Resin molded article and method for producing resin molded article

Abstract

A resin molded article is provided with: a base material containing a resin; a first coating film layer formed on the surface of the base material and having a thickness of 100 [mu] m or more and 1000 [mu] m or less; and a second coating film layer formed on the surface of the first coating film layer and having a thickness of 100 [mu] m or more and 1000 [mu] m or less.

Description

Technical Field

[0001] The present disclosure relates to a resin molded body and a method for producing the resin molded body. Background Art

[0002] Conventionally, a coating method for forming a coating layer of a resin molded body in a mold for molding the resin molded body is known (for example, see Patent Document 1). Such a coating method is called an in-mold coating method, which can reduce the use of volatile organic compounds and is a known environmentally friendly coating method.

[0003] In addition, there is also known a resin molding method in which two resin materials are integrated using a core-pulling injection molding device (for example, refer to Patent Document 2).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2006-76174

[0007] Patent Document 2: Japanese Patent Application Publication No. 2005-88527 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] The coating method using the in-mold coating method of Patent Document 1 does not disclose the formation of two coating film layers. In addition, Patent Document 2 discloses a method for integrating two resin layers, but does not disclose a method for forming a coating film layer.

[0010] The present invention aims to provide a resin molded body having a plurality of coating film layers formed thereon by an in-mold coating method and a method for producing the resin molded body.

[0011] Technical solutions for solving technical problems

[0012] The resin molded body involved in the present disclosure comprises: a substrate containing a resin; a first coating layer with a thickness of 100 microns to 1000 microns formed on the surface of the substrate; and a second coating layer with a thickness of 100 microns to 1000 microns formed on the surface of the first coating layer.

[0013] In addition, the method for manufacturing a resin molded body involved in the present disclosure includes: a process of injecting a resin material into a mold cavity formed by a first mold and a second mold to form a substrate; a first coating process of opening the first mold and the second mold, injecting a first coating film forming material between the substrate and the first mold, and forming a first coating film layer on the surface of the substrate; and a second coating process of opening the first mold and the second mold again, injecting a second coating film forming material between the first coating film layer and the first mold, and forming a second coating film layer on the surface of the first coating film layer.

[0014] Effects of the Invention

[0015] In the resin molded body, the first coating layer has a thickness of a coating layer formed by an in-mold coating method, and the second coating layer also has a thickness of a coating layer formed by an in-mold coating method.

[0016] Furthermore, according to such a method for producing a resin molded body, the first coating layer and the second coating layer can be formed by an in-mold coating method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a side view of a resin molded body.

[0018] Figure 2 yes Figure 1 AA section view.

[0019] Figure 3 This is a schematic diagram of a mold device used in the in-mold coating method.

[0020] Figure 4 FIG. 1 is a diagram showing a method for producing a resin molded body.

[0021] Figure 5 FIG. 2 is a diagram showing a method for producing a resin molded body. DETAILED DESCRIPTION

[0022] Hereinafter, with reference to the attached drawings, the embodiments of the present disclosure will be described. Figure 1 While explaining.

[0023] like Figure 1 as well as Figure 2 As shown, the resin molded body 1 includes a substrate 2, a first coating layer 4, and a second coating layer 6. In the present embodiment, the resin molded body 1 is a resin component used as a decorative panel, a bumper, etc. used in the interior of an automobile. The resin molded body 1 has a surface 1a and a back surface 1b. When the resin molded body 1 is an interior component of an automobile, the surface 1a of the resin molded body 1 is assembled toward the user of the automobile. In addition, when the resin molded body 1 is an exterior component of an automobile, the surface 1a of the resin molded body 1 is configured to face the outside of the automobile.

[0024] The substrate 2 is a resin member that becomes a base for forming the first coating layer 4. The substrate 2 is formed of a thermoplastic resin material. Examples of the resin material include polypropylene, polyethylene, ABS resin (acrylonitrile-butadiene-styrene copolymer), PC resin (polycarbonate resin), and the like.

[0025] The first coating layer 4 is a coating layer formed on one side of the surface 1a of the substrate 2. More specifically, the first coating layer 4 is formed by a first coating forming material attached to the surface of the substrate 2 by an in-mold coating method. The first coating forming material, for example, may contain a coating suitable for the in-mold coating method described in Japanese Patent Publication No. 6-107750 and Japanese Patent Publication No. 8-113761. In addition, in the present embodiment, the first coating layer 4 is a colored layer formed by a coating containing a colorant. It should be noted that the first coating layer 4 may also contain a so-called bright material composed of a metal sheet, a mica sheet, and a glass bead. The thickness of the first coating layer 4 formed by the in-mold coating method is more than 100 microns and less than 1000 microns.

