WO2024070325A1

WO2024070325A1 - Method for manufacturing in-mold-coated molded article, and mold for in-mold-coated molded article for use therewith

Info

Publication number: WO2024070325A1
Application number: PCT/JP2023/029950
Authority: WO
Inventors: 建登清水; 寛斗安藤; 幹夫田多井; 広男近藤; 正己鈴木; 憲宏柿沼; 有人飯田
Original assignee: 株式会社東海理化電機製作所; 株式会社精工技研
Priority date: 2022-09-26
Filing date: 2023-08-21
Publication date: 2024-04-04
Also published as: JP2024047249A

Abstract

[Problem] To provide a method for manufacturing an in-mold-coated molded article in which a step for coating an outer surface of a molding base material with a liquid coating agent and a step for forming a desired pattern are performed simultaneously. [Solution] Provided is a method for manufacturing an in-mold-coated molded article 28 in which a molding base material 2 is attached to a first mold 1, the first mold 1 is abutted on a second mold 3 so as to cover the molding base material 2, a coating gap is formed between an inner surface of the second mold 3 and an outer surface of the molding base material 2, and a liquid coating agent (paint 5) is injected into the coating gap 4 and attached to the outer surface of the molding base material 2, wherein a convex part 30 corresponding to a pattern desired to be added to the outer surface of the molding base material 2 is formed on the inner surface of the second mold 3 to a height H corresponding to the coating gap 4, and the liquid coating agent 5 is injected into the coating gap 4 with the first mold 1 abutted on the second mold 3 and with the convex part 30 pressed onto the outer surface of the molding base material 2.

Description

Manufacturing method of in-mold coated molded product and mold for in-mold coated molded product used therein

The present invention relates to a method for manufacturing an in-mold coated molded product in which a coating gap is formed between the outer surface of a substrate sandwiched between a pair of molds and the inner surface of the molds, and a liquid coating agent is injected into the coating gap to adhere to the outer surface of the substrate, and a mold for an in-mold coated molded product used in the method. In particular, the present invention relates to a method for manufacturing an in-mold coated molded product in which a desired pattern is formed by preventing the liquid coating agent from adhering to desired locations on the outer surface of the substrate, and a mold for an in-mold coated molded product used in the method.

Amid growing interest in environmental issues in recent years, in-mold coating (IMC) has been attracting attention as an alternative painting technique that does not use organic solvents and is highly effective in reducing CO2 emissions. IMC is a technique that utilizes the mold used for molding to inject a functional liquid coating agent (e.g. paint) into the gap between the outer surface of the molded substrate and the inner surface of the mold, and then forms a film (e.g. paint film) on the outer surface of the molded substrate by heating (see Patent Document 1).

　IMC's features include: (1) it is environmentally and human-friendly because it does not use the organic solvents used in general spray painting; (2) it does not require equipment for the painting process (spraying, oven heat treatment); and (3) because the paint is not diluted with organic solvents, the rate at which the material (paint) before application is formed as a coating on the outer surface of the molded substrate (coating efficiency) is very high, resulting in very little waste.

The purpose of painting resin molded products is to give the original outer surface of the material a vivid color, gloss, or metallic look that cannot be obtained by kneading, or to hide defects in appearance that occur during molding, thereby enhancing the design and giving the product a luxurious feel. Furthermore, there are many products in our daily lives that have functions that improve visibility and take operability into consideration. An example of this type of product is a computer keyboard with letters and symbols printed on the surface of the keys.

When printing or painting symbols or letters on the surface of computer keyboard keys, screen printing using silk mesh is usually used if the surface to be printed or painted is flat, and pad printing using elastic silicone rubber is used if the surface is curved. However, both of these conventional methods use paint diluted with organic solvents and require oven treatment, which has a large impact on the environment.

On the other hand, a highly functional switch part for use in environments with little lighting, such as indoors, in a car, or at night, is known, for example as shown in Figure 12. Figure 12(a) is a perspective view of the switch part, and Figure 12(b) is a cross-sectional view taken along line b-b in Figure 12(a). This switch part has a generally black surface with a white pattern (star-shaped pattern) partially displayed, with a light-transmitting material used for the white pattern (star-shaped pattern) part. In devices used in dark rooms, cars, or at night with little lighting, when the main power is turned on, a light (not shown) on the back of the switch part turns on and the white area (the white pattern (star-shaped pattern) part) lights up and can be recognized, allowing it to be used in dark environments.

This type of switch part is usually manufactured by forming a cylindrical molding substrate 2 whose top surface is covered with a transparent or translucent resin, first coating the entire outer surface of the molding substrate 2 with an opaque paint such as black to form a coating film 27, and then removing the coating film 27 only from the design area in the center of the top surface, which is a star-shaped pattern 31. A known method for partially removing this coating film 27 is the laser irradiation method, in which a laser beam is used to vaporize and remove the black coating film 27 only from the design area (star-shaped pattern 31) (see Patent Documents 2 and 3).

Patent No. 3617807 JP 2002-146558 A JP 2005-7403 A

However, because the laser irradiation method is a high-heat treatment, in order to ensure the clearness of the boundary between the design area (star-shaped pattern part 31: white) of the substrate 2 exposed by removing the coating film 27 by irradiation with a laser beam and the painted coating film 27 part (black) in FIG. 12(a) while minimizing the thermal impact on the substrate 2 itself, the spot diameter of the laser beam must be small, and there is a restriction that the irradiation energy cannot be large. Due to this restriction, in order to increase productivity, the coating film 27 formed on the outer surface of the substrate 2 must be as thin as possible (for example, 50 μm or less), and detailed control of the coating film thickness is necessary, which leads to increased costs.

In addition, the initial cost of installing laser processing equipment is high, and since processing is done by drawing a small spot in one stroke, processing a large area requires an extremely long processing time, which is a factor that significantly increases manufacturing costs.

In addition, the laser irradiation method requires two steps: a step of painting the outer surface of the molding substrate 2 and a step of removing part of the painted coating film 27 with a laser beam, which increases the number of steps and the manufacturing time, resulting in an unavoidable increase in costs.

The object of the present invention, which was devised in consideration of the above circumstances, is to provide a method for manufacturing an in-mold coated molded product in which a coating gap is formed between the outer surface of a substrate sandwiched between a pair of molds and the inner surface of the molds, and a liquid coating agent is injected into the coating gap to adhere to the outer surface of the substrate, and a mold for an in-mold coated molded product used therein, in which when providing an area free of liquid coating agent at desired locations on the outer surface of the substrate to form a desired pattern, irradiation with a laser beam is not required, shortening manufacturing time and reducing costs.

