JP2002102788A - Method and device for treatment before coating - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a device for a treatment before coating by which refuse is minimized by recycling a chemical conversion liquid as washing waster and the chemical conversion liquid in consideration of the capacity balance and the material balance of the chemical conversion liquid and by which circulating type closing of the whole of the device for treatment before coating is attained. SOLUTION: This method comprises at least a chemical conversion process for bringing the chemical conversion liquid housed in a chemical conversion tank 12 into contact with a matter to be treated to convert the matter chemically and a water washing process consisting of at least one stage for bringing the washing water housed in a washing water tank 13 into contact with the matter to wash the matter to be treated chemically with water. A part of the chemical conversion liquid housed in the tank 12 and a part of the washing water housed in the tank 13 are mixed to prepare a mixed liquid. The mixed liquid is subjected to dialysis treatment with a filter 21 to separate it into concentrated liquid and permeated liquid and to send the obtained concentrated liquid to the tank 12 and the obtained permeated liquid to the tank 13, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pretreatment method and a pretreatment apparatus for coating such as phosphoric acid conversion, which are widely used industrially for coating bases. The present invention relates to a coating pretreatment method and a coating pretreatment device that can be reused as a chemical treatment liquid and washing water without being discharged out of the system.

[0002]

2. Description of the Prior Art Phosphate treatment is generally performed as a pre-coating treatment for metal products such as electric products, automobile bodies, and automobile parts. The pretreatment step by phosphate treatment is generally a degreasing step, a degreasing and washing step,
It comprises a surface conditioning step, a chemical conversion step, a post-chemical washing step, and a drying step. The degreasing step and the two washing steps often include two or more steps. For example,
As typical automobile body lines, the following pretreatment steps are exemplified (the last “step” is omitted in each step). 1st degreasing → 2nd degreasing → 1st washing → 2nd washing → surface adjustment →
Phosphate conversion treatment → 3rd washing → 4th washing → 5th washing → deionized washing → drying

At this time, generally, in each washing step,
The overflow water is fed to the first stage from the second washing to the first washing and from the deionized washing to the fifth washing. Further, industrial water is supplied in the fifth rinsing, and the overflow water is fed to the first stage from the fifth rinsing to the fourth rinsing and further to the third rinsing.

[0004] The overflow water in the rinsing step (the first rinsing step and the third rinsing step) immediately after the degreasing step and the chemical conversion step, respectively, must be discharged after the wastewater treatment outside the system. However, from the viewpoints of environmental conservation and effective use of resources, it is desired to effectively use these washing waters, and to provide a closed system that does not discharge these washing waters out of the system at all. In particular, it is difficult to make an efficient closed system for the washing water after the chemical conversion treatment.

[0005]

As a conventional closed system which effectively uses the above-mentioned washing water, (1)
Examples of the method and apparatus include an in-system evaporation method, (2) an out-of-system evaporation method, (3) a vacuum distillation method, and (4) a wastewater treatment + reverse osmosis membrane method.

(1) The in-system evaporation method promotes the evaporation of water in the pretreatment step by temperature, spray and exhaust air volume, keeps the balance between the amount of evaporation and the amount of supplied water (amount of discharged water), and constantly discharges water outside the system. There is no method. However, the in-system evaporation method is effective when the chemical conversion treatment liquid temperature is high,
At present, the temperature of the chemical conversion treatment has been reduced, and in order to adopt this method, the exhaust air volume must be increased, which is inefficient. The generated steam contains chemical conversion components such as heavy metals, phosphorus, and nitrogen components. It is environmentally unfavorable to release these components into the atmosphere and, at the same time, corrodes the apparatus.

(2) The out-of-system evaporation method is a method in which the discharged washing water is evaporated using a concentrator and an exhaust fan. However, since the chemical conversion solution is acidic, nitrogen components are mixed in the exhaust gas, and disposal of the concentrated solution is also a problem. There is also a method in which the chemical conversion treatment liquid is neutralized and then evaporated, but the reuse of water is not considered. In addition, this method requires a large amount of energy, and is not preferable from the viewpoint of resource saving and environmental protection.

(3) The vacuum distillation method is a method in which wastewater is distilled under reduced pressure and water is reused as washing water by cooling and coagulating in a condenser. However, when the amount of wastewater is large, the vacuum distillation apparatus must be enlarged, and the wastewater is slightly acidic due to nitrogen components.
The distilled retentate must be discarded.

(4) Wastewater treatment + reverse osmosis membrane system aims to reuse washing water with a reverse osmosis membrane. The wastewater is treated with a reverse osmosis membrane after coagulation sedimentation, sand filtration and activated carbon treatment. In this method, water is reused as washing water. However, although the reused water is almost pure water, the concentrated liquid must be discarded. Therefore, a wastewater treatment device must be added, and the size of the device is increased.

[0010] All of the above methods are performed for the purpose of evaporating and discharging the washing water or reusing it as washing water, and the chemical conversion liquid components contained in the washing water are not collected but discarded. . In the above-mentioned (2) out-of-system evaporation method, (3) vacuum distillation method, and (4) wastewater treatment + reverse osmosis membrane method, when the concentrated liquid of washing water is returned to the chemical treatment liquid, unnecessary components accumulate, and Therefore, it is impossible to reuse the concentrated liquid.

Here, the reaction formula of the chemical conversion treatment with zinc phosphate applied to the pretreatment process of the automobile body and the like is represented by the following formula (1).
Shown in (1) 3Zn (H ₂ PO ₄ ) ₂ → 4H ₃ PO ₄ + Zn ₃ (P
O ₄ ) _{2 In} order to make this reaction proceed, the object to be processed, for example, a steel part is etched with phosphoric acid as shown in the formula (2). (2) Fe + 2H ₃ PO ₄ → Fe (H ₂ PO ₄ ) ₂ + H ₂

In order to remove the etched iron, sodium nitrite (NaNO ₂ ) is used as an oxidation promoter.
An aqueous solution is always added. When NaNO ₂ is added to the chemical conversion treatment solution under acidic conditions, it becomes HNO ₂ , and the reaction represented by the following formula (3) occurs. (3) Fe (H ₂ PO ₄ ) ₂ + HNO ₂ → FePO ₄ + N
O + H ₃ PO ₄ + H ₂ O

However, HNO ₂ is converted into nitric acid (ion) by air oxidation as shown in equation (4), or
As shown in (1), it reacts with Fe to form ammonium ions. (4) HNO ₂ + O → HNO ₃ (5) 3Fe + HNO ₂ + 7H ₃ PO ₄ → 3Fe (H ₂ P
O ₄ ) ₂ + NH ₄ H ₂ PO ₄ + 2H ₂ O

Further, sodium ions are generated from sodium nitrite and are accumulated in the chemical conversion treatment solution. As described above, nitrate ions (NO ₃ ), ammonium ions (NH ₄ ⁺ ), sodium ions (N
a ⁺ ) etc. are accumulated. These components are components that are originally unnecessary as chemical conversion treatment solution components, or components that do not require an appropriate amount or more when accumulated (these components are hereinafter referred to as “unnecessary accumulation components”). .
It is difficult to reuse the washing water as a chemical conversion treatment liquid simply by concentrating the washing water without removing unnecessary accumulated components.
In order to solve this problem, nitrate ion,
It becomes necessary to remove unnecessary accumulation components such as ammonium ions and sodium ions.

As a method of concentrating the washing water and reusing it as a chemical conversion treatment liquid, a nanofilter membrane, a reverse osmosis membrane (RO)
Membrane) or a method using a pressure dialysis membrane. The nanofilter membrane, reverse osmosis membrane, and pressure dialysis membrane have the effect of removing a part (particularly, unnecessary accumulated components) of the chemical treatment solution component, so that the concentrated solution of washing water can be returned to the chemical treatment solution. is there.

