How to paint resin parts

Abstract

To provide a method for coating a resin member which can easily provide masking with a simple facility and enables formation of a basis material color region with excellent appearance quality, when the basis material color region and a color region are provided in a resin member.SOLUTION: A method for coating a resin member 10, which includes providing a masking 14 in a part 17 where a basis material color is to be left of a resin member 10, subjecting a part 16 to be colored of the resin member 10 to primer treatment and coloring the part 16 by coating a coloring coating composed of an aqueous coating material, removing the masking 14, and forming a basis material color region 11 and a color region 12, cures an aqueous coating material to the part 17 where the basis material color is to be left and cures the aqueous coating material, and thereby provides the masking 14 that is peelably brought into close contact with a basis material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a method for coating a resin member, which forms a base color region and a colored region in the resin member. [Background technology]

[0002] 2. Description of the Related Art Conventionally, a method for painting a resin member is known in which a base color region and a colored region are formed by painting the resin member while leaving a portion of the base color unpainted. Generally, when painting a surface while leaving only a portion of the base color intact, the areas where the base color is to be formed are first covered with a masking sheet or masking tape, and then a colored paint is applied to the remaining areas and allowed to harden.

[0003] Patent Document 1 proposes covering tiles with a color masking paint to prevent grout from adhering to the tiles. This document states that the color masking paint can be applied to various objects to be coated. Patent Document 2 proposes an easy-to-peel inspection paint that can be easily peeled off from the surface of the object to be inspected as an inspection paint for detecting changes in the physical quantity of the object to be inspected. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2015-232099 A [Patent Document 2] JP 2018-62594 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, with conventional masking, when painting a resin component while leaving its base color intact, it was necessary to place masking sheets, masking tape, etc. in the designated positions, which was time-consuming. Furthermore, if a masking is formed using a peelable paint as in Patent Documents 1 and 2, not only is it necessary to prepare expensive peelable paint, but it is also necessary to prepare separate equipment for applying the peelable paint, which requires time and effort for preparation and requires the addition or modification of equipment, making the equipment more complicated.

[0006] Therefore, the present invention aims to provide a method for painting a resin part, which allows masking to be easily applied using simple equipment when providing a base color area and a colored area on the resin part, and which enables the base color area to be formed with excellent appearance quality. [Means for solving the problem]

[0007] In order to achieve the above object, the present invention provides a method for coating a resin member, comprising the steps of: providing a masking on a portion of the resin member where the base color is to be left; primer-treating the portion of the resin member where the color is to be colored; coloring the portion with a coloring paint made of a water-based paint; and removing the masking to form a base color region and a colored region. Same as coloring paint to form colored areas By applying water-based paint and curing it, the base material color area A masking is provided in a peelable manner and adhered to the surface, and a colored paint is applied to the surface.

[0008] In the method for coating a resin member of the present invention, the area to be colored is covered with a masking tool, and the area to be left with the base color is masked by applying a water-based paint. Preferably, a clear paint is applied onto the layer of colored paint, cured, and then the masking is peeled off. Effect of the Invention

[0009] According to the method for coating a resin member of the present invention, a mask is provided on the portion of the resin member where the base color is to be left, the portion to be colored is primer-treated, and the portion is colored with a coloring paint made of a water-based paint, thereby forming a base color region and a colored region. At this time, a water-based paint is applied to the portion where the base color is to be left and cured, thereby providing a masking that is releasably adhered to the base. In order to provide a mask on the portion where the base color is to be left, a water-based paint similar to the coloring paint applied to the portion where the base color is to be left can be used, and the same coating equipment can be used. This eliminates the need to prepare separate paint or equipment for the masking, and the masking can be easily provided with simple preparation.