　Invented to achieve the above object, the present invention provides a method for manufacturing an in-mold coated molded product by mounting a molding substrate on a first mold, abutting the first mold with the mounting substrate against a second mold so as to cover the molding substrate, forming a coating gap between the inner surface of the second mold and the outer surface of the molding substrate, and injecting a liquid coating agent into the coating gap to adhere to the outer surface of the molding substrate, in which a convex portion corresponding to a desired pattern to be applied to the outer surface of the molding substrate is formed on the inner surface of the second mold at a height corresponding to the coating gap, and when the first mold with the mounting substrate is abutted against the second mold so as to cover the molding substrate, the convex portion formed on the inner surface of the second mold comes into contact with the outer surface of the molding substrate, and in this state, liquid coating agent is injected into the coating gap to adhere the liquid coating agent to the outer surface of the molding substrate except for the portion with the convex portion, thereby coating the outer surface of the molding substrate with the liquid coating agent except for the portion with the desired pattern (Claim 1).

In this manufacturing method for in-mold coated molded products, the convex portion formed on the inner surface of the second mold is formed to a height slightly higher than the coating gap, and when the first mold with the molding substrate attached is butted against the second mold so as to cover the molding substrate, the convex portion formed on the inner surface of the second mold is pressed against the outer surface of the molding substrate, thereby preventing the liquid coating agent from penetrating between the convex portion and the outer surface of the molding substrate when the liquid coating agent is injected into the coating gap (Claim 2).

The present invention also provides a method for manufacturing an in-mold coated molded product, which comprises mounting a molding substrate on a first mold, abutting the first mold with the mounting substrate against a second mold so as to cover the molding substrate, forming a coating gap between the inner surface of the second mold and the outer surface of the molding substrate, and injecting a liquid coating agent into the coating gap to adhere to the outer surface of the molding substrate, in which convex portions corresponding to a desired pattern to be applied to the outer surface of the molding substrate are formed on the outer surface of the molding substrate at a height corresponding to the coating gap, and when the first mold with the mounting substrate is abutted against the second mold so as to cover the molding substrate, the convex portions formed on the outer surface of the molding substrate come into contact with the inner surface of the second mold, and in this state, liquid coating agent is injected into the coating gap to adhere the liquid coating agent to the outer surface of the molding substrate except for the portion with the convex portion, thereby coating the outer surface of the molding substrate with the liquid coating agent except for the portion with the desired pattern (Claim 3).

In this manufacturing method for in-mold coated molded products, the convex portion formed on the outer surface of the molding substrate is formed to a height slightly higher than the coating gap, and when the first mold with the molding substrate attached is butted against the second mold so as to cover the molding substrate, the convex portion formed on the outer surface of the molding substrate is pressed against the inner surface of the second mold, thereby preventing the liquid coating agent from penetrating between the convex portion and the outer surface of the molding substrate when the liquid coating agent is injected into the coating gap (Claim 4).

In the manufacturing method of the in-mold coated molded product described in any one of claims 1 to 4 above, a thermosetting paint may be used as the liquid coating agent, and the thermosetting paint may be injected into the coating gap formed between the inner surface of the second mold and the outer surface of the molded substrate, after which the thermosetting paint may be hardened by a thermal reaction using the second mold as a heat source and adhere to the outer surface of the molded substrate (claim 5).

Furthermore, according to the present invention, there is provided a mold for an in-mold coated molded product used in the manufacturing method for an in-mold coated molded product described in claim 1, characterized in that a convex portion corresponding to a desired pattern to be applied to the outer surface of the molded substrate is formed on the inner surface of the second mold at a height corresponding to the coating gap, and when the first mold with the molded substrate attached is abutted against the second mold so as to cover the molded substrate, the convex portion formed on the inner surface of the second mold comes into contact with the outer surface of the molded substrate (claim 6).

Furthermore, according to the present invention, there is provided a mold for an in-mold coated molded product used in the manufacturing method for an in-mold coated molded product described in claim 2, characterized in that a convex portion corresponding to a desired pattern to be applied to the outer surface of the molded substrate is formed on the inner surface of the second mold at a height slightly higher than the coating gap, and when the first mold with the molded substrate attached is abutted against the second mold so as to cover the molded substrate, the convex portion formed on the inner surface of the second mold is pressed against the outer surface of the molded substrate (claim 7).

The method for producing an in-mold coated molded product and the mold for an in-mold coated molded product used therein according to the present invention can achieve the following effects.
(1) According to the invention of claim 1, in a manufacturing method of an in-mold coated molded product, a molding substrate is attached to a first mold, the first mold is butted against a second mold so as to cover the molding substrate, a coating gap is formed between the inner surface of the second mold and the outer surface of the molding substrate, and a liquid coating agent is injected into the coating gap to adhere to the outer surface of the molding substrate. On the inner surface of the second mold, a convex portion corresponding to a desired pattern to be applied to the outer surface of the molding substrate is formed at a height corresponding to the coating gap. When the first mold with the molding substrate attached is butted against the second mold so as to cover the molding substrate, the convex portion formed on the inner surface of the second mold comes into contact with the outer surface of the molding substrate. In this state, liquid coating agent is injected into the coating gap to adhere the liquid coating agent to the outer surface of the molding substrate other than the portion where the convex portion comes into contact, and the outer surface of the molding substrate is coated with the liquid coating agent except for the portion with the desired pattern. Therefore, the process of painting the outer surface of the molding substrate and the process of forming the desired pattern on the outer surface of the molding substrate can be performed simultaneously, shortening the manufacturing time and promoting cost reduction.
(2) According to the invention of claim 3, in a manufacturing method of an in-mold coated molded product, a molding substrate is attached to a first mold, the first mold is butted against a second mold so as to cover the molding substrate, a coating gap is formed between the inner surface of the second mold and the outer surface of the molding substrate, and a liquid coating agent is injected into the coating gap to adhere to the outer surface of the molding substrate. On the outer surface of the molding substrate, convex portions corresponding to a desired pattern to be applied to the outer surface of the molding substrate are formed at a height corresponding to the coating gap. When the first mold with the molding substrate attached is butted against the second mold so as to cover the molding substrate, the convex portions formed on the outer surface of the molding substrate come into contact with the inner surface of the second mold. In this state, liquid coating agent is injected into the coating gap to adhere the liquid coating agent to the outer surface of the molding substrate other than the portion where the convex portions come into contact. Thus, the outer surface of the molding substrate is coated with the liquid coating agent except for the portion with the desired pattern. Therefore, the process of painting the outer surface of the molding substrate and the process of forming the desired pattern on the outer surface of the molding substrate can be performed simultaneously, shortening the manufacturing time and promoting cost reduction.
(3) Unlike the conventional method, there is no need to remove the desired pattern of the coating applied to the entire outer surface of the molding substrate with a laser beam, so there is no initial cost for introducing laser processing equipment. In addition, when removing the coating film of the desired pattern with a laser beam, it is necessary to make the coating film as thin as possible (for example, 50 μm or less) to increase productivity, but in the present invention, since the coating film is not removed with a laser beam, there is no need to make the coating film thin, and there is no cost for managing the coating film thin. In addition, since the present invention can be realized even if the coating film is made to be somewhat thick, the durability of the coating film during aging is improved by making the coating film thicker.