However, in the chemical conversion treatment liquid, the carry-in of the liquid (for example, the surface conditioning liquid) in the previous step by the work (object to be treated) and the carry-out of the chemical conversion treatment liquid by the work are balanced at a fixed volume. When an energy-saving (low-temperature type) chemical treatment chemical is used, evaporation of the chemical treatment solution can hardly be calculated, and a concentrated solution (rinse water concentrate) obtained using a nanofilter membrane or a pressure dialysis membrane is formed. When used as a treatment liquid, the amount of the chemical treatment liquid increases by that amount, causing a problem that the chemical conversion treatment tank overflows. In order to solve this problem, it is necessary to evaporate the chemical conversion treatment liquid by an amount corresponding to the supplied washing water concentrate, which is not reasonable contrary to the demand for energy saving.

Therefore, in view of the above-mentioned circumstances, the present invention considers the volume balance and the material balance of the chemical conversion treatment solution, and not only reuses the washing water after the chemical conversion treatment, which was difficult to reuse, as the washing water, but also An object of the present invention is to provide a coating pre-treatment method and a coating pre-treatment device that can minimize waste by collecting and reusing chemical conversion liquid components. In addition, the present invention facilitates the recovery of the rinse water after the chemical conversion treatment, which was difficult to reuse, so that the coating pretreatment equipment (painting pretreatment line) can achieve a closed circulation system. An object of the present invention is to provide a pretreatment method and a painting pretreatment device.

[0018]

The above object is achieved by the present invention described below. That is, the coating pretreatment method of the present invention, at least, a chemical conversion treatment liquid contained in the chemical conversion treatment tank is brought into contact with the object to be treated, a chemical conversion treatment step of subjecting the object to a chemical conversion treatment, and contained in a washing tank And a washing step for washing the chemical conversion-treated object with water by contacting the rinse water with the object to be treated and one or more washing steps. A part of the treatment liquid, and a part of the washing water contained in the washing tank, are mixed to prepare a mixed liquid, and the mixed liquid is dialyzed with a filter to be separated into a concentrated liquid and a permeated liquid, The obtained concentrated solution is sent to the chemical conversion treatment tank, and the obtained permeate is sent to the washing tank.

In general, if the washing water after the chemical conversion treatment, which is generally waste liquid, is simply concentrated by a filter and is used as the chemical conversion treatment solution, the loss (mainly evaporation) of the chemical conversion treatment solution is reduced by the supplied washing water concentrate. And the chemical conversion treatment liquid overflows the chemical conversion treatment tank. Attempts to increase the concentration of the washing water concentrate to prevent this increase the load on the filter, which leads to an increase in the size and cost of the device, and also causes problems such as clogging. It also affects the reliability of the entire device including

However, according to the coating pretreatment method of the present invention, since the chemical conversion treatment liquid is also subjected to concentration by the filter together with the washing water after the chemical conversion treatment (the chemical conversion treatment liquid is reduced by this amount), it can be obtained. Even when the concentrated liquid is supplied to the chemical conversion treatment tank, the chemical conversion treatment liquid does not increase. In addition, instead of concentrating only the washing water after the chemical conversion treatment with a low concentration of the chemical conversion treatment component, the concentration is increased after mixing the chemical conversion treatment solution with a high concentration. The load can be reduced.

Therefore, according to the pre-coating treatment method of the present invention, not only the washing water after the chemical conversion treatment can be reused as the washing water, but also the components of the chemical conversion treatment solution can be collected and reused, The balance and material balance can be maintained appropriately. As a result, it is possible to minimize the waste generated in the pre-coating process. Further, since the washing water after the chemical conversion treatment, which has been difficult to reuse, can be easily collected, it is possible to achieve a closed circulation type of the entire coating pretreatment device (coating pretreatment line).

The effect of the present invention becomes more remarkable when the coating pretreatment method of the present invention is applied to an apparatus having multi-stage washing, which is common in various pretreatment lines for coating. That is,
The coating pretreatment method of the present invention when applied to an apparatus having multi-stage (n-stage) water washing includes the configuration of the above-described coating pretreatment method of the present invention, and the washing step is performed in n stages (n is an integer of 2 or more). ), And the rinsing in these rinsing steps is sequentially performed. Of these rinsing steps, the overflow water in the rinsing tanks of the second to nth rinsing steps is respectively transferred to the rinsing tanks of the preceding rinsing step. Then, the overflow water in the washing tank in the first washing step is used to prepare a mixed solution to be subjected to the dialysis treatment by the filter, and the filtrate obtained by the dialysis treatment is subjected to the first to nth washing steps. Wherein the liquid is sent to a washing tank in any one or more of the washing steps.

On the other hand, a coating pre-treatment apparatus of the present invention which can embody the coating pre-treatment method of the present invention is as follows:
And <2> the second mode. <1> At least a chemical conversion treatment means for causing a chemical conversion treatment liquid contained in a chemical conversion treatment tank to come into contact with an object to be treated to form a chemical conversion treatment on the object to be treated, and washing water contained in a washing tank to the object to be treated. A coating pretreatment device comprising at least one stage of water washing means for contacting with the liquid and subjecting the chemical conversion-treated object to water washing, and further comprising: converting a part of the chemical conversion treatment solution contained in the chemical conversion treatment tank. A chemical conversion treatment liquid supply pipe for supplying liquid, a washing water supply conduit for supplying a part of the washing water contained in the washing tank, and a chemical treatment treatment liquid supplied by the chemical treatment treatment liquid supply pipe And, a mixing means for preparing a mixed solution by mixing the washing water sent by the washing water sending pipe, and a filter for subjecting the mixed solution to dialysis treatment and separating into a concentrated solution and a permeated solution,
A concentrated solution sending pipe for sending the concentrated solution obtained by the filter to the chemical conversion treatment tank, and a permeated solution sending pipe for sending the permeated liquid obtained by the filter to the washing tank. A coating pretreatment apparatus characterized by the above-mentioned.

<2> At least a chemical conversion treatment means for causing the chemical conversion treatment liquid contained in the chemical conversion treatment tank to come into contact with the object to be treated to form a chemical conversion treatment on the object to be treated, and the washing water contained in the washing tank to be treated with the washing water. A coating pretreatment apparatus comprising: one or more stages of water washing means for contacting the treatment object with water and washing the chemical conversion-treated object with water; and The chemical conversion treatment liquid sending pipe for sending a part of the washing water, the washing water sending pipe for sending a part of the washing water contained in the washing tank, and the chemical conversion treatment solution sending pipe were sent. A chemical conversion treatment liquid, and a circulating tank containing a mixed solution prepared by mixing the washing water sent by the washing water sending pipe, and a dialysis treatment of the mixed solution contained in the circulating tank, A filter for separating into a concentrate and a permeate, and the concentration obtained by the filter; A concentrated liquid sending pipe for sending the liquid to the circulation tank, a permeated liquid sending pipe for sending the permeated liquid obtained by the filter to the washing tank, and a concentrated liquid contained in the circulation tank. And a mixed solution sending pipe for sending a mixed solution containing the mixed solution to the chemical conversion treatment tank.

Since any of the above <1> and <2> can embody the coating pretreatment method of the present invention,
The operation and effect of the coating pretreatment method of the present invention described above can be obtained. In particular, the <2> coating pre-treatment device of the second embodiment constitutes one circulation system with a circulation tank, a filter, and a concentrated solution sending pipe, and the filter is repeatedly concentrated, so that the processing capacity of the filter is reduced. Even if small, a concentrated solution having a high concentration can be efficiently obtained.

The coating pretreatment method of the present invention when applied to a method having a multi-stage (n-stage) water washing generally used in an automobile body line or the like, may be any one of the above <1> and <2>. It has the configuration of the coating pretreatment method of the present invention, has n stages of water washing means (n represents an integer of 2 or more), and
These washing means are arranged in series, and among the washing means arranged in series, overflow means for sending overflow water in the washing tank of the second to nth washing means to the washing tank of the preceding washing means is provided. The overflow water in the washing tank of the first-stage washing means is sent through the washing water sending pipe, and 1
The permeated liquid obtained by the filter is sent to a washing tank of any one or more washing means of the nth to nth stages.