[0010] Moreover, since the water-based paint is applied to the area to be colored to provide a masking, the paint adheres well to the base material, and no gaps or peeling occurs due to pressure or the like when the colored paint is applied, and the colored paint can be reliably prevented from adhering to areas where the base color is to be retained. There is also little risk of the base material of the resin member being deteriorated, as with solvent-based paints. This makes it possible to ensure a high level of appearance quality in the base color area. Therefore, according to the present invention, a method for painting a resin member can be provided that, when providing a base color area and a colored area on the resin member, can easily provide a masking with simple equipment and can form a base color area with excellent appearance quality. [Brief description of the drawings]

[0011] [Figure 1] 1(a) to 1(d) are diagrams illustrating a painting process according to an embodiment of the present invention. [Diagram 2] 1(a) to (e) are diagrams illustrating the painting process according to an embodiment of the present invention from FIG. 1(d) onward. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, a coating method for a resin member according to an embodiment of the present invention will be described in detail with reference to the drawings. The object to be coated in the method for coating a resin member of this embodiment is various resin members formed into a flat or three-dimensional shape from resin, and can be applied to, for example, the bodies and exterior panels of automobiles and motorcycles, the exterior bodies of electrical products, etc.

[0013] Examples of the resin constituting the resin member include thermoplastic resins such as polypropylene resin, polyamide resin, and polyurethane resin, and the above resins reinforced with fillers.

[0014] In this embodiment, an exterior part such as an automobile bumper made of polypropylene reinforced with a filler will be described as an example. The resin member 10 is molded into an appropriate three-dimensional shape. (e) As shown in FIG. 1, a base color region 11 in which the base of the resin member 10 is exposed is provided on a portion of the outer surface exposed to the outside, and a colored region 12 colored with a coloring paint is provided on the remaining portion, presenting a two-tone painted appearance. The base color region 11 and the colored region 12 are formed adjacent to each other with a parting 13.

[0015] In this embodiment, the paint used to paint the resin member 10 is a generally used, inexpensive water-based paint. The water-based paint is a paint in which a film-forming resin component, a hardener, a pigment, various additive components added as required, and the like are dispersed or dissolved in a medium made of an aqueous liquid such as water.

[0016] As the resin component, various resins that are used as resin components of water-based paints are used, and examples thereof include at least one type selected from acrylic resins, vinyl resins, polyester resins, alkyd resins, and urethane resins, and resins having, as functional groups, hydroxyl groups, carboxyl groups, silicon-containing groups, epoxy groups, and isocyanate groups which may be blocked.

[0017] Examples of the curing agent include melamine resins, urea resins, polyisocyanate compounds which may be blocked, carboxyl group-containing compounds, and epoxy group-containing compounds which react with the functional groups in the resin component.

[0018] Examples of pigments include black pigments such as carbon black, acetylene black, lamp black, bone black, graphite, black iron oxide (iron tetroxide), black titanium oxide, copper manganese black, copper chrome black, cobalt black, cyanine black, and aniline black; blue pigments such as phthalocyanine-based, indanthrone-based, and indigo-based pigments; red pigments such as azo-based, diketopyrrolopyrrole-based, perylene-based, perinone-based, and iron oxide; and white pigments such as titanium oxide.

[0019] Examples of additives that may be added as necessary include various additives such as a viscosity imparting agent, a flow control agent, a light stabilizer, an ultraviolet absorber, a body pigment, and a pigment dispersant.

[0020] As the clear coating to be applied to the coating film formed by this aqueous coating, any known coating can be used as appropriate. For example, a coating in which an acrylic resin, a polyester resin, an alkyd resin, a urethane resin, an epoxy resin, or the like, a crosslinking agent such as a blocked polyisocyanate, a melamine resin, or a urea resin, and other additives are dissolved or dispersed in a medium such as an aqueous liquid can be used.

[0021] When such water-based paint is applied directly to the surface of the resin that constitutes the resin component as described above and cured to form a coating film, it is possible to form a coating film in a peelable, adherent state without dissolving the resin surface and exerting an anchor effect, and since there is no intermolecular attraction between the resin surface and the water-based paint. Furthermore, if a primer paint containing a chlorinated polyolefin resin is applied as a primer treatment to the surface of the resin constituting the resin member, and then a water-based paint is applied to form a coating film, the coating film can be fixed to the surface of the resin member 10.