FIG. 1 is an explanatory diagram of a first mold and a second mold constituting a mold for an in-mold coated molded product used in a manufacturing method of an in-mold coated molded product according to a first embodiment of the present invention, where (a) is a plan view and (b) is a cross-sectional view along line b-b in (a). 1B is separated from the second mold, and the molding substrate, the sprue, and the runner are removed. FIG. FIG. 1 is an explanatory diagram of a molding substrate used in a first embodiment, where (a) is a perspective view and (b) is a cross-sectional view taken along line bb in (a). 4 is a view taken along line IV-IV in FIG. 2, and is a perspective view showing a cavity formed in a second mold and a protrusion formed on the inner surface of the cavity. FIG. 3 is a perspective view showing a step following FIG. 2 . FIG. 6 is a perspective view showing a step following FIG. 5 . FIG. 7 is a perspective view showing a step following FIG. 6 . FIG. 8 is a perspective view showing a step following FIG. 7 . 5A is a cross-sectional view taken along line IXa-IXa in FIG. 5, and FIG. 6B is a cross-sectional view taken along line IXb-IXb in FIG. 7, (c) is a cross-sectional view taken along the line Xc-Xc in FIG. 7, and (d) is a cross-sectional view showing the state in which the liquid coating agent has been injected into the coating gap. 10(e) is a cross-sectional view showing a step following FIG. 10(d), and FIG. 11(f) is a cross-sectional view showing a step following FIG. 11(e) and corresponds to the cross-sectional view taken along line XIf-XIf in FIG. FIG. 1 is an explanatory diagram of an in-mold coated molded product in which a coating is applied to a molding substrate except for the area with a desired pattern in the first embodiment; (a) is a perspective view, and (b) is a cross-sectional view along line bb in (a). FIG. 11 is an explanatory diagram of a first mold and a second mold that constitute a mold for an in-mold coated molded product used in a manufacturing method for an in-mold coated molded product according to a second embodiment of the present invention, in which (a) is a cross-sectional view showing how the first mold is butted against the second mold to injection mold the molded substrate, and (b) is a cross-sectional view showing how the first mold is separated from the second mold to remove the molded substrate. 13(c) is a cross-sectional view showing the process following FIG. 13(b) in which the molding substrate has been replaced with the painting core of the painting mold section, and FIG. 13(d) is a cross-sectional view showing the process following FIG. 13(c) in which the first mold has been abutted against the second mold to form a coating gap. 14(e) is a cross-sectional view showing the step following FIG. 14(d) injecting a liquid coating agent into the coating gap, and FIG. 14(f) is a cross-sectional view showing the step following FIG. 14(e) in which the first mold is separated from the second mold to remove the coated in-mold coated molded product. FIG. 11 is an explanatory diagram of an in-mold coated molded product in a second embodiment, in which a coating is applied to a molding substrate except for the area with a desired pattern; (a) is a perspective view, and (b) is a cross-sectional view along line bb in (a).

Below, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings. The dimensions, materials, and other specific values shown in the embodiment are merely examples to facilitate understanding of the invention, and do not limit the present invention unless otherwise specified. In this specification and drawings, elements that have substantially the same function and configuration are given the same reference numerals to avoid duplicated explanations, and elements that are not directly related to the present invention are not illustrated.

(Outline of manufacturing method for in-mold coated molded products)
The manufacturing method of the in-mold coated molded product according to the present invention is based on the following manufacturing method: a molding substrate 2 is attached to a first mold 1 as shown in Figures 9(a) and 9(b), the first mold 1 with the molding substrate 2 attached is abutted against a second mold 3 as shown in Figure 10(c) so as to cover the molding substrate 2, a coating gap 4 is formed between the inner surface of the second mold 3 and the outer surface of the molding substrate 2, and a liquid coating agent 5 (paint, etc.) is injected into the coating gap 4 as shown in Figure 10(d) to adhere to the outer surface of the molding substrate 2.

First Embodiment
The manufacturing method of the in-mold coated molded product according to the first embodiment of the present invention is characterized in that, as shown in FIG. 4 and FIG. 9(a), a convex portion 30 corresponding to a desired pattern to be applied to the outer surface of the molding substrate 2 is formed on the inner surface of the second mold 3 at a height H corresponding to the coating gap 4 shown in FIG. 10(c). As shown in FIG. 10(c), when the first mold 1 with the molding substrate 2 attached is butted against the second mold 3 so as to cover the molding substrate 2, the convex portion 30 comes into contact with the outer surface of the molding substrate 2. As shown in FIG. 10(d), by injecting a liquid coating agent 5 (paint, etc.) into the coating gap 4 in this state, as shown in FIG. 11(e), the liquid coating agent 5 (paint, etc.) is attached to the outer surface of the molding substrate 2 other than the portion contacted by the convex portion 30. As shown in FIG. 11(f) and FIG. 12, the outer surface of the molding substrate 2 is coated (painted) with the liquid coating agent 5 (paint, etc.) except for the portion 31 of the desired pattern to form a coating film 27.

The following provides a detailed description of the method for manufacturing an in-mold coated molded product according to the first embodiment and the mold for the in-mold coated molded product used therein.

(Molds for in-mold coated products)
1(a), 1(b), and 2 show an example of a mold for an in-mold coated molded product used in the manufacturing method of an in-mold coated molded product according to the first embodiment of the present invention. This mold is composed of a lower first mold 1 in which a convex molding core 9 and a coating core 10 are formed, and an upper second mold 3 in which a concave molding cavity 11 and a coating cavity 12 are formed, and is equipped with a molding mold part 13 consisting of the molding core 9 and the molding cavity 11, and a coating mold part 14 consisting of the coating core 10 and the coating cavity 12. Note that the first mold 1 and the second mold 3 are not limited to being arranged vertically (vertical type), but may be arranged left and right (horizontal type). Various mechanisms such as hydraulic or electric mechanisms are used for the actuator that abuts the first mold 1 against the second mold 3 to clamp the mold and separates them to take out the molded product.