In the coating pretreatment method and the coating pretreatment device of the present invention, the filter may be at least one selected from the group consisting of a nanofilter membrane, a reverse osmosis membrane, and a pressure dialysis membrane. preferable.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. [Principle of the present invention] First, the principle of the present invention will be described with reference to the drawings. The coating pretreatment method of the present invention includes at least a chemical conversion treatment step in which a chemical conversion treatment liquid accommodated in a chemical conversion treatment tank is brought into contact with an object to be treated to form a chemical conversion treatment on the object to be treated; One or more washing steps of contacting water with the object to be treated and washing the chemical conversion-treated object with water;
A pretreatment method for coating comprising a part of the chemical conversion treatment liquid contained in the chemical conversion treatment tank, and a part of the washing water contained in the water washing tank to prepare a mixed liquid, The mixed solution is dialyzed by a filter to be separated into a concentrated solution and a permeated solution, and the obtained concentrated solution is sent to the chemical conversion treatment tank, and the obtained permeated solution is sent to the washing tank. As a feature, in realizing the method, the coating pretreatment apparatus of the present invention to be used is, as described above, a <1> first mode and <2> a second mode.
There is a street. Hereinafter, the principle of the present invention will be described in detail while describing these embodiments.

<1> First Embodiment FIG. 1 is a schematic configuration diagram for explaining a first embodiment of a coating pretreatment apparatus of the present invention. Characteristic chemical treatment tank 12 and one rinsing tank 13, surface conditioning tank 11 as a pre-step of chemical conversion treatment,
In addition, only the periphery is extracted. Actually, for example, in the case of a zinc phosphate chemical conversion treatment, the surface conditioning tank 1
A degreasing tank and one or more degreased washing tanks are provided as pre-processes before 1 as a post-process after the rinsing tank 13.
A drying means is provided. In addition, water washing (tank) after chemical conversion treatment
Is one stage (one) in FIG. 1, but two stages (2
Generally)

The surface conditioning tank 11 and the chemical conversion tank 12 are dip tanks, and the object to be degreased and washed with water after degreasing advances in the direction of arrow A, and the surface adjustment tank 11 and the chemical conversion tank 12 ( The chemicals contained in the respective tanks are brought into contact with each other by being sequentially immersed and raised in the chemical conversion treatment step). At this time, the surface treatment liquid attached to the object to be treated in the surface adjustment tank 11 is carried into the chemical conversion treatment tank 12 as it is.

The surface conditioning liquid contained in the surface conditioning tank 11 may be of various compositions, and the chemical treatment liquid contained in the chemical treatment tank 12 is a zinc phosphate-based treatment liquid. In this case, the dispersion is generally a weak alkaline dispersion in which fine particles of titanium are dispersed, and a conventionally known dispersion is used without any problem. The surface conditioning tank 11 is not an essential component of the present invention, but is particularly desired in the case of a zinc phosphate chemical conversion treatment solution. As a general rule, a washing tank in the post-degreasing washing step is located.

As the chemical conversion treatment liquid accommodated in the chemical conversion treatment tank 12, in addition to the zinc phosphate type, an iron phosphate type chemical conversion treatment solution (above, a phosphate chemical conversion treatment solution), a chromate treatment solution,
Conventionally known surface treatment agents can be used as a coating base treatment agent such as an organic acid treatment solution. Among them, the zinc phosphate chemical conversion treatment solution contains phosphoric acid and zinc as main components, other heavy metals such as nickel and manganese, fluorine, NO _{3 and the} like as subcomponents, and further contains an oxidizing agent such as NO _{2 and the} like. It is a surface treatment agent and has good corrosion resistance of the formed film and good adhesion to the coating film.
It is frequently used in electrical component lines and the like.

The washing tank 13 is a spray tank, and the spray pipe is omitted in the drawing, but the object lifted from the chemical conversion treatment tank 12 proceeds in the direction of arrow A as it is and is disposed above the washing tank 13. The washing water contained in the washing tank 13 is brought into contact with the spray from the spray pipe thus sprayed (a washing step). The sprayed washing water is used to wash away the chemical conversion liquid adhering to the surface of the object to be treated, returned to the washing tank 13 and provided for circulation. The washing water stored in the washing tank 13 is supplied with water from a water supply pipe 14 or a permeated liquid feed pipe 23 described later so that the concentration of the chemical conversion treatment liquid does not become too high.
It is diluted at a predetermined dilution ratio.

In a general coating pretreatment apparatus, excess washing water due to water supply to the washing tank 13 is discharged out of the system as overflow water. An object of the present invention is to reuse such washing water.
The washing water overflowing the washing tank 13 is sent to the mixing tank 15 via the filter 18 by the washing water sending pipe 16. At this time, the chemical conversion treatment liquid is also sent from the chemical conversion treatment tank 12 through the chemical conversion treatment liquid supply pipe 17, and is combined with the washing water supply pipe 16 before the filter 18 to be mixed (mixing means). As the filter 18, the SS (Su) contained in the liquid is used.
Spended Solid) (garbage, sludge, etc.)
May be as simple as it can be recovered to some extent.

Incidentally, in FIG.
6 is formed by mixing the chemical conversion liquid sending pipe 17 with the chemical conversion treatment liquid to prepare a mixed liquid by mixing the washing water overflowing the water washing tank 13 with the chemical conversion liquid. It is not limited to the embodiment shown in FIG.
There is no problem if the liquid finally sent to the filter 21 described later is a mixed liquid. Therefore, the washing water supply pipe 1
6 and the chemical conversion liquid supply pipe 17 may be connected to the mixing tank 15 directly or via a filter 18, or the chemical conversion liquid supply pipe 17 may be joined to the washing water liquid supply pipe 16. In the state of FIG. 1, it may be sent to a filter 21 described later without passing through the mixing tank 15. In the former case, it is preferable to provide a stirring device in the mixing tank 15 in order to prepare a mixed solution by stirring the supplied washing water and the chemical conversion treatment solution.

In FIG. 1, the washing water overflowing from the washing tank 13 and the chemical conversion treatment liquid are sent once through a filter 18, but in the present invention, the filter 18 is optional. Element. Of course, in order to reduce the load on the filter described below, it is preferable to use the filter 18.

The mixed solution contained in the mixing tank 15 is sent to a filter 21 by a pump 20 and is subjected to a dialysis treatment.
The filter 21 includes a nanofilter membrane and a pressure dialysis membrane. One of these films may be used, or both may be used in combination.

For the nanofilter membrane, see, for example, the magazine “Chemical Equipment”, September 1995, p. 46 55 lines ~
67, Toshiro Otani et al., Industrial Research Institute Co., Ltd. and the like, and in the present invention, those described in such documents can be used without any problem.

For the reverse osmosis membrane (RO membrane), for example,
Published “Popular Edition Membrane Processing Technology” 1998.12.19, p. 10 line 61-p. Details are described in line 118, Fuji Techno System Co., Ltd., etc. In the present invention, those described in such documents can be used without any problem.

As for the pressure dialysis membrane, for example, Japanese Patent Application No.
It is described in detail in paragraphs 0010 to 0014 of JP-A-00-29193, and in the present invention, those described in such documents can be used without any problem.

When dialysis is performed using a nanofilter membrane or a pressure dialysis membrane, heavy metals such as zinc and nickel, phosphoric acid, fluorine, and the like, which are effective components of the chemical conversion treatment solution, are concentrated, and nitrate ions, which are unnecessary accumulation components, are removed. A concentrated solution that can be used as a chemical conversion solution can be obtained by removing ammonium ions, sodium ions, and the like.

Further, the permeate passed through the dialysis treatment is:
Since it is clean water having low electric conductivity, it can be used as washing water as it is or as deionized water in a deionized water washing step after further deionization treatment.

