coating work of a coating booth is stored in a water tank, and The water-soluble paint is electrolyzed to generate bubbles, and then the power is turned off to cause natural precipitation, which is discharged from the bottom of the water tank and filtered with a paper bag, and then the filtered water is returned to the painting booth for reuse. In this example, the paint is collected in a paper bag and easily disposed of by incineration. In Figure 1,
1 is a metal water tank for storing a coating booth liquid containing a water-soluble paint, 2 is an electrode plate for a negative electrode, 3 is a liquid introducing pipe for a coating booth containing a water-soluble paint, 4 is a self-priming pump, 5 Is a suction port strainer, 6 is a water tank in which a water-soluble paint in a coating booth is mixed, 7 is an air blow pipe, 8 is an air blow fan, and 9
Is a voltage generator, 10 is a drain pipe, 11 is a filter paper bag, 12 is a filtered water return pipe, and 13 is a clean water drain pipe for returning to the coating booth.

In the first embodiment, the liquid containing the water-soluble paint in the water tank 6 in the coating booth is sucked by the self-priming pump 4 to the metal water tank 1 via the suction strainer 5 and the introducing pipe 3. Be transferred. A negative electrode is connected to the electrode plate 2 of the water tank 1 and a positive electrode is connected to the water tank 1 itself, and a relatively low DC or pulsating wave voltage is applied by the voltage generator 9.
Then, the liquid in the water tank 1 is electrolyzed, a large number of gas bubbles are generated in the electrode plate 2, and the bubbles rise. Also, the liquid becomes cloudy due to bubbles. Bubbles are generated for several tens of minutes, and then the power is turned off
Then, the liquid from the air blow pipe 7 is agitated,
When the stirring is stopped, the water-soluble paint settles on the bottom surface of the water tank 1. When the voltage and its waveform in the liquid of the water-soluble paint of melamine resin having a concentration of 3% are changed, the voltage application time at which the generation of bubbles does not occur is approximately as follows. 24V Approximately 30 minutes for the voltage waveform of FIG. 24 Approximately 40 minutes for the voltage waveform of FIG. 6 Approximately 40 minutes for the 24V DC 74 minutes 46V Approximately 20 minutes for the voltage waveform of FIG. 6 Then, after stopping the energization, the air blow tube 7 Blow in air from and stir for a few minutes. After stirring, the generation of bubbles almost disappeared and the solution was settled in about 30 minutes to several hours (the settling time changes depending on the paint concentration), the liquid in the water tank 6 becomes transparent, and the paint color disappears. After sufficient precipitation, the drain pipe 10 is opened and the precipitate and the liquid are sent into the filter paper bag 11 from the bottom surface in the water tank 6. The precipitate is collected by the paper bag 11. On the other hand, the water that has passed through the paper bag 11 is reused as water used for the coating booth. The water-soluble paint collected in the paper bag 11 can be incinerated after being dried together with the paper bag 11. As a result, the water-soluble paint components can be separated and removed / discarded economically in a short time by using a simple electrode and power supply device and a paper bag.

In the second embodiment shown in FIG. 2, Hakutron S-800 and Hakufloc F-75 are installed in a water tank of a wet coating booth.
0 (Trade name, Hakuto Co., Ltd.) non-adhesive to Hakutron S-800 5-8 against the amount of overspray paint
% And Hakufloc F-750 at a ratio of 20 to 64% to float the water-soluble paint component in the form of foam, suction the surface layer with a suction pump, filter with a paper bag, and filter the water-soluble paint component into a paper bag. This is an example of collecting. In FIG. 2, 20 is a water tank containing water-soluble paint, 21 is a wet coating booth, 22 and 23 are electrode plates, 24 is a trough for collecting bubbles on the liquid surface layer, 25 is a self-priming pump, and 26 is discharge of bubbles. Tube, 27 is a floating foam liquid free fall tank, 2
Reference numeral 8 is a filter paper bag, and 29 is a reflux pipe for purified water that has passed through the paper bag.

In Example 2, Hakutron S-800 and Hakufloc F-750 were used as a tack-free agent in a ratio of 1: 4-8.
Then, a pulsating current or a DC voltage is applied to the electrode plates 22 and 23. This causes electrolysis and strongly raises the water-soluble paint as a foam. The self-priming pump 25 sucks the bubbles rising to the liquid surface into the gutter 24, sends the bubbles to the filter paper bag 28 through the floating bubble liquid natural fall tank 27, and the paper bag 28 captures the water-soluble paint in the foam. To gather.
Then, the purified water that has passed through the paper bag 28 is returned to the water tank 20 again via the reflux pipe 29. In this case, when a direct current of 15 V was applied to a 3% liquid solution of a melanin resin water-soluble paint, a large number of bubbles were generated on the liquid surface immediately after the application, the power supply was stopped in 3 minutes, and left as it was for 11 hours. Then, it precipitates. Therefore, after 3 minutes, the self-priming pump 2 is pumped at a time of several minutes to several tens of minutes when bubbles are generated so as to rise largely on the liquid surface.
Activate 5 to collect almost all the bubbles. This increases the transparency of the liquid in the water tank 20.