When the first mold 1 is brought closer to the second mold 3 from the state shown in FIG. 2, and the butting surface 6 of the first mold 1 butts against the butting surface 7 of the second mold 3 as shown in FIG. 1(b), the molding core 9 is inserted into the molding cavity 11, forming a molding gap 15 between them for molding the molding substrate 2, and at the same time, the paint core 10 is inserted into the paint cavity 12, forming a coating gap 4 (see FIG. 10(c)) between the molding substrate 2 attached to the paint core 10 and the paint cavity 12 as described below. Here, the molding core 9 and the molding cavity 11 constitute the molding mold section 13, and the paint core 10 and the paint cavity 12 constitute the paint mold section 14.

As shown in FIG. 2, inside the second mold 3, a sprue passage 16 is formed in the vertical direction, located between the molding cavity 11 and the coating cavity 12, and a resin injection port 17 is formed on the top surface of the second mold 3 to inject resin for molding the molding substrate into the sprue passage 16. A runner groove portion 19 is formed on the butting surface 7 of the second mold 3, one end of which is connected to the sprue passage 16 and the other end of which is connected to the molding cavity 11 via a gate 18. As shown in FIG. 1(b), when the butting surface 6 of the first mold 1 is butted against the butting surface 7 of the second mold 3, the runner groove portion 19 is covered by the butting surface 6 of the first mold 1 to become a runner passage 20. In addition, inside the second mold 3, a paint passage 22 is formed, one end of which is connected to the coating cavity 12 via a gate 21, and a paint injection port 23 is formed on the side of the second mold 3 to inject paint 5 (liquid coating agent) into the other end of the paint passage 22.

(Resin for forming the molding substrate 2)
As shown in FIG. 1(b), the resin injected into a resin injection port 17 in order to mold the substrate 2 in the molding die section 13 may be either a thermoplastic resin or a thermosetting resin.

Thermoplastic resins to be injected into the resin injection port 17 include, for example, polyolefin resins such as polyethylene, polypropylene, and ethylene-vinyl acetate polymer; crystalline general-purpose resins such as polyvinyl alcohol; crystalline engineering plastics such as polyamide, polyethylene terephthalate, and polyacetal; amorphous general-purpose resins such as polyvinyl chloride, polyvinylidene chloride, ABS resin, AES resin, ASA resin, and PMMA resin; amorphous engineering plastics such as polycarbonate, modified PPO, polyimide, polyarylate, and polyetherimide; and polystyrene resin and thermoplastic elastomers, which can be mixed and used. In addition, it is also possible to use a mixture of the above-mentioned various thermoplastic resins with other components, such as thermosetting resins such as polyurethane resin, phenolic resin, melamine resin, and epoxy resin, within the range that maintains the thermoplasticity. Furthermore, it is also possible to use composite materials in which various fibers such as carbon fiber and glass fiber are added to these various materials.

Thermosetting resins injected into the resin injection port 17 include molding compounds called bulk molding compounds (BMC) and tough molding compounds (TMC), which have a matrix of unsaturated polyester resin, phenolic resin, etc.

(Paint as liquid coating agent 5)
As shown in FIG. 10(d), in the coating mold part 14, the liquid coating agent 5 injected into the paint inlet 23 to coat the outer surface of the molding substrate 2 is, for example, a paint 5, and as an example of the paint 5, a thermosetting paint is used. Hereinafter, the concept of the liquid coating agent 5 includes paint 5 and thermosetting paint 5. The thermosetting paint 5 is injected from the paint inlet 23 into the coating gap 4 formed between the inner surface of the coating cavity 12 of the second mold 3 and the outer surface of the molding substrate 2, and then hardens by a thermal reaction using the second mold 3 as a heat source, and is attached to the outer surface of the molding substrate 2. In order to heat and harden the thermosetting paint 5 in the coating gap 4, a heater is built into the second mold 3. As the heater, for example, an electric resistance wire such as a nichrome wire arranged near the coating cavity 12 of the second mold 3 is considered. In addition, as a heating method, temperature controllability is required, and when the set temperature is 120° C. or less, water temperature control is used, and when it exceeds 120° C., oil temperature control is used.

The paint 5 injected into the paint inlet 23 may be a thermosetting paint such as an alkyd resin-based, epoxy resin-based, polyurethane-based, or vinyl resin-based paint, or a radical polymerization type paint made of an epoxy acrylate oligomer, a urethane acrylate oligomer, a polyester acrylate oligomer, or these various oligomers and an ethylenically unsaturated monomer, or an oxidative polymerization type paint such as an alkyd resin-based, epoxy resin ester-based, or fatty acid-modified urethane resin-based paint, or a multi-liquid reaction type paint such as an epoxy resin-based, polyurethane-based, or unsaturated polyester-based paint, or a functional paint in which metal powder, pigment, ultraviolet absorber, etc. are added to these paints, a fluororesin-based lacquer, a silicone resin-based lacquer, or a silane-based hard coat agent, etc. can be used.

(Protrusion 30)
As shown in FIG. 4, which is a view taken along the arrow IV-IV in FIG. 2, the inner surface of the coating cavity 12 of the second mold 3 has a convex portion 30 corresponding to a desired pattern to be applied to the outer surface of the molding substrate 2, and the convex portion 30 is formed at a height H (see FIG. 9(a)) corresponding to the coating gap 4 (see FIG. 10(c)). The coating gap 4 is a gap formed between the outer surface of the molding substrate 2 and the inner surface of the coating cavity 12 of the second mold 3 when the abutment surface 6 of the first mold 1 in which the molding substrate 2 is attached to the coating core 10 is abutted against the abutment surface 7 of the second mold 3, as shown in FIG. 10(c). This coating gap 4 corresponds to the film thickness of the coating (paint) formed on the outer surface of the molding substrate 2 by the liquid coating agent 5 (paint). The coating cavity 12 shown in FIG. 2 is formed to be one size larger overall than the molding cavity 11, and the coating gap 4 shown in FIG. 10(c) is formed not only between the upper surface of the molding substrate 2 and the ceiling surface of the coating cavity 12, but also between the side surface of the molding substrate 2 and the side surface of the coating cavity 12.

