JPH03213175A - Method and apparatus for continuously applying intermediate paint - Google Patents

Abstract

PURPOSE:To reduce an increase in painting cost by continuously mixing two or more kinds of intermediate paints to prepare mixed intermediate paint whose brightness is approximate to that of topcoating paint. CONSTITUTION:Intermediate paints sent under pressure by pumps 13, 14 passed through pipes 15, 16 and three-way valves 17, 18 and a predetermined amount of the intermediate paints are allowed to flow to a pipeline 19 through the three-way valves 17, 18. The excessive intermediate paints are returned to intermediate paint storage tanks 11, 12 through pipelines 20, 21. The intermediate paints allowed to flow through the pipeline 19 are mixed by a mixer 22 and the intermediate paint mixture is emitted from a nozzle 23 to be subjected to painting. By this method, paint control cost can be reduced to a large extent.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a continuous coating method and apparatus for intermediate coating paint, and more specifically to a method and apparatus for continuously applying a desired intermediate coating paint according to top coating paint. Regarding equipment.

<Prior Art> In recent years, colors with high saturation and transparent hues have become preferred for top coat paints for automobiles.

However, such paint has a hiding power of 50 to 1 for boat fishing.
The film thickness is as low as 00μm, which is less than the normal film thickness of top coat paint (30~50μm).
In m), it is difficult to completely hide the intermediate coating color,
There is a problem in that the bright colors inherent to top coat paints cannot be obtained. Furthermore, if a coating is applied to a film thickness of 50 μm or more for concealment, there is a problem that sagging, wrinkles, etc. may occur. Under these circumstances, research is underway to bring the color of the top coat closer to the original color even when the top coat cannot completely hide the color of the intermediate coat. Examples of such methods include applying an intermediate coat with a hue similar to that of the top coat, and applying an intermediate coat with a brightness similar to that of the top coat (Japanese Patent Laid-Open No. 58-1
66962).

<Problems to be Solved by the Invention> However, in these methods, it is necessary to prepare several types of intermediate coating paint depending on the hue and brightness of the top coating paint, but in order to prepare the intermediate coating paint, it is necessary to prepare each type of intermediate coating paint. It is necessary to install a paint circulation supply system, prepare paint, manage paint, and manage the painting process. Therefore, since these methods use many types of intermediate coating paints, paint management and paint process management are complicated, and equipment costs and paint costs are required, resulting in an increase in painting costs.

<Means for Solving the Problems> According to the present invention, two or more types of intermediate coating paints having different brightnesses each having a difference in brightness (ΔL) of 10 or more are prepared.

The mixing ratio is set so that the brightness of the top coat to be applied is almost similar to the brightness of the two or more intermediate paints, and , comprising the steps of continuously mixing two or more types of intermediate coating paints at the above-mentioned mixing ratio to prepare a mixed intermediate coating paint having a brightness close to that of the top coating paint, and discharging the mixed intermediate coating paint. A continuous coating method for intermediate coating paint is provided.

Further, according to the present invention, there is provided a plurality of intermediate coating paint storage devices for respectively storing two or more types of intermediate coating paints having different brightnesses with a difference in brightness (ΔL) of 10 or more, and a plurality of intermediate coating paints for storing the two or more types of intermediate coating paints in a continuous manner. a mixing device for mixing each intermediate coating paint from the intermediate coating paint storage device to the mixing device at a ratio such that the brightness of the top coating paint to be applied and the brightness of the mixed intermediate coating paint of the two or more types are approximately similar; There is provided a continuous coating device for intermediate coating paint, comprising: a supply device that continuously supplies; and a nozzle device that discharges the intermediate coating mixture mixed in the mixing device.

The present invention will be explained in more detail below.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the accompanying drawings, a continuous intermediate coating paint coating apparatus 10 of the present invention is schematically shown. Intermediate paint tanks 11 and 12 store intermediate paints having different brightnesses, each having a difference in brightness (ΔL) of 10 or more. In the illustrated example, intermediate coating paint tanks 11 and 12
Although an example in which two are provided is shown, three or more types of intermediate coating paints may be used. In either case, the difference in brightness between each intermediate coating must be 10 or more in terms of L value. If the difference in brightness is less than 10, even if the mixing ratio is changed, the brightness range of the mixed intermediate coating paint obtained will be narrow, and it will be difficult to approximate the brightness of the various top coat paints to be applied, so it cannot be used.

As the intermediate coating, known intermediate coatings such as oil-free polyester resin paints, alkyd resin paints, acrylic resin paints, and epoxy resin paints can be used without any particular restrictions.

In the present invention, on the plan to apply! ! 2! The pump 13 is operated so that the brightness of the paint and the brightness of the mixed intermediate paint are approximately approximated.
．． 14 flow rates are set respectively. Setting the brightness to be approximately similar means that there is virtually no difference visually between the two. To set the flow rate of pumps 13 and 14, test the mixing ratio in advance with a patch method,
It can be easily determined by measuring the color difference with the top coat. As the pumps 13 and 14, any type of pump may be used as long as it is capable of pumping the intermediate coating material, such as an air pressure-feeding type %-type rose pump or a snake pump.

The intermediate coating paints pumped by pumps 13 and 14 are each pipe 1.
5.16 and to three-way valves 17.18, and at each three-way valve 17.18, a predetermined amount of intermediate coating paint is passed through pipes 198, and excess intermediate coating paint is stored through pipes 20 and 21. Returned to tank 11.12.

