JP5053521B2 - Coating method - Google Patents

Description

  The present invention relates to a method for forming a coating film having a metallic appearance by depositing metallic paint on a surface to be coated in a spot shape by a sputter coating machine.

Conventionally, as a method of forming a coating film having a metallic appearance by attaching a metallic paint to a surface to be coated in spots, for example, a paint containing a metal pigment such as flake-like aluminum or stainless steel is used. It is generally known that, when used, it gives a metallic appearance to the object.
Japanese Patent Laid-Open No. 10-118558

  By the way, metallic pigments such as flake-like aluminum and stainless steel contained in the metallic paint have a problem that the color difference strongly changes depending on the orientation of the pigment in the coating film.

  That is, when the posture of the metal piece, which is the metal pigment, lies entirely on the surface of the coating film, the brightness of the metal is conspicuous and the whole becomes brighter. On the contrary, when the posture of the metal piece as a whole stands with respect to the surface of the coating film, the brightness of the metal cannot be expected and it becomes dark as a whole.

  As a means for solving this problem, as described in Japanese Patent Application Laid-Open No. 10-118558, a method of controlling the attitude of the metal pigment using an air coating machine in which the paint NV is controlled to 55 to 70%, or vice versa. Although the paint was applied with a low NV as much as possible and the metal pigment was always applied in a state of being laid down, the color was stabilized, but there was a problem that the overall appearance was uneven and the appearance was not good.

  The present invention has been made paying attention to the above-mentioned problems, and when applying an object such as an outer wall material, even when applying a metallic paint in which the pigment is oriented and the color difference is not stable, Similarly, it aims at providing the coating method which can be painted beautifully.

  In order to solve the above-mentioned problems, the coating film forming method of the present application is to atomize a water-based metallic paint by sputter coating, to increase the coating NV to 65% or more, and to apply the paint in spots on the object to be coated. It is characterized by making it.

The second coating film forming method of the present application is the lightness of the solid film (L) when the water-based metallic paint is applied at a coating plate temperature of 80 ° C. to a film thickness of 20 μm. is characterized by using a coating material in which the difference in 4.0 the following values) and the lightness of the colored layer of the coated article (L value).

  According to the method for forming a coating film of claim 1 of the present application, the coating NV is 65% or more when applied to an object by spraying the paint in a granular form, and the paint viscosity increases. The metallic resin in the metallic paint is not oriented and the color difference is stabilized.

According to the coating film forming method of claim 2 of the present application, the coating plate temperature is set to 80 ° C., the film thickness is set to 20 μm, the lightness (L value) of the solid film and the lightness (L value) of the object to be coated are the difference between the and 4.0 or less, even if uneven paint by metallic coating, unevenness obscuring visible on the surface of the stable metal appearance.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, an undercoat coating 2 that is a waterproof coating and a top coating 3 that is a colored coating are formed in advance on the surface of the outer wall substrate 1. The undercoating film 2 and the top coating film 3 are made of a coating resin mainly composed of an acrylic silicon resin, and are formed by spraying a coating material 7 in a granular form from a sputter coating gun 8 on an object to be coated.

  This granular paint contains a metallic pigment and a colored pigment. By applying the granular paint with an application NV of 65% or more in a spotted manner on the object to be coated, the viscosity of the applied paint becomes high and the metallic pigment becomes difficult to move after the application. For this reason, a coated surface with high brightness can be produced without the orientation of the metallic pigment. The coating NV value is a ratio of the paint W0 after drying with respect to the weight W1 of the paint 7 when 1 minute has passed after coating, and is obtained from (W0 / W1) × 100%.

  Further, if the difference in color difference L between the metallic paint color 7 and the top coat 3 on the surface of the object to be coated is 40 or less, even if a small amount of the metallic paint to be applied in spots is visible, the ground of the object can be seen. Since the difference in color difference between the metallic coating film and the coating film of the object is small, it appears as a stable metal surface. In addition, this method has an advantage that even if a coating unevenness occurs when the metallic paint is discharged, the unevenness is difficult to understand and the production stability is excellent.

