JP3165521B2 - Washing method of electrodeposition coating - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrodeposition coating material physically adhered to the surface of an object to be electrodeposition coated and a method of washing the electrodeposition coating water for removing impurities.

[0002]

2. Description of the Related Art FIG. 2 is a view for explaining a proposed coating process. The article 1 is transferred over the entire process by a transfer means (not shown).

[0003] An object 1 to be coated is immersed in an electrodeposition tank 2 filled with an electrodeposition coating material 2a, and electrodeposition coating is performed. Next, UF
(Ultra Filtration System) Water washing is performed. The UF washing step includes UF first to third washing steps.

In the UF first washing step, the UF washing liquid 3 is sprayed onto the work 1 from a first tank 4 filled with the UF washing liquid 3 and a plurality of nozzles 7 connected via a pump 5 and a pipe 6. I do. Next, UF second washing is performed. In this step, similarly to the UF first washing, the second tank 9 filled with the UF washing liquid 8 and the plurality of nozzles 12 connected via the pump 10 and the pipe 11 are provided. UF cleaning liquid 8 is sprayed on the article 1 to be coated. Next, the UF third washing is performed. In this step, the article 1 is immersed in the immersion tank 14 filled with the UF cleaning liquid 13.

[0005] U discharged from the UF first to third washing steps
The F cleaning liquid is separated from the solid content in the electrodeposition coating material by using an ultrafiltration membrane, water, a solvent, a neutralizing agent, ions, and the like, and is used in circulation. Further, a liquid obtained by removing a solid content in the electrodeposition paint 2a from the electrodeposition paint 2a in the electrodeposition paint 2 using an ultrafiltration membrane is supplied as a UF cleaning liquid. The solid content in the electrodeposition paint collected here is
It is returned to the electrodeposition tank 2.

Next, washing with industrial water is performed. The rinsing step using industrial water includes first to third rinsing steps for industrial water. In the first industrial water washing step, the article 1 is immersed in an immersion tank 16a filled with industrial water 15. The industrial water 15 is filled in the third tank 16 and the pump 1
7 feeds into the immersion tank 16a via a conduit 18.

In the second industrial water washing step, the industrial water 15 is supplied from the third tank 16 and the plurality of nozzles 21 connected via a pump 19 and a pipe 20 to the substrate 1.
Sprayed on. In the third industrial water washing step, a fourth tank 23 filled with industrial water 22 and a pump 24
And a plurality of nozzles 2 connected via a conduit 25
From 6, industrial water 22 is sprayed on the article 1. 4th
The tank 23 and the third tank 16 are connected by a pipe 27, and the overflow of the industrial water 22 supplied to the fourth tank 23 is supplied to the third tank 16.

Next, cleaning with pure water is performed through a nozzle 28, and baking is performed by a baking furnace 29.

[0009]

When the object 1 is transferred from the immersion tank 2 to the first UF washing step after the electrodeposition coating is completed, a physical coating is formed on the coating film formed on the object 1. The electrodeposited paint 2a that has adhered is taken out of the electrodeposition tank 2. Although the electrodeposition paint 2a adhering to the article 1 is reduced by spray washing in the UF first and second washing steps, if the article 1 is immersed in the immersion tank 14, UF
The concentration of the electrodeposition paint 2a in the cleaning liquid is 0.8%.

When the article 1 is transported from the UF third washing step to the industrial water first washing step, if the article 1 is a car body, it is usually in a 10 liter immersion tank 14 per one. U
The F cleaning liquid 13 is brought into the immersion tank 16a of the first industrial water washing step.

The concentration of the electrodeposition paint 2a contained in the industrial water 15 in the immersion tank 16a is determined in consideration of the secondary dripping property of the coating film.
Desirably, it is 400 ppm or less. When one article to be coated 1 is brought into the immersion tank 16, 10 liters of the 0.8% electrodeposition paint 2a is brought in.
It is necessary to add industrial water 15 so that 0.8% of industrial water becomes 400 ppm. At this time, the amount of the industrial water 15 necessary for diluting to 400 ppm is 200 liters per unit.

For this reason, every time one article to be coated 1 is brought into the immersion tank 16a for performing the first industrial water washing, 200 liters of industrial water 15 must be supplied.
There is a problem that the amount of used is large and costs are high.

It is an object of the present invention to provide a method for washing electrodeposition coating, which can reduce the amount of industrial water used without lowering secondary sagging.