Next, the intermediate coating paint distributed through the pipe line 19 is mixed in the mixer 22. As the mixer, various mixers such as a rotary mixer and a static mixer can be used. The mixed intermediate coating paint mixed at a predetermined ratio is then discharged from the nozzle 23. The mixed intermediate coating paint discharged in this way is used for air atomization painting and air atomization electrostatic painting.

The coating can be applied using any coating method such as rotary atomization electrostatic coating, airless atomization electrostatic coating, or airless atomization electrostatic coating.

<Effects of the Invention> The coating method and apparatus of the present invention have the following advantages over conventional intermediate coatings.

■ An intermediate coating color of any brightness can be obtained continuously using two or more types of paint and two or more paint circulation systems. This makes it possible to significantly reduce the costs associated with the many types of intermediate paints and paint circulation systems that were conventionally required, as well as paint management costs.

■ In order to obtain the original bright color with a normal topcoat film thickness by applying a highly saturated topcoat with poor hiding properties, it is necessary to apply various types of intermediate paints that match the lightness of the topcoat. , This is a major bottleneck when designing the color of top coat paints. However, according to the present invention, it is possible to easily obtain a wide variety of intermediate coating colors of arbitrary lightness.
It is easy to obtain a color tone with a color difference of 0.5 or less in terms of E value between the intermediate coat and the top coat, which greatly expands the degree of freedom in color design for automotive top coats and meets a wide range of customer needs. becomes possible.

(2) Even if the topcoat film has an incompletely concealed film thickness, the color difference from the completely concealed part can be reduced to 0.5 or less in terms of ΔE value.

<Examples> Hereinafter, the present invention will be explained in more detail with reference to Reference Examples and Examples. Note that % indicates weight %.

The intermediate coating was adjusted to a P/B ratio (pigment/resin weight ratio) of 1.0 using titanium oxide. Oil-free polyester melamine resin paint A with an L value of 94 (product name: ``Hiepico Nα''
1 Sealer White", oil-free polyester melamine resin paint B with an L value of 4.0 adjusted to a P/B ratio of 0.087 with Nippon Oil & Fats [manufactured by Nihon Yushi Co., Ltd.] and carbon black (product name "Hiepico Nα1 Sealer Black" 1 Japan) (manufactured by Oil & Fat ■) was used.

1 Consideration 1- Intermediate coating paint A with an L value of 94 was mixed at a ratio of 98.75% and intermediate coating paint B with an L value of 4 was mixed at a ratio of 1.25%. Table of painting results = 1
Shown below.

Reference Examples 2 to 12 The mixing ratio of intermediate coating paint A with an L value of 94 and intermediate coating paint B with an L value of 4 was changed as shown in Table 1, and the obtained L values are shown in Table 1.

As a result, as shown in Table 1, it was found that an intermediate coating film of any brightness could be obtained by changing the mixing ratio of two types of paints having different brightnesses.

(Margins below) - Nijiyoyo JL example - Red paint with hiding power of 65 μm and lightness of 42 was applied on top of the intermediate coating paints obtained in Reference Examples 1 and 4.8, which had different lightnesses, with varying film thickness levels. Completely concealed area (top coat 65μm)
(8E) As is clear from these results, in a paint system that matches the brightness of the intermediate and top coats, there is a ΔE of 0.5 that does not cause any discomfort to the naked eye even when it is not completely concealed. It turns out that the following is true.

That is, when the intermediate coatings obtained from Reference Examples 1 and 8 were applied and then the topcoat was applied to a film thickness of 25 to 45 μm, the color difference from the completely concealed topcoat (65 μm) was 0. On the other hand, when applying the intermediate coating of Reference Example 4, the color difference is smaller than that of Reference Examples 1 and 8, and especially when the top coat film thickness is 45 μm, it is 0.5 or less. I understand.

[Brief explanation of drawings]

The accompanying drawings are schematic diagrams showing a continuous coating apparatus for intermediate coating paint according to the present invention. 11.12... Intermediate paint tank, 13.14... Pump, 17.18... Three-way valve, 22... Mixer 23
··nozzle.

Claims (1)

[Scope of Claims] 1) Two or more types of intermediate coat paints having different brightnesses with a lightness difference (ΔL) of 10 or more are prepared, and the brightness of the top coat paint to be applied is different from the brightness of the two or more types of intermediate coat paints. The mixing ratio is set to be approximately similar, and the two or more types of intermediate coating paints are continuously mixed at the mixing ratio to prepare a mixed intermediate coating paint with a brightness that approximates the brightness of the top coating paint, and the mixed intermediate coating paint is prepared. A continuous coating method for intermediate coating paint, characterized in that it includes each step of discharging. 2) A plurality of intermediate coating paint storage devices for respectively storing two or more types of intermediate coating paints having different lightness with a lightness difference (ΔL) of 10 or more, and a plurality of intermediate coating paint storage devices for continuously mixing the two or more types of intermediate coating paints. a mixing device, and a supply that continuously supplies each intermediate coating paint from the intermediate coating paint storage device to the mixing device at a ratio such that the brightness of the topcoat paint to be applied and the brightness of the mixed intermediate coating paint of the two or more types are approximately similar. 1. A continuous coating device for intermediate coating paint, comprising: a device; and a nozzle device for discharging intermediate coating paint mixed in the mixing device.