[0022] To paint the resin member 10 using the above-mentioned water-based paint by the painting method of this embodiment, as shown in Figures 1(a) to (d), the water-based paint is applied to a portion 17 of the resin member 10 where the base color of the resin member 10 is to be retained and cured, thereby providing a masking 14 removably adhered to the base of the resin member 10. Next, as shown in Figures 2(a) to (c), a colored coating layer 18 and a clear coating layer 19 are formed on a portion 16 of the resin member 10 where the base color of the resin member 10 is to be retained, and then each is cured. Thereafter, as shown in Figures 2(d) to (e), the masking 14 is removed to form a base color region 11 and a colored region 12 on the outer surface of the resin member 10.

[0023] To provide a masking 14 on a portion 17 of the resin member 10 where the base color is to be retained, first, as shown in Fig. 1(a), the portion 16 of the resin member 10 to be colored is covered with a preformed masking jig 21. The masking jig 21 has a shape corresponding to the portion 16 to be colored, and by placing it in a predetermined position, the portion 16 to be colored can be covered.

[0024] After the masking jig 21 is placed in a predetermined position, a water-based paint is applied to the portion 17 where the base color is to be left, to form a masking coating layer 22, as shown in FIG. 1(b). The water-based paint used to form the masking 14 can be any of the water-based paints described above, but in this embodiment, it is possible to use a paint that has the same components, concentration, and various physical properties as the paint used to form the colored region 12 described below, that is, the same paint as the colored region 12. Furthermore, a white water-based paint that uses a white pigment such as titanium oxide as the pigment is preferable because it is inexpensive.

[0025] To apply the water-based paint for forming such masking 14 to the area 17 where the base color is to be left, a painting facility for forming the colored area 12 described below can be used. For example, the water-based paint can be sprayed and applied using a nozzle in a painting booth where the temperature and humidity are controlled. In this case, since it is only necessary to cover the area 17 where the base color is to be left with the masking 14, it is also possible to reduce overdust other than the area 17 where the base color is to be left by increasing the average particle size of the paint particles to be sprayed.

[0026] After forming the masking coating layer 22, the masking jig 21 is removed as shown in Fig. 1(c). Although the water-based paint is still attached to the masking jig 21, it can be easily removed by washing with water because it is not yet cured. Therefore, the masking jig 21 can be used repeatedly. Thereafter, as shown in FIG. 1(d), the masking coating layer 22 is dried and hardened by heating at a predetermined temperature, thereby providing a peelable masking 14 in close contact with the base material in the area 17 where the base color is to be retained.

[0027] Next, the area 16 to be colored is colored by forming a color coating layer 18 made of a color paint. As shown in Fig. 2(a), the area 16 to be colored of the resin member 10 is subjected to the primer treatment as described above, and a primer treatment layer 23 is formed on the surface of the base material. At this time, since the area 17 of the resin member 10 where the base color is to be retained is provided with the masking 14, the primer can be applied by spraying, for example, and the primer may protrude onto the masking 14 and adhere thereto.

[0028] After forming the primer treatment layer 23, as shown in Fig. 2(b), a colored paint made of a water-based paint as described above is applied onto the primer treatment layer 23 of the portion 16 to be colored to form a colored coating layer 18. For example, the colored paint may be sprayed from a nozzle in a temperature- and humidity-controlled painting booth. At this time, it is acceptable for the colored paint to overflow onto the masking 14.

[0029] After forming the color coating layer 18 on the area 16 to be colored, as shown in Fig. 2(c), a clear paint is applied onto the color coating layer 18 to form a clear coating layer 19. The application of the clear paint may be performed in the same manner as the application of the color paint. Thereafter, the color coating layer 18 and the clear coating layer 19 are heated at a predetermined temperature to dry and harden the area 16 to be colored, thereby forming the colored region 12.