As shown in FIG. 9(b), the first mold 1 with the molding substrate 2 attached to the coating core 10 is raised, and as shown in FIG. 10(c), when the butting surface 6 of the first mold 1 is butted against the butting surface 7 of the second mold 3, the molding substrate 2 attached to the coating core 10 of the first mold 1 is inserted into the coating cavity 12 of the second mold 3, and a part of the upper surface of the molding substrate 2 (the part where the desired pattern is applied) comes into contact with the convex portion 30 formed on the ceiling surface of the coating cavity 12. In this state, as shown in FIG. 10(d), when the liquid coating agent 5 (paint) is injected into the coating gap 4, the liquid coating agent 5 (paint) adheres to the outer surface of the molding substrate 2 other than the part where the convex portion 30 contacts, and the outer surface of the molding substrate 2 is coated with the liquid coating agent 5 (paint) except for the part with the desired pattern. In other words, the convex portion 30 functions as a masking member to prevent the liquid coating agent 5 (paint) from adhering to the outer surface of the molding substrate 2.

As shown in FIG. 4, the shape of the protrusion 30 is star-shaped in this embodiment, but it may be various shapes such as circles, triangles, squares, letters, alphabets, symbols, etc. according to the desired pattern to be applied to the outer surface of the molding substrate 2. If the shape of the protrusion 30 is partially or entirely ring-shaped (closed shape such as a square ring or a triangular ring), the liquid coating agent 5 (paint) cannot be introduced from the outside to the inside of the ring and the inside of the ring cannot be coated. Therefore, a part of the ring is cut off and the liquid coating agent 5 (paint) is introduced from the outside to the inside of the ring through the removed part to coat the inside of the ring. However, if the paint 5 (thermosetting paint) is a thermosetting resin, its viscosity is extremely low, so the width of the part of the ring to be removed is 0.1 mm or less, and the appearance that can be observed by the naked eye is not impaired.

The height H of the protrusion 30 shown in FIG. 9(a) may be equal to the coating gap 4 shown in FIG. 10(c), or may be slightly higher than the coating gap 4. When the height H of the protrusion 30 is slightly higher than the coating gap 4, as shown in FIG. 10(c), when the abutment surface 6 of the first mold 1 abuts against the abutment surface 7 of the second mold 3, the lower surface of the protrusion 30 is pressed against the upper surface of the molding substrate 2, causing the molding substrate 2 (made of resin) to elastically deform slightly, and the lower edge of the protrusion 30 slightly bites into the molding substrate 2. As a result, the masking function of the protrusion 30 is enhanced, and when the liquid coating agent 5 (paint) is injected into the coating gap 4 as shown in FIG. 10(d), the liquid coating agent 5 (paint) can be prevented from penetrating between the lower surface of the protrusion 30 and the upper surface of the molding substrate 2 against its will, resulting in poor masking. For example, if the coating gap 4 is 50 μm, the height of the protrusion 30 may be 50 μm, which is equal to the coating gap 4, or it may be 55 to 60 μm, which is 10 to 20% greater than the coating gap 4.

As shown in FIG. 4, the coating cavity 12 formed on the butting surface 7 of the second mold 3 and the convex portion 30 formed in the coating cavity 12 can be machined by electric discharge machining, machining using an end mill, or any other method. If machining is performed using a commercially available square end mill with a diameter of 0.2 mm and a cutting edge R of 0.05 mm, the step machining will be 0.05 mm or more if the film thickness of the liquid coating agent 5 (paint) (i.e., the coating gap 4) is 50 μm or more, so designs with sharp edges can be expressed and fine shapes can be machined to a level that cannot be recognized by the naked eye. The thicker the film, the easier it is to machine the mold and the clearer the contrast of the design shape, which increases the manufacturing margin and allows for stable production of quality.

(About each process)
The steps of the method for producing an in-mold coated molded product according to the first embodiment will be described below.

First, as shown in Figures 1(a) and 1(b), the butting surface 6 of the first mold 1 is butted against the butting surface 7 of the second mold 3, and resin (thermoplastic resin in this embodiment) is injected from the resin injection port 17. The resin passes through the sprue passage 16, the runner passage 20, and the gate 18, and is injected into the molding gap 15 formed between the molding core 9 and the molding cavity 11, where it cools and solidifies to become the molding substrate 2.

As shown in FIG. 2, the first mold 1 is separated from the second mold 3, and the molding substrate 2 attached to the molding core 9 is released by an ejection mechanism (not shown), and the sprue 25 and runner 26 are similarly released by an ejection mechanism (not shown). The runner 26 and the molding substrate 2 are separated at the gate 18.

As shown in Figures 3(a) and 3(b), in this embodiment, the molding substrate 2 is a cylinder with a capped top and an open bottom, but the shape is not limited to this and may be a rectangular parallelepiped or cube with an open bottom, or the bottom may not be open. Thereafter, as shown by arrow X in Figure 2, the molding substrate 2 released from the molding core 9 is attached to the painting core 10. The replacement of the molding substrate 2 is performed by a robot arm (not shown) or the like.

FIGS. 5 and 9(a) are explanatory diagrams showing the state immediately before the molding substrate 2 is attached to the coating core 10 of the first mold 1, and FIG. 6 and 9(b) are explanatory diagrams showing the state after the molding substrate 2 has been attached to the coating core 10 of the first mold 1. The molding substrate 2 may be attached to the coating core 10 by a suction function (not shown) provided within the coating core 10.

Next, as shown in Figures 7 and 10(c), the first mold 1 is moved closer to the second mold 3, and the abutment surface 6 of the first mold is abutted against the abutment surface 7 of the second mold 3. When this abutment is complete, a predetermined coating gap 4 (e.g., 50 μm) is formed between the outer surface of the molding substrate 2 attached to the coating core 10 of the first mold 1 and the inner surface of the coating cavity 12 of the second mold 3, and at the same time, the lower surface of the protrusion 30 formed on the ceiling surface of the coating cavity 12 comes into contact with the upper surface of the molding substrate 2 attached to the coating core 10, and this portion is masked.

That is, as shown in Figures 1(b) and 2, the paint cavity 12 is formed slightly larger than the molding cavity 11, and when the molded substrate 2 molded between the molding cavity 11 and the molding core 9 is attached to the paint core 10, and the paint cavity 12 is placed over the molded substrate 2 attached to the paint core 10 and the abutment surfaces 6, 7 are abutted against each other, a predetermined coating gap 4 is formed between the outer surface of the molded substrate 2 and the inner surface of the paint cavity 12, as shown in Figure 10(c). The coating gap 4 is formed not only between the top surface of the molded substrate 2 and the ceiling surface of the paint cavity 12, but also between the side of the molded substrate 2 and the side of the paint cavity 12.