  A plate material as an object to be used used in this embodiment is a building material and has an uneven portion. Specifically, as the object to be coated, plate-like objects used for outer parts such as outer walls, inner walls and roofs of general buildings, buildings and offices can be raised. The size is preferably about 450 mm × about 3000 mm. On these surfaces, a round shape, an acute angle, an unevenness on an acute angle, and a groove-like recess having a narrow width or a wide width are formed. These uneven shapes can be formed by a known method. As materials for these building materials, for example, ALC materials, slate, wood chip cement boards and the like are listed. When these building materials are preheated and coated in a state where the temperature is kept at 40 ° C. to 80 ° C., coating sagging at the convex portions is reduced, and the water content in the coating becomes constant. effective.

  As a spray coating machine for spraying a metallic paint, a coating machine called a sputter coating machine that can generally coat a granular pattern is suitable. The metallic paint used is a liquid paint prepared by mixing and dispersing a resin component and a metallic pigment in water.

  These may be any of room temperature drying type, room temperature curing type, and heat curing type. As the resin component, a vehicle resin such as an acrylic resin, a polyester resin, a urethane resin, or a fluororesin can be suitably used.

  Metallic pigments are pigments that form a glittering coating film, and examples include scaly aluminum, bronze, stainless steel, nickel powder, and mica-like iron oxide. These metallic pigments are suitably 0.1 to 1 μm in thickness and 1 to 50 μm in the longitudinal direction.

The ratio of the metallic pigment in the metallic paint is suitably 30 to 80 parts by weight, particularly 40 to 60 parts by weight per 100 parts by weight (solid content) of the resin component in order to express the glitter. The metallic paint can be mixed with an inorganic pigment such as titanium oxide, carbon black and iron oxide, and an organic pigment such as an azo pigment and a phthalocyanine pigment as appropriate.
[Example]

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. (1) Object to be coated The object to be coated has a groove (large concave portion) having a width of 10 mm and a depth of 3 mm covered with a colored acrylic resin. A wood chip cement board (size: 890 mm × 1500 mm × 15 mm) which was kept warm (preheated) at 40 ° C. to 80 ° C. was coated.
(2) Water-based paint Water-based paint is an acrylic resin emulsion paint. The water-based paint has a viscosity of 20 seconds / Iwata Cup (HIS) / 20 ° C. and a paint NV adjusted to 25 to 40%. The paint contains a metallic pigment mainly composed of stainless steel, and a trace amount. By using a material containing the carbon black coloring pigment, the lightness (L value) of the solid film when adjusted to a film thickness of 20 μm at a coating plate temperature of 80 ° C. is adjusted to 78.

The paint NV value is a ratio of the paint W0 after drying to the weight W of the paint before drying, and is obtained from (W0 / W) × 100%.
(3) Sputter coating machine The sputter coating machine uses a sputter coating system manufactured by Asahi Sunac Corporation, the distance from the gun tip to the coated surface is 300 mm, the spray pattern width in the longitudinal direction is 300 mm, the reciprocating speed is 40 m / min, The conveyor speed is 6 m / min, the effective reciprocating length is 2000 mm, and coating is performed at a discharge rate of 80 to 240 g / min with two coats.
[Example 1]

  In Example 1, a paint having a paint NV adjusted to 38% was prepared as the paint 7. The paint NV value is a ratio of the paint W0 after drying to the weight W2 of the paint before drying, and is obtained from (W0 / W2) × 100%. Table 1 shows the results of coating with this coating material adjusted to a discharge rate of 240 g / min with the above-described sputter coater and the plate temperature of the object to be coated adjusted to 40-80 ° C. In addition, the thing (L value) of the top coat film of the to-be-coated object at this time used the thing of 54. FIG. 2 shows a sample using the method for forming a coating film of Example 1, and black spots on the surface of the enlarged photograph indicate a metallic paint.