In the embodiment shown in FIGS. 3 and 4, Hakutron S-800 and Hakufloc F-7 are applied to a liquid containing a water-soluble paint.
50 was charged with a non-adhesive agent in a ratio of 1: 4 to 8 to cause foaming, and the foam was overflowed above and moved to the next water tank, and Fomclean W-650 was used as a defoaming agent.
Is added to defoam, and the paint components are precipitated, discharged from the drain drain on the bottom of the water tank and collected in a paper bag. Further, the bubbles are collected from the upper surface of the water tank at the final stage and then sent to a paper bag to collect the paint component in the paper bag. The water that has passed through the paper bag is returned to the painting booth for reuse. 3, 31, 32 in FIGS.
Is a metal separation tank for storing a liquid containing a water-soluble paint and performing a separation treatment, 33 is a filter paper bag, 34 is a negative electrode plate, 35 is a transformer for applying a DC voltage, and 36 is a floating bubble sludge free fall tank 37 is a drain pipe from the bottom of the separation tanks 30, 31 and 32, 39 is a filter paper bag, 40 and 41 are filtered water return pipes to the coating booth, and 42 is the introduction of the water-soluble coating liquid from the water tank of the coating booth. A pipe, 43 is a strainer, and 44 is a self-priming pump.

In this embodiment, the liquid containing the water-soluble paint in the water tank of the coating booth is introduced into the introduction pipe 41, the strainer 42,
It is sent to the first-stage separation tank 30 via the self-priming pump 43. Here, a negative electrode is fed to the negative electrode plate 34, a positive electrode is fed to the main body of the separation tank 30, and a DC voltage of the transformer 35 is fed. Then, when Hakutron S-800 and Hakufloc F-750 as detackifying agents are put into the separation tank, they are foamed by electrolysis to raise the insoluble coating composition. When the bubbles rise, the defoaming agent of Fomclean W-650 is added and if necessary agitated, many bubbles are defoamed and the water-soluble paint is deposited on the bottom surface of the separation tank. The bubbles that float and do not defoam continue to overflow into the second and third separation tanks 31 and 32, and finally flow into the floating foam sludge natural dropping tank 36, are sent to the filter paper bag 39, are filtered, and are dissolved in water. The sex paint is collected in the paper bag 39. The water that has passed through the paper bag 39 is reused as water for the coating booth through the filtered water return pipe 41. Further, the sediment is periodically discharged from the drain pipe and simultaneously sent to the filter paper bag, the sediment is collected, and the water passing through the paper bag is returned to the coating booth by the filtration reflux pipe 41 and reused. Examples 2 and 3
It is generally possible to process the voltage in a short time by applying a pulsating current voltage rather than a direct current. The higher the voltage, the faster the processing.

[0014]

As described above, according to the present invention, a water-soluble paint is prepared by simply providing an electrode in a liquid mixed with a water-soluble paint and applying a relatively low voltage to the electrode to cause electrolysis. It can be easily separated by allowing the components to settle within a few hours or by collecting the floating foam. If a tackifier is added to this, it is possible to promote the rise in the form of foam and quickly collect the insoluble paint component as foam. In addition, add defoaming agent and stir.
It is also possible to stop and settle to recover the insoluble paint.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a first embodiment of the present invention.

FIG. 2 is an explanatory diagram showing a second embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a third embodiment of the present invention.

FIG. 4 is a cross-sectional explanatory view showing a third embodiment.

FIG. 5 is an explanatory diagram showing a waveform of a voltage applied in the first embodiment.

FIG. 6 is an explanatory diagram showing a waveform of a voltage applied in the first embodiment.

[Explanation of symbols]

 1 Metal Water Tank 2 Electrode Plate 3 Introducing Tube 4 Self-Priming Pump 5 Suction Strainer 6 Water Tank 7 Air Blow Pipe 8 Air Blow Fan 9 Voltage Generator 10 Drain Pipe 11 Filter Paper Bag 12 Filtered Water Reflux Pipe 13 Clean Water Drain Pipe 20 Water Tank 21 Wet Coating Booth 22 Electrode Plate 23 Electrode Plate 24 Gutter 25 Self-Priming Pump 26 Foam Liquid Discharge Pipe 27 Floating Foam Liquid Natural Fall Tank 28 Filter Paper Bag 29 Reflux Pipe 30 Separation Tank 31 Separation Tank 32 Separation Tank 33 For Filtering Paper bag 34 Negative electrode plate 35 Transformer 36 Floating foam sludge free fall tank 37 Drain pipe 38 Missing number 39 Filter paper bag 40 Filtered water return pipe 41 Filtered water return pipe 42 Inlet pipe 43 Strainer 44 Self-priming pump

Claims (4)

[Claims] 1. An electrode member is provided in the vicinity of a liquid in which a water-soluble paint is mixed, a pulsating wave or a direct current voltage is applied to the electrode member, and the water-soluble paint component is precipitated by electrolysis to be water-soluble. A method for separating paint components of a water-soluble paint, which comprises separating paint components. 2. A water-soluble paint is mixed with a non-tackifying agent in a liquid, an electrode member is provided in the liquid in the vicinity thereof, and a pulsating wave or a direct current voltage is applied to the electrode member to dissolve the water-soluble paint. A method for separating a paint component of a water-soluble paint, which comprises raising a water-soluble paint component in a foam state by electrolysis and collecting the rising foam to separate the paint component. 3. A water-soluble paint is mixed with a non-adhesive agent in a liquid, an electrode member is provided in the vicinity of the liquid, and a pulsating wave or a DC voltage is applied to the electrode member to dissolve the water-soluble paint. Separation of paint components of water-soluble paint, characterized in that the water-soluble paint components are raised in a foam state by electrolysis, and a defoaming agent is added to this to defoam to precipitate water-soluble components and separate paint components. Method. 4. The method for separating paint components of a water-soluble paint according to claim 3, wherein the liquid and the foam are stirred at the same time as the introduction of the defoaming agent to precipitate the water-soluble paint components.