At the same time as the coating gap 4 is formed in this manner, as shown in FIG. 10(c), the lower surface of the convex portion 30 formed on the ceiling surface of the coating cavity 12 comes into contact with the upper surface of the molding substrate 2 attached to the coating core 10, and the contacting portion is masked. Here, if the height H of the convex portion 30 shown in FIG. 9(a) is set to the same height as the coating gap 4 shown in FIG. 10(c), the convex portion 30 is masked in a state of contact with the molding substrate 2, and if the height H of the convex portion 30 is set to a height slightly higher than the coating gap 4 shown in FIG. 10(c), the convex portion 30 is pressed slightly against the molding substrate 2, and the lower edge portion of the convex portion 30 is masked in a state of slightly biting into the molding substrate 2, enhancing the masking effect.

Next, as shown in FIG. 10(d), liquid coating agent 5 (e.g., thermosetting paint 5) is injected from paint inlet 23. This paint 5 is injected into coating gap 4 through paint passage 22 and gate 21, hardens in coating gap 4, and adheres (coats) to the outer surface of molding substrate 2. At this time, paint 5 is not applied to the portions of the outer surface of molding substrate 2 that are masked by or slightly embedded in protrusions 30. Therefore, paint 5 is applied to the outer surface of molding substrate 2 except for the portions masked by protrusions 30.

After the paint 5 in the coating gap 4 has hardened, the first mold 1 is lowered and separated from the second mold 3, as shown in FIG. 11(e). At this time, the in-mold coated molded product 28 (product) in which the paint 5 has been coated on the outer surface of the molding substrate 2, except for the portion 31 masked by the protrusion 30, to form a coating film 27, is in a state of being fitted into the paint core 10. As shown in FIG. 11(f), the in-mold coated molded product 28 is released from the paint core 10 by an ejection mechanism (not shown).

Figure 12 shows an in-mold coated molded product 28 (product) in which a coating film 27 is formed on the outer surface of the molding substrate 2 except for the portion 31 that was masked by the protrusions 30. As shown in the figure, a coating film 27 of a coating agent (paint 5) is formed on the outer surface of the molding substrate 2, which is a cylinder with a capped top and an open bottom, except for the portion 31 that was masked by the protrusions 30. The thickness of the coating film 27 depends on the spacing of the coating gap 4 shown in Figure 10 (c).

(Action and Effects)
The method for producing the in-mold coated molded product 28 according to the first embodiment and the mold for the in-mold coated molded product used therein can provide the following effects.

In this embodiment, the manufacturing method for an in-mold coated molded product 28 is premised on the following: as shown in Figs. 9(a) and 9(b), the molded substrate 2 is attached to the painted core 10 of the first mold 1; as shown in Fig. 10(c), the abutting surface 6 of the first mold 1 is abutted against the abutting surface 7 of the second mold 3 to cover the molded substrate 2 with a painted cavity 12; a coating gap 4 is formed between the inner surface of the painted cavity 12 and the outer surface of the molded substrate 2; and as shown in Fig. 10(d), a liquid coating agent 5 (paint) is injected into the coating gap 4 to adhere to the outer surface of the molded substrate 2.

The feature of this embodiment is that, as shown in FIG. 4, the inner surface of the coating cavity 12 of the second mold 3 has a protrusion 30 corresponding to the desired pattern (star-shaped in this embodiment) to be applied to the outer surface of the molding substrate 2, which is formed at a height corresponding to the coating gap 4 shown in FIG. 10(c). As a result, as shown in FIG. 10(c), when the abutting surface 6 of the first mold 1 is abutted against the abutting surface 7 of the second mold 3 to form a coating gap 4 between the inner surface of the coating cavity 12 and the outer surface of the molding substrate 2, the protrusion 30 comes into contact with the outer surface of the molding substrate 2, and a part of the outer surface of the molding substrate 2 (the part to which the desired pattern (star-shaped in this embodiment) is to be applied) is masked by the protrusion 30. Here, by making the height H of the protrusion 30 shown in FIG. 9(a) slightly higher than the coating gap 4 shown in FIG. 10(c), when the abutting surface 6 of the first mold is abutted against the abutting surface 7 of the second mold 3, the protrusion 30 is pressed against the molding substrate 2 and slightly bites into it, thereby enhancing the masking effect.

As shown in FIG. 10(c), when the convex portion 30 is in contact with or pressed against the molding substrate 2, as shown in FIG. 10(d), liquid coating agent 5 (paint) is injected into the coating gap 4, so that the liquid coating agent 5 (paint) is applied to the outer surface of the molding substrate 2 other than the portion in contact with the convex portion 30. That is, the abutment surface 6 of the first mold 1 is abutted against the abutment surface 7 of the second mold 3, thereby simultaneously forming the coating gap 4 and masking with the convex portion 30, and the outer surface of the molding substrate 2 is coated with the liquid coating agent 5 (paint) except for the portion masked by the convex portion 30 (portion 31 of the desired pattern (star-shaped in this embodiment)). This allows the process of painting the outer surface of the molding substrate 2 and the process of forming the desired pattern on the outer surface of the molding substrate 2 to be performed simultaneously, shortening the manufacturing time and promoting cost reduction.

Note that the resin (resin used to make the molded substrate 2) injected into the resin injection port 17 shown in FIG. 1(b) may be a milky, transparent, semi-transparent, or colored transparent material that transmits light, and the liquid coating agent 5 (liquid coating agent applied to the outer surface of the molded substrate 2 except for the desired pattern area 31) injected into the paint injection port 23 shown in FIG. 10(d) may be a colored paint that does not transmit light. In this way, the in-mold coated molded product 28 shown in FIG. 12(a) can be used as a switch part that can be used in devices that are used in dark rooms, cars, or at night with little lighting, because when the main power is turned on, the light (not shown) on the back side turns on and the white area (white pattern (star-shaped design) area 31) emits light.

Furthermore, according to this embodiment, unlike the conventional examples (Patent Documents 2 and 3), the desired pattern portion of the coating applied to the entire outer surface of the molding substrate 2 is not removed with a laser beam, so there is no initial cost for introducing laser processing equipment. Furthermore, when removing the coating film of the desired pattern portion with a laser beam, it was necessary to make the coating film 27 as thin as possible (for example, 50 μm or less) to increase productivity, but in the present invention, the coating film 27 (see FIG. 12) is not removed with a laser beam, so there is no need to make the coating film 27 thin, and there is no cost for keeping the coating film 27 thin. The present invention is viable even if the coating film 27 is made to a certain thickness, and making it thicker improves the durability of the coating film 27 when used over time.