It is desirable to add an acid to the mixture before the dialysis treatment is performed with a nanofilter membrane or a pressure dialysis membrane. By adding the acid, it is possible to prevent a trouble that a precipitate is deposited on the nanofilter membrane or the pressure dialysis membrane during the dialysis treatment. As the acid that can be added, those that are included as components in the chemical conversion treatment liquid are preferable,
When the phosphating solution is used as a chemical conversion solution, it is desirable to add phosphoric acid. Although the amount of the acid to be added cannot be specified unconditionally, it is desirable that the concentration of the acid in the mixed solution after the addition of the acid is about 1 to 10 g / l.

The concentrate obtained by the filter 21 is
It is sent to the chemical conversion treatment tank 12 by the concentrated solution sending pipe 22,
The permeated liquid obtained by the filter 21 is sent to the washing tank 13 through the permeated liquid sending pipe 23. At this time, although the amount of the concentrated solution to be sent to the chemical conversion treatment tank 12 depends on the composition of the concentrated solution, it is within 5% per hour with respect to the total amount of the chemical conversion treatment liquid accommodated in the chemical conversion treatment tank 12. It is more preferable that it is within 1%. In the present invention, the composition of the obtained concentrated liquid is close to that of the chemical conversion treatment liquid, but it is preferable to observe the above rules in order to further reduce the fluctuation of the composition balance of the chemical conversion treatment liquid. As described above, the washing water that overflows the washing tank 13 is effectively reused as the chemical conversion treatment liquid and the washing water.

<2> Second Embodiment FIG. 2 is a schematic configuration diagram for explaining a second embodiment of the coating pretreatment apparatus of the present invention. As in FIG. The surface adjustment tank 11, the chemical conversion tank 12, the water washing tank 13, and only the peripheral portion thereof are extracted. In the second embodiment, most of the components are the same as those in the first embodiment. In FIG. 2, the members denoted by the same reference numerals as those in FIG. 1 are members having the same functions as those in FIG. And its detailed description is omitted.

As in the case of the first embodiment, the object to be treated is the surface conditioning tank 1.
1. Chemical conversion tank 12 (chemical conversion step) and washing tank 13
In the (washing step), the liquids are sequentially contacted and processed. In the process, the washing water stored in the washing tank 13 is supplied to the water supply pipe 14.
In addition, the water supplied from the permeated liquid feed pipe 23 causes excess concentration of the washing water to be diluted at a predetermined dilution ratio so that the concentration of the chemical conversion treatment solution does not become too high.

The rinsing water overflowing the rinsing tank 13 is sent to the circulation tank 19 through the filter 18 by the washing water feed pipe 16. At the same time, the chemical conversion treatment liquid is also sent from the chemical conversion treatment tank 12 by the chemical conversion treatment liquid supply pipe 17, merges with the washing water supply pipe 16 before the filter 18, and flows into the circulation tank 19 via the filter 18. It is sent. The fact that the filter 18 is an optional element is the same as in the first embodiment.

The connection between the washing water supply pipe 16 and the chemical conversion treatment liquid supply pipe 17 is not limited to the embodiment shown in FIG.
It may be connected so that the washing water overflowing is mixed with the chemical conversion treatment liquid.

In the circulation tank 19, a stirrer (not shown) is provided to stir the supplied washing water and the chemical conversion treatment liquid to prepare a mixed liquid. However, as shown in FIG.
The washing water and the chemical conversion treatment liquid may be mixed before being sent to the circulation tank 19, or the washing water and the chemical conversion treatment liquid to be sent may be mixed.
Alternatively, if a later-described concentrated liquid is discharged into the circulation tank 19 so as to generate a vortex in the circulation tank 19, the stirring device may be omitted.

The mixed solution contained in the circulation tank 19 is sent to a filter 21 by a pump 20 and subjected to dialysis.
In the second embodiment, the permeated liquid obtained by the filter 21 is sent to the washing tank 13 by the permeated liquid feed pipe 23 as in the first embodiment, but the concentrated liquid obtained by the filter 21 is The circulating tank 19 is provided by the concentrated solution sending pipe 22 '.
The liquid is sent to That is, the circulation tank 19, the pump 20, the filter 21, and the concentrated liquid sending pipe 22 'constitute one circulation system. Therefore, the mixed solution accommodated in the circulation tank 19 is circulated through the circulation system so that
The mixture is repeatedly concentrated by the step 1, and as a result, the mixed liquid becomes a concentrated liquid.

The mixed liquid that is the concentrated liquid contained in the circulation tank 19 (in the present invention, such a mixed liquid that is the concentrated liquid is referred to as “mixed liquid containing the concentrated liquid”) is washed with fresh water. When the water and the chemical conversion treatment liquid are sent to the circulation tank 19, they overflow into the overflow pan 24, and are further sent to the chemical conversion treatment tank 12 through the mixed solution supply pipe 25.

At this time, the amount of the mixed solution containing the concentrated solution sent to the chemical conversion treatment tank 12 depends on the composition of the concentrated solution.
1 to the total amount of the chemical conversion solution stored in the chemical conversion tank 12
It is preferably within 5% per hour, more preferably within 1%. In the present invention, the composition of the obtained concentrated liquid is close to that of the chemical conversion treatment liquid, but it is preferable to observe the above rules in order to further reduce the fluctuation of the composition balance of the chemical conversion treatment liquid.

The washing water overflowing the washing tank 13 as described above is effectively reused as the chemical conversion treatment liquid and the washing water. In particular, in the second embodiment, the filter 2
Since the concentration is repeatedly performed by step 1, a concentrated solution having a high concentration can be efficiently obtained even if the processing capacity of the filter 21 is small.

In the first and second embodiments, the surface adjusting tank 11 and the chemical conversion tank 12 are dip tanks, and the washing tank 13 is a spray tank. However, the present invention is not limited to this, and in the present invention, each of these tanks can take any form of a dip tank and a spray tank.

In the first and second embodiments, the washing water overflowing from the washing tank 13 is sent to the circulation tank 19 by the washing water sending pipe 16. There is no problem in the present invention as long as a part of the washing water stored in the washing tank 13 is sent, for example, the washing water stored in the washing tank 13 is extracted. Similarly, the surface conditioning tank 11 and the chemical conversion tank 12 may be either a dip tank or a spray tank.

[Volume Balance and Substance Balance of Chemical Conversion Treatment Solution in the Present Invention] The volume balance of the chemical conversion treatment solution in the present invention will be described. As described in the first and second examples, the surface treatment liquid attached to the object to be treated in the surface adjustment tank 11 is carried into the chemical treatment tank 12 as it is. That is, even if the chemical conversion treatment liquid is taken out to the washing tank 13, the capacity balance is approximately ± 0. Therefore, the decrease in the amount of the chemical conversion treatment liquid from the chemical conversion treatment tank 12 is mainly caused by evaporation from the opening of the chemical conversion treatment tank 12. If it is a high-temperature type chemical treatment liquid, the amount of the chemical conversion treatment liquid due to the evaporation will be reduced to some extent.
It is not expected that the amount of the chemical conversion solution is reduced by the evaporation.

Therefore, if the overflow water in the washing tank is simply concentrated by a filter and used as a chemical conversion solution, the decrease in the chemical conversion solution cannot keep up with the increase due to the supplied washing water concentrate, and The treatment liquid overflows the chemical conversion treatment tank. In recent years, from the viewpoint of energy saving, the temperature of the chemical conversion treatment liquid has been reduced, and from such a background, it has been difficult to reuse the washing water after the chemical conversion treatment. In the present invention, since the chemical conversion treatment liquid is also subjected to concentration by the filter together with the washing water after the chemical conversion treatment (the chemical conversion treatment liquid is reduced by this amount), even if the obtained concentrated liquid is supplied to the chemical conversion treatment tank, The chemical conversion solution does not increase.