[0030] Next, to form the base color region 11 adjacent to the colored region 12, the colored coating layer 18 and the clear coating layer 19 are cured, and then the masking 14 is peeled off and removed from the resin member 10, as shown in FIG. 2(d). This allows the base color region 11 and the colored region 12 to be formed adjacent to each other with a parting line 13 on the outer surface of the resin member 10, completing the two-tone painting of the resin member 10 as shown in FIG. 2(e).

[0031] According to the method for painting a resin member 10 of this embodiment, a masking 14 is provided on an area 17 of the resin member 10 where the base color is to be retained, an area 16 to be colored is primer-treated, and a coloring paint made of a water-based paint is applied and colored to form a base color area 11 and a colored area 12. In this case, the water-based paint is applied to the area 17 where the base color is to be retained and cured to provide a masking 14 that is releasably adhered to the base.

[0032] Therefore, in order to provide masking 14 for area 17 where the base color is to be retained, the same paint as that applied to area 16 to be colored can be used, and the same painting equipment can be utilized. This eliminates the need to prepare paint and painting equipment used for the actual painting just for masking 14, and masking 14 can be provided easily with simple preparation.

[0033] Moreover, since the masking 14 is provided by applying water-based paint to the area 17 where the base color is to be preserved, it adheres closely to the base material, and no gaps or peeling occurs due to pressure or the like when the colored paint is applied, so that it is possible to reliably prevent the colored paint from adhering to the area 17 where the base color is to be preserved. In addition, there is little risk of the base material of the resin member 10 deteriorating, as occurs with solvent-based paint. Therefore, it is possible to ensure a high level of appearance quality for the base color area 11. Therefore, when providing the base color region 11 and the colored region 12 in the resin member 10, the masking 14 can be easily provided using simple equipment, and the base color region 11 can be formed with excellent appearance quality.

[0034] In the manufacturing method of this embodiment, the area 16 to be colored is covered with the masking jig 21, and the area 17 to be left with the base color is coated with water-based paint to provide the masking 14, so that the area 17 to be left with the base color can be easily coated with the masking 14. Moreover, since water-based paint is applied, even if paint adheres to the masking jig 21, it can be easily cleaned, making it easy to use.

[0035] In the manufacturing method of this embodiment, a clear paint is applied onto a colored coating layer 18 made of a colored paint, and after both are cured, the masking 14 is peeled off. This means that the masking 14 can be used both for applying the water-based paint and the clear paint, making it possible to carry out the painting process efficiently and also allowing the base color region 11 and the colored region 12 to be adjacent to each other with a clear boundary 13.

[0036] The above embodiment can be modified as appropriate within the scope of the present invention. For example, in the above embodiment, when forming the masking 14 with water-based paint, an example was described in which the masking jig 21 was used to cover the area 16 to be colored. However, the masking 14 may also be formed without using the masking jig 21, for example, by applying water-based paint with a brush or the like. [Explanation of symbols]

[0037] 10 Resin parts 11 Base color area 12 Colored area 13. Forget 14 Masking 16 Area to be colored 17 Areas where you want to keep the base color 18 Colored coating layer 19 Clear coating layer 21 Masking jig 22 Masking coating layer 23 Primer treatment layer

Claims

1. A method for coating a resin member, comprising the steps of: providing a masking on a portion of the resin member to be left in its base color; primer-treating the portion of the resin member to be colored; coloring the portion with a coloring paint made of a water-based paint; and removing the masking to form a base color region and a colored region, A method for painting a resin member, comprising applying and curing an aqueous paint that is the same as the colored paint for forming the colored region in an area where the base color is to be retained, thereby providing the masking releasably adhered to the base color region, and then applying the colored paint.

2. 2. The method for coating a resin member according to claim 1, further comprising the steps of: covering the area to be colored with a masking tool; and applying the water-based paint to the area to be left with the base color to provide the masking.

3. 3. The method for coating a resin member according to claim 1, further comprising the steps of: applying a clear coating onto the layer of colored coating material; curing the clear coating; and removing the masking.

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