(others)
As shown in Fig. 2, the molding substrate 2 removed from the molding core 9 is attached to the coating core 10, and then, as shown in Fig. 10(c), the abutting surface 6 of the first mold 1 is abutted against the abutting surface 7 of the second mold 3 to form a coating gap 4 between the molding substrate 2 attached to the coating core 10 and the coating cavity 12, and the coating gap 4 is formed by masking with the convex portion 30. As shown in Fig. 1(b), the molding core 9 is inserted into the molding cavity 11 to form a molding gap 15 therebetween. Therefore, by performing the process of injecting the liquid coating agent (paint 5) into the coating gap 4 as shown in Fig. 10(d) and the process of injecting the resin into the molding gap 15 as shown in Fig. 1(b) in parallel, the molding of the molding substrate 2 and the coating of the paint 5 on the molding substrate 2 except for the masked portion can be performed simultaneously, improving the manufacturing efficiency.

In other words, the painted substrate 2 is ejected from the paint mold section 14 on the right side of FIG. 1(b), the molded substrate 2 molded in the molding mold section 13 on the left side is replaced with the paint core 10 on the right side, the first mold 1 and the second mold 3 are butted together, the liquid coating agent (paint 5) is applied to the substrate 2 in the paint mold section 14 on the right side except for the masked areas by the convex portions 30 to form a coating film 27, and the next substrate 2 is molded in the molding mold section 13 on the left side. By repeating this process, the molding of the substrate 2 and the coating of the substrate 2 except for the masked areas by the convex portions 30 can be performed simultaneously in one mold (the mating first mold 1 and second mold 3), improving manufacturing efficiency.

Second Embodiment
The second embodiment of the present invention will be described with reference to Figures 13 to 16. The premise of the manufacturing method of the in-mold coated molded product according to the second embodiment is basically the same as that of the first embodiment, and the molded substrate 2a obtained by injection molding as shown in Figures 13(a) and 13(b) is attached to the first mold 1 as shown in Figure 14(c), and the first mold 1 with the molded substrate 2a attached is butted against the second mold 3 as shown in Figure 14(d) so as to cover the molded substrate 2a, forming a coating gap 4a between the inner surface of the second mold 3 and the outer surface of the molded substrate 2a, and injecting a liquid coating agent 5 (paint, etc.) into the coating gap 4a as shown in Figure 15(e), and adhering it to the outer surface of the molded substrate 2a as shown in Figure 15(f).

The difference between the second embodiment and the first embodiment is that the convex portion 30 formed on the inner surface of the second mold 3 in the first embodiment as shown in Figure 9 (b) has been eliminated, and instead a convex portion 30a has been formed on the outer surface of the molding substrate 2a as shown in Figure 14 (c). That is, in the manufacturing method of the in-mold coated molded product according to the second embodiment, as shown in FIG. 13(a) and FIG. 13(b), the convex portion 30a corresponding to the desired pattern to be applied to the outer surface of the molding substrate 2a is formed on the outer surface of the molding substrate 2a at a height Ha corresponding to the coating gap 4a shown in FIG. 14(d). As shown in FIG. 14(c) and FIG. 14(d), when the first mold 1 to which the molding substrate 2a is attached is butted against the second mold 3 so as to cover the molding substrate 2a, the convex portion 30a formed on the outer surface of the molding substrate 2a contacts the inner surface of the second mold 3. As shown in FIG. 15(e), by injecting a liquid coating agent 5 (paint, etc.) into the coating gap 4a in this state, the liquid coating agent 5 is applied to the outer surface of the molding substrate 2a except for the portion where the convex portion 30a contacts the inner surface of the second mold 3. As shown in FIG. 15(f), the outer surface of the molding substrate 2a is coated (painted) with the liquid coating agent 5 except for the portion of the desired pattern (convex portion 30a) to form a coating film 27, and the in-mold coated molded product 28a (see FIG. 16) is manufactured.

The mold for in-mold coated molded products used in the manufacturing method for in-mold coated molded products 28a according to the second embodiment has many components similar to those of the mold for in-mold coated molded products used in the manufacturing method for in-mold coated molded products 28 (see FIG. 12) according to the first embodiment, so the same reference numerals are used for the similar components and their explanations are omitted, and only the differences will be described.

As shown in Figures 13(a) and 13(b), a recess 32 is formed on the ceiling surface of the molding cavity 11 for forming a protrusion 30a on the top surface of the molding substrate 2a. The protrusion 30a formed by the recess 32 has a shape according to the desired pattern to be applied to the outer surface of the molding substrate 2a, and in this embodiment is a star shape as shown in Figure 16, but is not limited to this and may be various shapes according to the desired pattern, such as a circle, a triangle, a square, a letter, an alphabet, or a symbol. On the other hand, the recess 32 is formed by inverting the unevenness of the protrusion 30a, as shown in Figures 13(a) and 13(b).

As shown in Figure 13(a), the position of the deepest part of the recess 32 (height in the case of vertical clamping) coincides with the ceiling surface of the paint cavity 12, as shown by the dashed line. As a result, when the molding substrate 2a is transferred from the molding core 9 to the paint core 10 as shown in Figure 13(b), and the first mold 1 is butted against the second mold 3 as shown in Figures 14(c) and 14(d), the top surface of the protrusion 30a of the molding substrate 2a attached to the paint core 10 comes into contact with the ceiling surface of the paint cavity 12, and the contacting portion is masked. In addition, in FIG. 13(a), by positioning the deepest part of the recess 32 slightly higher than the ceiling surface of the paint cavity 12, when the first mold 1 is butted against the second mold 3, as shown in FIG. 14(c) and FIG. 14(d), the protrusion 30a of the molding substrate 2a attached to the paint core 10 is pressed against the ceiling surface of the paint cavity 12 and slightly compressed, and the restoring force presses the protrusion 30a against the ceiling surface of the paint cavity 12, enhancing the masking effect.

With the protrusion 30a in contact with or pressed against the ceiling surface of the coating cavity 12 in this manner, as shown in FIG. 15(e), a liquid coating agent 5 (paint, etc.) is injected into the coating gap 4a from the paint injection port 23. The liquid coating agent 5 then adheres to the outer surface of the molding substrate 2a, except for the portion masked by the protrusion 30a in contact with or pressed against the ceiling surface of the coating cavity 12. Then, as shown in FIG. 15(f), the first mold 1 is separated from the second mold 3, and the in-mold coated molded product 28a (product) fitted into the coating core 10 is demolded by an ejection mechanism (not shown) provided on the coating core 10.