The capacity balance will be described more specifically with reference to an automobile body line as an example. According to calculations by the inventors, for example, in a chemical conversion tank having a tank capacity of 200 m ^{3 in} an automobile line, the amount of water evaporated from the opening of the chemical conversion tank is about 60 ° C. when the temperature of the chemical conversion liquid is 60 ° C. 540 liters / hr, about 340 liters / hour at 50 ° C.
hr, about 200 liters / hr at 40 ° C., about 1 at 35 ° C.
The liquid level is 30 liters / hr, and if no water is supplied, the liquid level drops accordingly.

Regarding the overflow water in the washing tank 13,
If it is simply concentrated by a filter such as a nanofilter membrane, a reverse osmosis membrane, or a pressure dialysis membrane, and it is intended to replenish it to the chemical conversion treatment solution, the amount of the washing water concentrate in this case is, of course, the processing capacity of these filters. Although it varies depending on the size of the object to be treated, the amount of treatment, and the like, one standard assuming a general line and a general filter is about 250 liters / hr. Therefore, there is no problem when the temperature of the chemical conversion treatment liquid is 60 ° C. or 50 ° C.
The loss due to the evaporation of the chemical conversion liquid cannot keep up with the increase due to the supplied washing water concentrate, and the chemical conversion liquid overflows the chemical conversion tank.

However, in the coating pretreatment apparatus or the coating pretreatment method of the present invention, the chemical conversion treatment liquid in the chemical conversion treatment tank 12 is withdrawn and mixed with the overflow water in the washing tank 13.
Since the dialysis treatment is performed by the filter 21, for example, the dialysis treatment is performed by the filter 21 so that the amount thereof becomes the same as the amount of the chemical treatment liquid extracted from the chemical treatment tank 12, and the dialysis treatment is sent to the chemical treatment tank 12. If it is to be liquefied, chemical conversion tank 1
2 does not overflow.

Next, the material balance of the chemical conversion treatment liquid according to the present invention will be described. The composition of the concentrated solution sent to the chemical conversion treatment tank 12 is strictly different from the composition of the chemical conversion treatment solution. However, the chemical conversion treatment liquid usually takes into account components that are easily consumed and components that are not easily consumed, depending on the treatment of the object to be treated,
By constantly replenishing the balanced replenisher constantly or intermittently while checking the concentration of the chemical conversion solution,
By keeping the composition ratio constant and finely adjusting the component ratio of the replenisher, the composition ratio of the chemical conversion treatment liquid when the present invention is applied can be kept constant.

In particular, when a nanofilter membrane or a pressure dialysis membrane is used as the filter 21, monovalent ions are preferentially permeated, and heavy metals such as zinc and nickel, phosphoric acid, fluorine and the like, which are effective components of the chemical conversion treatment solution. Can be concentrated, and the unnecessary accumulation components such as nitrate ion, ammonium ion, sodium ion and the like can be removed. Therefore, the concentrated liquid sent to the chemical conversion treatment tank 12 has a composition balance close to that of the chemical conversion treatment liquid, and the component ratio of the replenisher can be sufficiently adjusted by a slight adjustment.

[Line Development of the Present Invention] The coating pretreatment method and the coating pretreatment device of the present invention can be applied as a coating pretreatment method and a coating pretreatment device for any coating pretreatment line. Hereinafter, the present invention will be described with reference to an embodiment in which the painting pretreatment method and the painting pretreatment device of the present invention are applied to a typical automobile body line.

(First Embodiment) FIG. 3 is a schematic configuration diagram of a pretreatment apparatus for coating according to a first embodiment to which the first embodiment of the pretreatment apparatus for coating according to the present invention is applied. The pretreatment apparatus for coating according to the present embodiment includes a first degreasing tank 46 forming a first degreasing step, a second degreasing tank 47 forming a second degreasing step, and a first washing step forming a first washing step after degreasing. A tank 48, a second washing tank 49 constituting a second post-degreasing washing step, a surface conditioning tank 31 constituting a surface conditioning step, a chemical treatment tank 32 constituting a chemical conversion step, and a first washing step after chemical formation , A fourth rinsing tank 50 forming a second rinsing step after chemical formation, a fifth rinsing tank 51 forming a third rinsing step after chemical formation, and a fourth rinsing step forming a deionized rinsing step. 6 washing tank 52
Are arranged in series, and while the object to be processed is transported in the direction of arrow B, the object is sequentially brought into contact with the liquid stored in each tank in each step to perform processing or washing. The water washing step after chemical formation in this embodiment is a multi-stage water washing, and the number of steps is four (n = 4).

Although the drying step is omitted in FIG. 3, the deionized water adhered (substituted) in the deionized water washing step is generally used to dry the water, and the deionized water is used for the next coating step. After the water washing step, a drying step using a hot air heater or the like follows. In addition, prior to providing the object to be treated in the first degreasing step, debris such as iron powder and fiber waste adhering to the object to be treated is washed out, or the temperature of the object to be treated is increased by degreasing in the first and second degreasing steps. A pre-cleaning or pre-hot water washing step may be provided for the purpose of increasing the power or the like.

The first degreasing tank 46 constituting the first degreasing step,
Further, the second degreasing tank 47 constituting the second degreasing step is a dip tank, and the objects to be treated, which are put into the pretreatment device for coating of the present embodiment, are sequentially placed in the first degreasing tank 46 and the second degreasing tank 47. It is immersed and brought into contact with the degreasing solution contained in each tank to remove oil and dust adhering to the surface. As the degreasing liquid stored in the first degreasing tank 46 and the second degreasing tank 47, any of those conventionally used as a degreasing liquid in a coating pretreatment step can be used. Generally, an alkali component is used as a builder. An alkali degreasing agent containing a surfactant is used.

The first rinsing tank 48 constituting the first post-degreasing rinsing step and the second rinsing tank 49 constituting the second post-degreasing rinsing step are spray tanks. Proceeds in the direction of arrow B, and is sprayed in the first and second washing tanks 48 and 49 in order to wash off the degreasing solution adhering to the surface. By taking out the degreasing solution from the second degreasing step, the first washing tank 48 and the second washing tank 4
Although the degreasing liquid is brought into the tank 9, industrial water is supplied from the water supply pipe 53 to the second washing tank 49, and the overflow water in the second washing tank 49 is sent to the first washing tank 48 by the overflow means 54. By using a so-called pre-stage feeding structure, accumulation of the degreasing liquid is prevented, and the water quality of both washing tanks is at least a certain level.

In all the washing tanks including each washing step after the chemical conversion treatment to be described later, the spray piping is omitted in the drawing, but the object to be treated conveyed to each washing tank is located in the upper part of each washing tank. The washing water contained in each washing tank is brought into contact with the water by spraying from a spray pipe arranged in the washing tank.

The overflow water in the first washing tank 48 is discharged through a drain pipe 55. The discharged overflow water in the first washing tank 48 is generally subjected to drainage treatment and then discharged. However, the overflow water is cleaned by a known filtration and / or separation means to perform a degreasing step and / or
Alternatively, it is preferable to reuse in the washing step. By doing so, it is possible to achieve a closed circulation type of the entire coating pretreatment apparatus in combination with the effects of the present invention. In addition, when the preliminary cleaning or preliminary hot water washing step is not provided before the first degreasing step, the concentrated solution of the degreasing liquid is supplied to the first degreasing tank 46 constituting the first degreasing step without being brought in from the previous step. Even if it is added, the liquid level hardly rises too much.

The surface conditioning tank 31 constituting the surface conditioning step,
The chemical conversion treatment tank 32 constituting the chemical conversion treatment step is a dip tank, and after the second dewatering step, the object to be treated advances in the direction of arrow B, and is sequentially immersed in the surface adjustment tank 31 and the chemical conversion treatment tank 32. As a result, the chemicals contained in the respective tanks come into contact with each other.