[0014]

SUMMARY OF THE INVENTION The present invention relates to a method for washing an electrodeposited article with water before the baking is performed. The first to remove the coating material, collect the electrodeposition coating material, and perform UF water washing.
A water-washing step, a second water-washing step in which the electrodeposition paint remaining in the first water-washing step is removed by spray watering in which industrial water is sprayed from a nozzle 62, and an object to be coated after the second water-washing step is placed in an immersion tank 46a. A third rinsing step of removing impurities remaining on the surface of the object to be coated, including a step of immersing in the industrial water, and adjusting the industrial water in the immersion tank 46a to a concentration of the electrodeposition paint of 400 ppm or less. The industrial water is supplied to the nozzle 62. In the present invention, the third washing step may include:
The industrial water supplied from the first tank 46 by the first pump 49 is sprayed from the third nozzle 51 for the third rinsing step and washed, and then the industrial water supplied from the second tank 53 by the second pump 54. Is sprayed from the second nozzle 56 for the third rinsing step to be washed with water, and the second tank 53
And the industrial water overflowed in the second tank 53 is supplied from a pipe 57 to the first tank 46, and the industrial water in the first tank 46 is supplied to the immersion tank 46 a by a third pump 47. The industrial water supplied and sprayed from the nozzle 62 is drained after spray washing.

[0015]

According to the present invention, in the electrodeposition coating rinsing method for removing the electrodeposition paint and impurities physically adhered to the surface of the object to be electrodeposited, the first rinsing step includes the steps of: The electrodeposition paint physically adhered to the substrate is removed, the electrodeposition paint is recovered, the electrodeposition paint remaining in the first water washing step is removed by spraying in the second water washing step, and the surface of the article to be coated is removed in the third water washing step. The remaining impurities are removed. The electrodeposition paint remaining in the first rinsing step is removed by spraying in the second rinsing step.
The amount brought into the rinsing step is reduced, and rinsing can be easily performed in the third rinsing step. In particular, according to the present invention, after the first rinsing step of performing UF rinsing, the industrial water sprayed from the nozzle 62 in the second rinsing step of performing spray rinsing is the industrial water of the immersion tank 46a included in the third rinsing step. This industrial water is used when the concentration of the electrodeposition paint is 400 p.
pm or less, so that secondary sagging of the coating film during baking can be reliably prevented. According to the present invention, industrial water is supplied to the second tank 53, and industrial water overflowing from the second tank 53 is supplied to the first tank 46 from the pipe 57, and the first and second tanks are supplied. 46, 53 industrial water is the third
Rinsing is performed from the first and second nozzles 51 and 56 for the rinsing step to remove impurities remaining on the surface of the object to be coated.
Is discharged after the spray water washing in the second water washing step.

[0016]

FIG. 1 is a view for explaining a coating process according to an embodiment of the present invention. The article 31 is transferred over the entire process by a transfer means (not shown).

The object 31 is immersed in an electrodeposition tank 32 filled with an electrodeposition paint 32a, and is subjected to electrodeposition coating. Next, UF (Ultra Filtration System) washing is performed. UF
The washing step includes UF first to third washing steps.

In the UF first washing step, a first tank 34 filled with a UF washing liquid 33, a pump 35 and a pipe 3
The UF cleaning liquid 33 is sprayed onto the object 31 from a plurality of nozzles 37 connected through the nozzle 6. Next, UF second rinsing is performed. In this step, similarly to the UF first rinsing, a second tank 39 filled with the UF cleaning liquid 38 and a plurality of nozzles 42 connected via a pump 40 and a pipe 41 are provided. To U
The F cleaning liquid 38 is sprayed on the object 31. Next, a UF third washing step is performed. In this step, the UF cleaning liquid 43
The article 31 is immersed in the immersion tank 44 filled with.

U discharged from the first to third UF washing steps
The F cleaning liquid is separated from the solid content water in the electrodeposition paint using a ultrafiltration membrane, a solvent, a neutralizing agent, and ions, and is used in circulation.
Further, a liquid obtained by removing the solid content in the electrodeposition paint 32a from the electrodeposition paint 32a in the electrodeposition paint 32 using an ultrafiltration membrane is supplied as a UF cleaning liquid. The solid content in the electrodeposition paint collected here is returned to the electrodeposition tank 32.

In this embodiment, after the UF third washing, the second washing is performed.
As a water washing step, spray water washing is performed. A plurality of nozzles 62 are connected via a pump 60 and a pipe 61 to the bottom surface of an immersion tank 46a filled with industrial water 45 used for the first rinsing of industrial water to be described later. 45 is sprayed onto the object 31 from the nozzle 62.

Next, washing with industrial water is performed. The rinsing step using industrial water includes first to third rinsing steps for industrial water. In the first industrial water washing step, the article 31 is immersed in the immersion tank 46a filled with the industrial water 45. The industrial water 45 is filled in the third tank 46 and the pump 4
7 through a conduit 48 to the immersion tank 46a.

In the industrial water second rinsing step, the industrial water 45 is supplied from the third tank 46 and the plurality of nozzles 51 connected via the pump 49 and the pipe 50 to the substrate 3.
Spray on 1. In the third industrial water washing step, the fourth tank 53 filled with the industrial water 52 and the pump 5
Industrial water 52 is sprayed onto the object 31 from a plurality of nozzles 56 connected via the pipe 4 and the pipe 55.
The fourth tank 53 and the third tank 46 are connected by a pipe 57, and the overflow of the industrial water 52 supplied to the fourth tank 53 is supplied to the third tank 46.