[0026] In addition, the first coating layer 4 is a coating layer containing a release agent and / or having a release agent attached to the surface. That is, the coating material for the first coating layer 4 sometimes contains a release agent. In addition, the coating material for the first coating layer 4 may not contain a release agent component, and the release agent sprayed onto the mold may be stacked on the coating surface. The release agent is used to inhibit the first coating layer 4 from adhering to the first mold 22 described later (see Figure 3 ) agent. The mold release agent makes it easy to separate the molded product from the mold. In the present embodiment, the mold release agent is, for example, an agent containing light naphtha and wax. Wax is, for example, paraffin wax and microcrystalline wax. In addition, the mold release agent may also contain polydimethylsiloxane. In a state where the mold release agent is attached to the surface of the first coating layer 4 formed by the in-mold coating method, the second coating layer 6 described later is formed.

[0027] The second coating layer 6 is a coating layer formed on the surface of the first coating layer 4. The second coating layer 6 contains a coating formed by mixing and curing two different second coating forming materials. In the present embodiment, the coating forming the second coating layer 6 is a urethane coating formed by mixing and curing a polyol (an example of the first material) and an isocyanate (an example of the second material). However, as long as the second coating layer 6 contains a coating obtained by mixing and curing two or more different materials, it may also be a coating other than a urethane coating. Curing includes curing caused by a reaction of mixing different materials and curing caused by a temperature drop after mixing two different materials.

[0028] In the present embodiment, the second coating layer 6 is a transparent layer that is a transparent coating and covers the first coating layer 4. The transparent layer has the function of adding gloss to the color of the first coating layer 4. In addition, the transparent layer has the function of protecting the first coating layer 4. Therefore, in the present embodiment, the second coating layer 6 is formed by a coating that does not contain a colorant or a translucent coating that contains a colorant. However, the second coating layer 6 can be any coating as long as it is a coating in which two different materials are mixed and cured.

[0029] The thickness of the second coating layer 6 is 100 μm to 1000 μm. In this embodiment, the thickness of the transparent layer as the second coating layer 6 is set equal to or thinner than the thickness of the color layer as the first coating layer 4 .

[0030] Next, use Figure 3 , Figure 4 as well as Figure 5 The method for producing the resin molded body 1 is described below. Figure 3 As shown, in this embodiment, the mold device 20 used in the in-mold coating method is a resin injection molding device including a first mold (an example of the first mold) 22, a second mold (an example of the second mold) 24, a resin injector 26, and a paint injector 28. The first mold 22 and the second mold 24 are closed to form a cavity 30. However, the mold device 20 may be any mold as long as the in-mold coating method can be performed.

[0031] The resin injector 26 is used to inject the resin into the substrate 2 (see Figure 2 ) is a nozzle for injecting a resin material. In the present embodiment, the resin injector 26 is arranged on the side of the second mold 24 of the mold cavity 30. The resin injector 26 can also be arranged toward the supply passage 30a. The supply passage 30a is connected to the mold cavity 30. The paint injector 28 is a nozzle for injecting a first coating film forming material and a second coating film forming material. In the present embodiment, the paint injector 28 is arranged on the side of the first mold 22 of the mold cavity 30.

[0032] First, if Figure 4 As shown in (a), a resin material is injected from a resin injector 26 into the cavity 30 to form a substrate 2. Then, the mold device 20 is opened, and the second mold 24 is pulled away from the first mold 22, thereby separating the first mold 22 from the substrate 2. In addition, a release agent is applied to the surface of the first mold 22 facing the cavity 30 to form a layer of the release agent. It should be noted that in the case where the first coating film forming material contains a release agent, the release agent coating step can also be omitted. In addition, in the case where the first coating film forming material does not contain a release agent, the release agent can also be applied to the surface of the first mold 22 and / or the second mold 24 facing the cavity 30 before forming the substrate 2.

[0033] like Figure 4 As shown in (b), when forming the first coating layer 4, the second mold 24 is pulled away from the first mold 22 so that the distance between the first mold 22 and the substrate 2 is 100 micrometers or more and 1000 micrometers or less. The first coating film forming material is injected into the gap formed between the first mold 22 and the substrate 2 via the paint injector 28 (first coating film step). At this time, in order to facilitate the flow of the first coating film forming material, the first mold 22 and / or the second mold 24 may be heated.

[0034] like Figure 4 As shown in (c), when the first coating layer 4 is formed, the first mold 22 moves toward the second mold 24, and the first coating layer 4 is compressed (refer to Figure 4 (white arrow in (c)) (first compression step). As a result, the first coating layer 4 can be made to fit tightly to the substrate 2. In addition, the surface transfer of the first mold 22 can be performed on the first coating layer 4. In addition, by compressing the first coating layer 4, it is possible to prevent depressions from being generated on the surface of the first coating layer 4 due to shrinkage during the curing of the first coating layer 4. At this time, the first distance for moving the first mold 22 toward the second mold 24 preferably changes with the thickness of the first coating layer 4. Preferably, the thicker the thickness of the first coating layer 4, the larger the first distance. As a result, even when the thickness of the first coating layer 4 is thick, the first coating layer 4 can be easily bonded to the substrate 2. The same is true for the second coating layer 6 described later.