Further, a third washing tank 33 constituting a first washing step (first stage) after chemical formation, a fourth washing tank 50 constituting a second washing step (second stage) after chemical formation, a third washing step after chemical formation. The fifth washing tank 51 constituting the step (third stage) and the sixth washing tank 52 constituting the deionized washing step (fourth stage) are all spray tanks. The object proceeds in the direction of arrow B, and the third washing tank 33, the fourth washing tank 50,
In the fifth rinsing tank 51 and the sixth rinsing tank 52, the chemical conversion treatment liquids which are sequentially sprayed and adhere to the surface are washed away. By taking out the degreasing liquid from the chemical conversion treatment step, the chemical conversion treatment liquid is brought into each of the washing tanks after the chemical conversion treatment.

Also in each of the washing tanks after the chemical conversion treatment, the upstream stage of the overflow water is carried out. Deionized water is supplied to the sixth washing tank 52 from a deionized water supply pipe 56, and overflow water of the sixth washing tank 52 is sent to the fifth washing tank 51 by overflow means 57. The deionized water supplied from the deionized water supply pipe 56 is desirably supplied to the sixth washing tank 52 from the riser pipe at the end of the deionized water washing step in such a manner that the deionized water is sprayed on the object to be treated in the form of a mist. .

In the fifth washing tank 51, the water supply pipe 3
After the industrial water is supplied from 4, the overflow water in the fifth washing tank 51 is sent to the fourth washing tank 50 by the overflow means 58. Similarly, in the fourth washing tank 50,
The overflow water is sent to the third washing tank 33 by the overflow means 59.

That is, the third (first stage) arranged in series
The overflow water in the fourth to sixth (second to n-th) washing tanks 50 to 52 of the fourth to sixth (second to n-th) washing tanks 50 to 52 is the following. The overflow means 57 to 58 have a front-stage feed structure in which the liquid is sent to each of the washing tanks at the front stage.

The washing water in the third (first-stage) washing tank 33 is diluted to about 1/5 to 1/50 (dilution factor 5 to 50 times) with respect to the ordinary chemical conversion treatment liquid. The overflow water in the third (first-stage) washing tank 33 is sent to the filter 21 through the washing water supply pipe 36. At this time, the chemical conversion treatment liquid is also sent from the chemical conversion treatment tank 12 by the chemical conversion treatment liquid supply pipe 17, and is joined and mixed in the middle of the washing water supply pipe 36 (mixing means). In the present embodiment, the liquid is sent to the filter 21 without passing through the filter. However, the liquid may be sent to the filter 21 after passing through the filter.

The overflow water in the washing tank 33 and the chemical conversion solution sent to the filter 21 are dialyzed,
It is separated into concentrate and permeate. The obtained concentrated liquid is sent to the chemical conversion treatment tank 32 by the concentrated liquid sending pipe 42, and the obtained permeated liquid is sent to the fifth washing tank 5 by the permeated liquid sending pipe 43.
1 and is supplied to the water supply resources in the post-chemical washing step together with the industrial water from the water supply pipe 34. As described above, the washing water overflowing the washing tank 33 is effectively reused as the chemical conversion treatment liquid and the washing water.

(Second Embodiment) Next, a second embodiment will be described. FIG. 4 is a schematic configuration diagram of a coating pretreatment device of a second embodiment to which the second embodiment of the coating pretreatment device of the present invention is applied. However, in FIG. 4, the configurations of the respective tanks constituting the first degreasing step, the second degreasing step, the first rinsing step after degreasing, and the second rinsing step after degreasing are the same as those in FIG. I have. In addition, since most of the configuration after the surface adjustment step is the same as that of the first embodiment, members having the same functions as those of the first embodiment include:
The same reference numerals as those in FIG. 3 are used, and the detailed description is omitted.

Also in the present embodiment, the third (first-stage) washing tank 33 and the fourth to sixth (2-n)
Of the washing tanks 50 to 52 of the (stage), the fourth to sixth (2-n
The overflow water in the washing tanks 50 to 52 of the (stage) is sent to the preceding washing tanks by overflow means 57 to 58, respectively, so that the water is sent to the preceding washing tank. However, no industrial water was supplied in the fifth washing.

The overflow water in the third (first stage) washing tank 33 is supplied to the filter 3 by the washing water feed pipe 36 '.
The liquid is sent to the circulation tank 39 through 8. At the same time, the chemical conversion treatment liquid is also sent from the chemical conversion treatment tank 32 by the chemical conversion treatment liquid supply pipe 37 ′, and the washing water supply pipe 36 is provided before the filter 38.
And is sent to the circulation tank 39 via the filter 38. Of course, filter 38 is an optional element. Circulation tank 19
The mixed liquid stored in the filter 4 is
1 to be dialyzed.

In this embodiment, the permeated liquid obtained by the filter 41 is sent to the sixth washing tank 52 via the permeated liquid feed pipe 43 ′ via the pure water producing device 60. Examples of the pure water production device 60 include a device using a reverse osmosis membrane (RO membrane) and an ion exchange resin. Since the permeated liquid is clean water having low electric conductivity, when the deionized water is produced by the pure water producing apparatus 60 using the permeated liquid, R
The deterioration of the O membrane and the ion exchange resin is not accelerated.

On the other hand, the concentrated liquid obtained by the filter 41 is sent to the circulation tank 39 through the concentrated liquid sending pipe 42 '. That is, the circulation tank 39, the pump 40, the filter 41, and the concentrated liquid sending pipe 42 'constitute one circulation system. Therefore, the liquid mixture contained in the circulation tank 39 is repeatedly concentrated by the filter 41 by circulating through the circulation system, and as a result, the liquid mixture becomes a concentrated liquid.

The mixed liquid, which is the concentrated liquid stored in the circulation tank 39, overflows into the overflow pan 44 when the new washing water and the chemical conversion treatment liquid are sent to the circulation tank 39, and the mixed liquid is further sent. The liquid is sent to the chemical conversion treatment tank 32 through the pipe 45. As described above, the washing water overflowing the washing tank 33 is effectively reused as the chemical conversion treatment liquid and the washing water. In particular, in the present embodiment, since the concentration is repeated by the filter 41, the filter 4
Even if the processing capacity of (1) is small, a concentrated solution having a high concentration can be efficiently obtained.

As described above, the present invention has been described with reference to the embodiments. However, the present invention is not limited to the configurations of the above embodiments, and those skilled in the art may add conventionally known knowledge to the configurations of the present invention and / or As long as it can be replaced and has the configuration of the present invention, it is of course included in the category of the present invention.
For example, one or more of the tanks in the above embodiment may be replaced between the dip tank and the spray tank, or the number of steps may be increased or decreased. The case where the number of washing steps (n) is four (n = 4) has been described. However, three or less or five or more steps may be used.

Further, in the above embodiment in which n = four-stage water washing, the filtrate obtained by the dialysis treatment is used for the fifth washing.
Although the liquid is sent to the washing tank (n-1 stage) or the sixth washing tank (n stage), the liquid may be sent to any of the third (1st) to 6th (n stage) washing tanks. I do not care. However, the filtrate obtained by the dialysis treatment is sufficiently clean, and it is preferable that the filtrate be sent to a second-stage (second or later) washing tank where cleanliness is required. In the coating pretreatment apparatus having the above, it is particularly preferable to feed the liquid to an n-1 or n-stage washing tank in order to achieve a closed circulation type of the entire apparatus.

[0085]

The present invention will be specifically described below with reference to examples. <Example 1> The effects of the coating pretreatment method and the coating pretreatment device of the present invention were confirmed on an actual automobile body line. More specifically, a circulating tank 39 having a flush water supply pipe 36 ′, a chemical conversion treatment liquid supply pipe 37 ′, a filter 38, an overflow pan 44, a pump 40, A filter 41, a concentrated solution sending pipe 42 ', a permeated solution sending pipe 43', a mixed solution sending pipe 45, and a pure water production apparatus 60 are installed, and the configuration of the present invention shown in FIG. Was prepared as shown in FIG. 3).

In this automobile body line, the chemical conversion tank 32 has a tank capacity of 200 m ³ , and the third washing tank 3
The tank capacities of the third, fourth, fifth and sixth washing tanks 50, 51 and 52 are all 5 m ³ . In addition, the chemical conversion solution brought out by the object to be treated is 250 liter / hr.
The capacity of the overflow water in the third washing tank 33 is 5 m ³ / hr. Therefore, the third washing tank 33
The dilution ratio of the chemical conversion solution is (5 m ³ / hr) ÷
(250 liters / hr) = 20 times.