According to Example 1, the difference in lightness (L value) was as small as about 1.1 regardless of the difference in plate temperature before coating, and no difference in appearance was recognized. The coated NV was all 65% or more.
[Specific Example 1 ]

In this specific example 1 , the paint 7 was prepared by adjusting the paint NV to 26%. Table 2 shows the results of coating with the coating material 7 adjusted to a discharge rate of 240 g / min with the above-described sputter coater and the plate temperature of the object to be coated adjusted to 40-80 ° C. In addition , the thing (54 value) of the brightness (L value) of the top coat film of the to-be-coated object at this time was used.

[Comparative Example 1]
In Comparative Example 1, coating was performed in the same manner as in Specific Example 1 except that the plate temperature before coating was 40 ° C. and 60 ° C. The results are shown in Table 3.
In Comparative Example 1, compared with Example 1, the difference in lightness (L value) due to the difference in the plate temperature before coating was as large as 10.9, so a large difference in appearance was recognized. . The coating NV is 65% or less.
[Example 2]

In Example 2, a paint whose paint NV is adjusted to 28% is prepared as the paint 7. Table 4 shows the results of coating with the coating material adjusted to a discharge rate of 80 g / min with the above-described sputter coater and the plate temperature of the object to be coated adjusted to 40-80 ° C. In addition, the thing (L value) of the top coat film of the to-be-coated object at this time used the thing of 80.

In Example 2, the difference in brightness (L value) was as small as about 0.4 regardless of the difference in plate temperature before coating, and no difference in appearance was recognized. The coated NV was all 65% or more. When this coating film was closely observed, the coating 7 did not completely cover the top coating film of the object to be coated, but the difference in lightness (L value) between the coating material 7 and the top coating film of the coating material was 4. There was no sense of incongruity because it was small as below.
[Specific Example 2 ]

In this specific example 2 , the paint 7 is prepared by adjusting the paint NV to 28%. Table 5 shows the results of coating with the coating material adjusted to a discharge rate of 80 g / min with the above-described sputter coater and the plate temperature of the object to be coated adjusted to 40 to 80 ° C. In addition, the thing (L value) of the top coat film of the to-be-coated object at this time used the thing of 54.

In this specific example 2 , the difference in brightness (L value) was about 6.0 due to the difference in the plate temperature before coating, and a large difference in appearance was recognized. The coated NV was all 65% or more. When this coating film was observed in proximity, the coating material 7 did not completely cover the top coating film of the object to be coated.
When the coating plate temperature is around 80 ° C., the lightness (L value) close to the lightness value 54 of the top coat film is 54.3.
Therefore, a lightness L close to the value 80 of the lightness L of the top coat paint sheet temperature is 80 ° C. as shown in Table 4 of Example 2 80. 3 is obtained, and the lightness (L value) of the solid film and the lightness (L value) of the colored layer of the object to be coated when the aqueous metallic paint is applied at a coating plate temperature of 80 ° C. with a film thickness of 20 μm. The differences are both about 0.3 and 4.0 or less.

Explanatory drawing of the sputter coating method concerning embodiment of this invention. The sample of Example 1, and the enlarged photograph of the surface.

Explanation of symbols

1 Equipment 2 Undercoat 3 Topcoat 4 Granular Coating 5 Metallic Pigment 6 Colored Pigment 7 Paint 8 Spatter Paint Gun

Claims (2)

  A method of forming a coating film, characterized in that a water-based metallic paint is atomized by sputter coating, the coating NV is made 65% or more, and the paint is applied to an object to be spotted. 2. The coating film forming method according to claim 1, wherein the lightness (L value) of the solid film and the lightness (L value) of the colored layer of the coating object when the aqueous metallic paint is applied at a coating plate temperature of 80 ° C. to a film thickness of 20 μm. The coating film formation method characterized by using the paint which made the difference with 4.0 or less 4.0 .