[0035] Then, if Figure 5 As shown in (a), the mold opening device 20 (refer to Figure 5 (a) white arrow) so that the first mold 22 is in a state of being separated from the surface of the first coating layer 4 by a distance of 100 μm or more and 1000 μm or less. Then, as Figure 5 As shown in (b), a second coating film forming material containing two different materials for forming the second coating film layer 6 is injected into the mold cavity 30 (second coating film step). At this time, the two different materials are mixed and injected at the front end of the coating material injector 28. The two injected materials react and solidify while flowing on the surface of the first coating film layer 4 as coating materials.

[0036] like Figure 5 As shown in (c), after the coating is cured, the first mold 22 moves toward the second mold 24, and the second coating layer 6 is compressed (refer to Figure 5(white arrow in (c)) (second compression step). It should be noted that, in the present embodiment, the thickness of the second coating layer 6 is set to be equal to or thicker than the thickness of the first coating layer 4. Therefore, when the second coating layer 6 is compressed, the second distance to move the first mold 22 is equal to or longer than the first distance to move the first mold 22 when the first coating layer 4 is compressed.

[0037] Finally, the mold opening device 20 pulls the first mold 22 away from the second mold 24 to take out the resin molded body 1.

[0038] As described above, with such a resin molded body 1, the first coating layer 4 and the second coating layer 6 can be formed by an in-mold coating method. As a result, the use of volatile organic compounds can be reduced compared to the case where the coating layer is formed by coating. In addition, the second coating layer 6 is formed on the first coating layer 4 by an in-mold coating method. As a result, a thick coating layer (for example, a coating layer with a thickness of 100 microns or more) that cannot be formed due to sagging during coating can be formed. As a result, the durability of the resin molded body 1 is improved.

[0039] In addition, in the manufacturing method of the resin molded body 1 of the present embodiment, the first coating layer 4 and the second coating layer 6 are compressed. Thus, the coating layers can be more firmly bonded and difficult to peel off. In addition, the first coating layer 4 and the second coating layer 6 are manufactured using the same first mold 22 and the second mold 24. Thus, compared with the case of using different molds, the manufacturing cost can be suppressed.

[0040] In addition, in the manufacturing method of the resin molded body 1 of the present embodiment, the first mold 22 and the second mold 24 are not released (that is, the cavity 30 is released) before the step of taking out the resin molded body 1. As a result, dust and the like are not attached to each coating layer. As a result, the resin molded body 1 manufactured by such a manufacturing method does not peel off the coating film and is easy to maintain a good appearance.

[0041] <Other embodiments>

[0042] As mentioned above, although embodiment of this disclosure was described, this disclosure is not limited to the said embodiment, Various changes are possible within the range which does not deviate from the summary of invention.

[0043] For example, in the above-mentioned embodiment, the resin molded body 1 is described as a part for automobiles, but the present disclosure is not limited thereto. The resin molded body 1 may be a resin part for other than automobiles.

[0044] In addition, as the resin material forming the substrate 2, thermoplastic resins such as polypropylene, polyethylene, ABS resin, and PC resin are exemplified, but the present disclosure is not limited thereto. The substrate 2 may be, for example, a thermoplastic resin such as polyamide, polyethylene terephthalate, and modified polyphenylene ether, or an alloy material of these thermoplastic resins, or may be a resin material in which a fibrous or flaky filler is blended in these thermoplastic resins. In short, the substrate 2 may be any resin as long as it is formed of a thermoplastic resin.

[0045] In the above embodiment, the first coating layer 4 and the second coating layer 6 are formed between the substrate 2 and the first mold 22, but the present disclosure is not limited thereto. For example, the substrate 2 may be attached to the first mold 22 side, and a coating forming material may be injected after a gap is left between the second mold 24 and the substrate 2, so that the first coating layer 4 and the second coating layer 6 are formed between the substrate 2 and the second mold 24.

[0046] Description of Reference Numerals

[0047] 1: resin molded body; 1a: surface; 1b: back side; 2: substrate; 4: first coating layer; 6: second coating layer; 20: mold device; 22: first mold; 24: second mold; 26: resin injector; 28: paint injector; 30: mold cavity.

Claims

1. A resin molded body comprising: A substrate containing a resin; a first coating layer having a thickness of not less than 100 micrometers and not more than 1000 micrometers formed on the surface of the substrate; and A second coating layer having a thickness of 100 μm to 1000 μm is formed on the surface of the first coating layer.

2. The resin molded article according to claim 1, wherein At least one of the first coating film layer and the second coating film layer contains a coating material obtained by mixing and curing a first material and a second material different from the first material.

3. The resin molded article according to claim 2, wherein The first material is a polyol, and the second material is an isocyanate.

4. A method for producing a resin molded body, comprising: A step of injecting a resin material into a cavity formed by the first mold and the second mold to form a substrate; A first coating step of opening the first mold and the second mold, injecting a first coating film forming material between the substrate and the first mold, and forming a first coating film layer on the surface of the substrate; as well as A second coating step of opening the first and second molds again, injecting a second coating film forming material between the first coating film layer and the first mold, and forming a second coating film layer on the surface of the first coating film layer.

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