The temperature of the chemical conversion treatment liquid in the chemical conversion treatment tank 32 is 35 ° C., and 130 liter / hr of water is evaporated from the liquid surface. In addition, the third washing tank 33, the fourth washing tank 5
The water temperatures of the 0, the fifth washing tank 51 and the sixth washing tank 52 are normal temperature (about 20 ° C.).
0 liter / hr of water is evaporated, and the same amount of deionized water is supplied from the deionized water supply pipe 56 to make up for it. The deionized water is supplied to the sixth rinsing tank 52 from the riser pipe at the end of the deionized water rinsing step in such a manner that the deionized water is sprayed on the object in a mist form.

The pH of the chemical conversion treatment liquid and the washing water contained in the third washing tank (hereinafter simply referred to as “third washing water”),
And measurement of electrical conductivity, and the main chemical component (Zn
²⁺ , Ni ²⁺ , PO ₄ ³⁻ , NO ₃ ⁻ , Na ⁺ , NH ⁴⁺ ) were quantified, and the results are as shown in Table 1 below. In addition,
The free acidity (FA) and the total acidity (TA) were measured by the following methods. In addition, the chemical conversion treatment liquid was also measured for the free acidity (FA), total acidity (TA), and accelerator (oxidizing agent) concentration (AC) shown below.

Free acidity (FA) When 10 ml of a sample to be measured is collected, several drops of bromophenol blue indicator are dropped, and titration is performed with a 0.1 mol / l aqueous sodium hydroxide solution until the yellow color becomes blue-violet. Is expressed as points (pt).

Total acidity (TA) When 10 ml of a sample to be measured is collected, several drops of a phenolphthalein indicator are dropped, and titration is performed with a 0.1 mol / l aqueous sodium hydroxide solution until a pink color is obtained. Is expressed as points (pt).

Accelerator concentration (AC) Sulfamic acid is excessively added to 50 ml of a sample to be measured, the volume of generated gas is determined, and the number of ml is expressed as points (pt). Actually, it was measured using a saccharometer.

A white body of an automobile as an object to be treated was sequentially put into the above-mentioned coating pretreatment apparatus, and a conversion coating of zinc phosphate was formed on the surface thereof. At this time, the third washing tank 3
For the overflow water of No. 3, the following treatment was performed.

From the chemical conversion tank 32 to the chemical conversion liquid supply pipe 3
7 'chemical conversion solution 250 l / hr by is fed, wash water liquid feed pipe 36' third overflow water in the washing tank 33 which is fed by a (5 m ³ / hr) mixed with 5.25M ³ / hr and is stored in a circulation tank 39 via a filter 38. As for the mixed solution before being accommodated in the circulation tank 39 (hereinafter, referred to as “mixture before treatment”), the measurement of the concentration of the chemical solution and the quantification of the components of the chemical solution were performed in the same manner as the third washing water. The results are shown in Table 1 below.

The mixed solution contained in the circulation tank 39 is sent to a filter 41 by a high-pressure pump 40. In the present embodiment, as a filter 41, a nano filter membrane SU210 manufactured by Toray having 24 modules each having a liquid contact area of 6.9 m ² per filter was installed. The dialysis treatment was performed by the filter 41 to separate into a permeated liquid of 5 m ³ / hr and a concentrated liquid of 250 l / hr. That is, the concentration rate of the concentrated liquid is (5.25 m ³ / hr) ÷ (2
50 liters / hr) = 21 times. The permeation amount per unit area of the nanofilter membrane was 60.0 liter / m ² · hr. As for the permeated liquid, the measurement of the concentration of the chemical solution and the quantification of the components of the chemical solution were performed in the same manner as in the third washing water. The results are shown in Table 1 below.

The permeate obtained by the filter 41 is
The sixth through the pure water production device 60 in the permeated liquid feed pipe 43 ′
The liquid is sent to the washing tank 52. At this time, the permeated liquid was supplied by the pure water production device 60 to have an electric conductivity of 100 to 1000 μS /
and then sent to the sixth washing tank 52.

On the other hand, the concentrated liquid obtained by the filter 41 is sent to the circulation tank 39 by the concentrated liquid sending pipe 42 ', and is composed of the circulating tank 39, the pump 40, the filter 41, and the concentrated liquid sending pipe 42'. Configure the circulatory system. The mixed solution containing the concentrated liquid stored in the circulation tank 39 is repeatedly concentrated by the filter 41 by circulating through the circulation system, and new washing water and the chemical conversion treatment liquid are sent to the circulation tank 39. It overflows to the overflow pan 44, and furthermore, the chemical conversion tank 3
Liquid is sent to 2. At this time, the mixed liquid containing the concentrated liquid sent through the mixed liquid sending pipe 45 (hereinafter, referred to as “mixed liquid after treatment”) is 250 liters / hr. In the same manner, the measurement of the drug solution concentration and the like (excluding AC) and the quantitative determination of the drug solution components were performed. The results are shown in Table 1 below.

<Embodiment 2> In Embodiment 1, the amount of the chemical conversion treatment liquid fed from the chemical conversion treatment tank 32 by the chemical conversion treatment liquid supply pipe 37 'was changed from 250 liter / hr to 1 m.
³ / hr, and in accordance with this, the flow rate of the permeate after the dialysis treatment by the filter 41 is 5 m ³ / hr, the flow rate of the concentrated solution is 1 m ³ / hr, and the flow of the mixed liquid after the treatment is further performed. The treatment of the object was performed in the same manner as in Example 1 except that the amount was set to 1 m ³ / hr. Note that the concentration rate of the concentrated liquid is (6 m ³ / hr) ÷ (1 m ³ / hr) = 6 times.
The permeation amount of the nanofilter membrane per unit area is 4
It was 7.0 liter / m ² · hr. In the same manner as in Example 1, for the mixed solution before the treatment, the permeated solution, and the mixed solution after the treatment, the measurement of the chemical solution concentration and the like and the quantitative determination of the chemical solution components were performed.
The results are shown in Table 1 below.

[0098]

[Table 1]

As shown in Table 1, the mixed solution after the treatment was close to the concentration and components of the chemical conversion treatment solution in both Examples 1 and 2.
Further, the supply amount A of the post-treatment mixture per hour with respect to the total amount of the chemical conversion treatment solution T (200 m ³ ) (250 liter / h)
r or 1 m ³ / hr) (A / T × 100%)
However, since it is less than 1%, component fluctuation of the chemical conversion treatment liquid is at a level that causes almost no problem. Strict concentration adjustment can be sufficiently reviewed with a replenisher for a chemical conversion treatment solution.

Therefore, according to Embodiments 1 and 2 in which the nanofilter membrane is used as the filter 41, the washing water overflowing the third washing tank 33 can be effectively reused as a chemical conversion treatment liquid and washing water. Understand. Also, the system is a completely closed system except that the SS component accumulated in the filter 38 must be cleaned.

<Example 3> In the example 1, the nanofilter membrane used for the filter 41 was equipped with 24 modules each having a liquid contact area of 6.9 m ² per functional membrane process design. Office-made pressure dialysis membrane MD-K
Except that the mold was replaced, the processing of the object was performed in the same manner as in Example 1. In the same manner as in Example 1, for the mixed solution before the treatment, the permeated solution, and the mixed solution after the treatment, the measurement of the chemical solution concentration and the like and the quantitative determination of the chemical solution components were performed. The results are shown in Table 2 below.

<Example 4> In Example 2, the functional filter process design was carried out in which 24 modules each having a liquid contact area of 6.9 m ² per nano filter membrane used for the filter 41 were installed. Office-made pressure dialysis membrane MD-K
The processing of the processing object was performed in the same manner as in Example 2 except that the mold was replaced. In the same manner as in Example 1, for the mixed solution before the treatment, the permeated solution, and the mixed solution after the treatment, the measurement of the chemical solution concentration and the like and the quantitative determination of the chemical solution components were performed. The results are shown in Table 2 below.