Next, cleaning with pure water is performed through a nozzle 58, and baking is performed by a baking furnace 59.

As shown in FIG. 1, the fourth tank 53 is supplied with industrial water. The industrial water sprayed from the nozzle 62 is drained after the object 31 is spray-washed. As described above, according to this embodiment, the UF third rinsing step using the immersion tank 44 and the industrial water first rinsing step using the immersion tank 46a are performed.
The spray water washing process by the nozzle 62 is performed between the water washing process. In the spray water washing, the industrial water 45 filled in the immersion tank 46a used for the first industrial water washing is used as the spray water by the nozzle 62. By introducing the spray rinsing after the UF third rinsing, conventionally, the UF cleaning liquid containing the 0.8% -concentration electrodeposition paint is brought into the 10-liter immersion tank 46a together with the body to be coated 31 per vehicle. The concentration is 400 ppm
200 liters of industrial water 18 was required to achieve this, whereas the concentration of the electrodeposition paint on the surface of the object 31 could be reduced to 0.4% by spray washing with the nozzle 62. UF brought into immersion tank 46a
The cleaning liquid is 10 liters of industrial water containing 0.4% of electrodeposition paint per one unit. To dilute this to 400 ppm, 100 liters of industrial water per unit is required. This is a half of the conventional amount, and the usage amount of the industrial water 45 can be reduced. The industrial water used in the second rinsing step uses a part of the industrial water drained to make the concentration of the electrodeposition paint in the immersion tank 46a 400 ppm.

Further, not only can the amount of the industrial water 45 used be reduced, but also the concentration of the electrodeposition paint in the immersion tank 46a can be maintained at 400 ppm or less. It is possible to carry out a water washing method of electrodeposition coating that requires a good coating film.

[0026]

According to the present invention, the electrodeposition paint remaining in the first rinsing step is removed by spraying in the second rinsing step. The amount brought into the process is reduced, and the amount of industrial water required for the third rinsing process can be reduced without impairing secondary sagging,
A good coating film can be easily obtained. In particular, according to the present invention, the industrial water sprayed from the nozzle 62 used for spray rinsing in the second rinsing step is supplied to the immersion tank 46a provided in the third rinsing step for removing impurities.
Of industrial water is used, the concentration of the electrodeposition paint is adjusted to 400 ppm or less, and therefore, secondary sagging of the coating film during baking is reliably prevented. According to the present invention, in the third washing step, industrial water is supplied to the second tank 53, and the overflowed industrial water is supplied from the pipe 57 to the first tank 53.
The first and second tanks 46, 5
3 is the first and second nozzles 5 for the third washing step.
The object to be coated is washed by spraying from the nozzles 1 and 56, and the industrial water in the first tank 46 is supplied to the immersion tank 46a.
The industrial water sprayed from 2 is drained after washing with spray water, and drained in this manner, so that the immersion tank 4
It is possible to prevent the concentration of the electrodeposition coating material 6a from increasing beyond 400 ppm.

[Brief description of the drawings]

FIG. 1 is a view for explaining a painting process according to one embodiment of the present invention.

FIG. 2 illustrates a proposed painting process.

[Explanation of symbols]

 31 Coating object 45 Industrial water 46 Third tank 46a Immersion tank 60 Pump 61 Pipe line 62 Nozzle

──────────────────────────────────────────────────続 き Continuing from the front page (72) Nobuo Kuranami 6-10-73 Minamitsukaguchi-cho, Amagasaki City, Hyogo Prefecture Inside Shinto Paint Co., Ltd. (56) References Real Opening Showa 60-60461 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) C25D 13/00

Claims (2)

(57) [Claims] An electrodeposition coating method for washing an electrodeposited article with water before baking is performed, wherein the electrodeposition paint physically attached to the surface of the article is removed. A first rinsing step of collecting paint and performing UF rinsing, a second rinsing step of removing the electrodeposition paint remaining in the first rinsing step by spray rinsing by spraying industrial water from a nozzle 62, and a second rinsing step And a third washing step of removing impurities remaining on the surface of the article to be coated, including a step of immersing the article to be coated in the industrial water in the immersion tank 46a, and a step of rinsing the industrial water in the immersion tank 46a. A method for washing the electrodeposition paint by adjusting the concentration of the electrodeposition paint to 400 ppm or less and supplying the industrial water to the nozzle 62. 2. The third rinsing step is to spray industrial water supplied from the first tank 46 by the first pump 49 from the first nozzle 51 for the third rinsing step, and then to rinse the water. The industrial water supplied from the second pump 54 is sprayed from the second nozzle 56 for the third rinsing step and washed with water, the industrial water is supplied to the second tank 53, and the industrial water overflowed in the second tank 53. Is supplied to the first tank 46 from a pipe line 57, and the industrial water in the first tank 46 is supplied to the immersion tank 46a by a third pump 47. The industrial water sprayed from the nozzle 62 is washed with spray water. 2. The method according to claim 1, wherein the water is drained.