[0103]

[Table 2]

As shown in Table 2, the mixed solution after the treatment was close to the concentration and components of the chemical conversion treatment solution in both Examples 3 and 4.
It can be seen that even if a pressure dialysis membrane is used for the filter 41, the washing water overflowing the third washing tank 33 can be effectively reused as a chemical conversion treatment liquid and washing water, as in Examples 1 and 2. Also, the system is a completely closed system except that the SS component accumulated in the filter 38 must be cleaned.

[0105]

As described above, according to the present invention, in consideration of the volume balance and the material balance of the chemical conversion treatment solution, it is difficult to reuse the washing water after the chemical conversion treatment, which was difficult to reuse, as the washing water. Of course, it is possible to provide a coating pretreatment method and a coating pretreatment device that can minimize waste by collecting and reusing chemical conversion treatment liquid components. In addition, the present invention facilitates the recovery of the rinse water after the chemical conversion treatment, which was difficult to reuse, so that the coating pretreatment equipment (painting pretreatment line) can achieve a closed circulation system. A pretreatment method and a coating pretreatment device can be provided.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram for explaining a first embodiment of a coating pretreatment device of the present invention.

FIG. 2 is a schematic configuration diagram for explaining a second embodiment of the coating pretreatment device of the present invention.

FIG. 3 is a schematic configuration diagram of a coating pretreatment device of the first embodiment to which the first embodiment of the coating pretreatment device of the present invention is applied.

FIG. 4 is a schematic configuration diagram of a coating pretreatment device of a second embodiment to which a second embodiment of the coating pretreatment device of the present invention is applied.

[Explanation of symbols]

 11, 31 Surface conditioning tank 12, 32 Chemical treatment tank 13 Rinse tank 14, 34, 53 Water supply pipe 15 Mixing tank 16, 36 Rinse water supply pipe 17, 37 Chemical conversion liquid supply pipe 18, 38 Filter 19, 39 Circulation tank 20, 40 Pump 21, 41 Filter 22, 22 ', 42, 42' Concentrated liquid feed pipe 23, 23 ', 43, 43' Permeate feed pipe 24, 44 Overflow pan 25, 45 Mixed liquid feed Piping 33 Third washing tank 46 First degreasing tank 47 Second degreasing tank 48 First washing tank 49 Second washing tank 50 Fourth washing tank 51 Fifth washing tank 52 Sixth washing tank 54, 57, 58, 59 Overflow means 55 drainage pipe 60 pure water production equipment

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C02F 1/44 C02F 1/44 E C23C 22/86 C23C 22/86 (72) Inventor Shinichi Tsubaki Central Tokyo 1-15-1, Nihonbashi-ku, Japan Inside Parkerizing Co., Ltd. (72) Inventor Noriaki Kobayashi 2-16-9, Nihonbashi, Chuo-ku, Tokyo Parker Engineering Co., Ltd. F-term (reference) 4D006 GA03 GA06 GA13 GA13 JA56A KA01 KA63 KA71 MA40 PB07 PB08 PC80 4D075 AB12 AB34 AB41 BB73X CA47 DA23 DB02 DC12 EA06 4F040 AA13 AB20 BA48 CC09 CC10 DB04 4F042 AA09 CA01 CB08 CB25 CB27 CC04 4K026 AA02 BA03 BA04 DA18 DA19

Claims (7)

[Claims] At least a chemical conversion treatment step in which a chemical conversion treatment liquid contained in a chemical conversion treatment tank is brought into contact with a substance to be treated to form a chemical conversion treatment on the substance to be treated; 1 to wash the chemical conversion-treated object with water
A pre-coating treatment method comprising at least two stages of washing steps, wherein a part of the chemical conversion treatment liquid accommodated in the chemical conversion treatment tank and a part of the washing water accommodated in the washing tank are mixed. To prepare a mixed solution, the mixed solution is dialyzed with a filter to separate into a concentrated solution and a permeate, and the obtained concentrate is sent to the chemical conversion treatment tank, and the obtained permeate is sent to the water washing tank. And a coating pretreatment method, wherein each liquid is sent. 2. The coating pretreatment method according to claim 1, wherein the washing step has n stages (n represents an integer of 2 or more), and the washing steps are sequentially performed. Of these rinsing steps, overflow water in the rinsing tanks of the second to nth rinsing steps is respectively sent to the rinsing tanks of the preceding rinsing step, and the overflow water in the rinsing tanks of the first rinsing step is Used for preparing a mixed solution to be subjected to the dialysis treatment by the filter, and sending the filtrate obtained by the dialysis treatment to a washing tank in one or more washing steps of the first to nth stages. Characteristic coating pre-treatment method. 3. The method according to claim 1, wherein the filter is a nanofilter membrane,
The coating pretreatment method according to claim 1 or 2, wherein the method is at least one selected from the group consisting of a reverse osmosis membrane and a pressure dialysis membrane. 4. A chemical conversion treatment means for causing at least the chemical conversion treatment liquid contained in the chemical conversion treatment tank to come into contact with the object to be treated to form a chemical conversion treatment on the object to be treated; A coating pretreatment device comprising at least one stage of water washing means for contacting the object with the object and washing the object subjected to the chemical conversion treatment with water. A chemical conversion treatment liquid sending pipe for sending a part, a washing water sending pipe for sending a part of the washing water contained in the washing tank, and a chemical treatment sent by the chemical treatment solution sending pipe. Processing solution,
And the washing water sent by the washing water sending pipe,
Mixing means for preparing a mixed solution by mixing the solution, a filter for subjecting the mixed solution to dialysis treatment and separating it into a concentrated solution and a permeate, and a concentration for sending the concentrated solution obtained by the filter to the chemical conversion treatment tank. A coating pretreatment device, comprising: a liquid feed pipe; and a permeate feed pipe for sending a permeate obtained by the filter to the washing tank. 5. A chemical conversion treatment means for causing at least a chemical conversion treatment liquid contained in a chemical conversion treatment tank to come into contact with an object to be treated to form a chemical conversion treatment on the object to be treated; A coating pretreatment apparatus comprising: one or more stages of water washing means for contacting the object with water and washing the chemical conversion-treated object with water; A chemical conversion treatment liquid sending pipe for sending the liquid, a washing water sending pipe for sending a part of the washing water contained in the washing tank, and a chemical treatment sent by the chemical treatment solution sending pipe. Processing solution,
And the washing water sent by the washing water sending pipe,
, A circulating tank containing a mixed solution prepared by mixing the dialysis solution, a filter for dialysis of the mixed solution contained in the circulating tank, and separating the concentrate into a permeate and a concentrate, and a concentrate obtained by the filter. Concentrated solution sending pipe for sending the solution to the circulation tank, permeate solution sending pipe for sending the permeate obtained by the filter to the washing tank, and
And a mixed solution sending pipe for sending a mixed solution containing a concentrated solution contained in the circulation tank to the chemical conversion treatment tank. 6. The pre-coating apparatus according to claim 4, wherein the washing means has n stages (n is an integer of 2 or more), and these washing means are arranged in series. Among the flushing means arranged in series, overflow means for sending overflow water in the flushing tanks of the second to nth flushing means to the flushing tanks of the preceding flushing means are provided, and the first flushing means is provided. The overflow water in the washing tank is sent by the washing water sending pipe, and the permeated liquid sending pipe is used to obtain at least one of the washing tanks of the first to nth washing means by the filter. Coating pretreatment device, wherein the permeated liquid is sent. 7. The filter according to claim 1, wherein the filter is a nanofilter membrane,
The coating pretreatment apparatus according to any one of claims 4 to 6, wherein the pretreatment apparatus is at least one selected from the group consisting of a reverse osmosis membrane and a pressure dialysis membrane.