16(a) and 16(b) show an in-mold coated molded product 28a (product) manufactured by the second embodiment. As shown in the figure, a coating film 27 of a coating agent (paint 5) is formed on the outer surface of the molding substrate 2a, which is a cylinder with a covered top and an open bottom, except for the protruding portion 30a that was in contact with or pressed against the ceiling surface of the coating cavity 12 when the mold was clamped. The height Ha of the protruding portion 30a shown in FIG. 14(c) is formed to a height corresponding to the coating gap 4a shown in FIG. 14(d), so that the surface of the coating film 27 and the top surface of the protruding portion 30a are flush with each other, which is different from the product of the first embodiment (see FIG. 12). The thickness of the coating film 27 is a thickness corresponding to the spacing of the coating gap 4a shown in FIG. 14(d).

In the second embodiment, the side that is masked by the convex portion 30a is reversed from the first embodiment, but the basic technical concept is the same as in the first embodiment. Therefore, the action and effect of the second embodiment are basically the same as in the first embodiment, and a description thereof will be omitted.

The above describes a preferred embodiment of the present invention with reference to the attached drawings, but it goes without saying that the present invention is not limited to the above-mentioned embodiment, and various modified or altered examples within the scope of the claims also fall within the technical scope of the present invention. For example, the present invention also includes an embodiment in which the first embodiment and the second embodiment are superimposed, in which the masking side and the masked side are reversed.

The present invention can be used in a method for manufacturing an in-mold coated molded product in which a coating gap is formed between the outer surface of a substrate sandwiched between a pair of molds and the inner surface of the molds, and a liquid coating agent (paint) is injected into the coating gap to adhere to the outer surface of the substrate, and in a mold for an in-mold coated molded product used in the method, in which a desired pattern is formed by preventing the liquid coating agent from adhering to desired locations on the outer surface of the substrate, and in a mold for an in-mold coated molded product used in the method.

1 First mold 2 Molding substrate 2a Molding substrate (Second embodiment)
3 Second mold 4 Coating gap 4a Coating gap (second embodiment)
5 Liquid coating agents (e.g. paints)
6: Abutment surface of first mold 7: Abutment surface of second mold 9: Molding core 10: Paint core 11: Molding cavity 12: Paint cavity 27: Paint film 28: In-mold coated molded product 28a: In-mold coated molded product (second embodiment)
30 Convex portion 30a Convex portion (second embodiment)
31: Part of desired pattern H: Height of convex portion 30 Ha: Height of convex portion 30 (second embodiment)

Claims

A method for producing an in-mold coated molded product, comprising the steps of: mounting a molding substrate in a first mold; abutting the first mold with the mounting substrate against a second mold so as to cover the molding substrate; forming a coating gap between an inner surface of the second mold and an outer surface of the molding substrate; and injecting a liquid coating agent into the coating gap to adhere the coating agent to the outer surface of the molding substrate,
A method for producing an in-mold coated molded product, characterized in that convex portions corresponding to a desired pattern to be applied to the outer surface of the molding substrate are formed on the inner surface of the second mold at a height corresponding to the coating gap, and when the first mold with the molding substrate attached is abutted against the second mold so as to cover the molding substrate, the convex portions formed on the inner surface of the second mold come into contact with the outer surface of the molding substrate, and in this state, the liquid coating agent is injected into the coating gap to adhere the liquid coating agent to the outer surface of the molding substrate other than the area where the convex portions come into contact, and the outer surface of the molding substrate is coated with the liquid coating agent except for the area with the desired pattern.
The method for manufacturing an in-mold coated molded product according to claim 1, characterized in that the convex portion formed on the inner surface of the second mold is formed to a height slightly higher than the coating gap, and when the first mold with the molding substrate attached is butted against the second mold so as to cover the molding substrate, the convex portion formed on the inner surface of the second mold is pressed against the outer surface of the molding substrate, thereby preventing the liquid coating agent from penetrating between the convex portion and the outer surface of the molding substrate when the liquid coating agent is injected into the coating gap.
A method for producing an in-mold coated molded product, comprising the steps of: mounting a molding substrate in a first mold; abutting the first mold with the mounting substrate against a second mold so as to cover the molding substrate; forming a coating gap between an inner surface of the second mold and an outer surface of the molding substrate; and injecting a liquid coating agent into the coating gap to adhere the coating agent to the outer surface of the molding substrate,
a method for producing an in-mold coated molded product, characterized in that: convex portions corresponding to a desired pattern to be applied to the outer surface of the molding substrate are formed on the outer surface of the molding substrate at a height corresponding to the coating gap; when the first mold with the molding substrate attached is abutted against the second mold so as to cover the molding substrate, the convex portions formed on the outer surface of the molding substrate come into contact with the inner surface of the second mold; and in this state, the liquid coating agent is injected into the coating gap to adhere the liquid coating agent to the outer surface of the molding substrate other than the portion contacted by the convex portions, thereby coating the outer surface of the molding substrate with the liquid coating agent except for the portion with the desired pattern.
The method for manufacturing an in-mold coated molded product according to claim 3, characterized in that the convex portion formed on the outer surface of the molding substrate is formed to a height slightly higher than the coating gap, and when the first mold to which the molding substrate is attached is butted against the second mold so as to cover the molding substrate, the convex portion formed on the outer surface of the molding substrate is pressed against the inner surface of the second mold, thereby preventing the liquid coating agent from penetrating between the convex portion and the outer surface of the molding substrate when the liquid coating agent is injected into the coating gap.
The method for manufacturing an in-mold coated molded product according to any one of claims 1 to 4, characterized in that a thermosetting paint is used as the liquid coating agent, the thermosetting paint is injected into a coating gap formed between the inner surface of the second mold and the outer surface of the molding substrate, and then the thermosetting paint is hardened by a thermal reaction using the second mold as a heat source and adheres to the outer surface of the molding substrate.
A mold for an in-mold coated molded product used in the method for producing an in-mold coated molded product according to claim 1,
A mold for in-mold coated molded products, characterized in that a convex portion corresponding to a desired pattern to be applied to the outer surface of the molding substrate is formed on the inner surface of the second mold at a height corresponding to the coating gap, and when the first mold with the molding substrate attached is abutted against the second mold so as to cover the molding substrate, the convex portion formed on the inner surface of the second mold comes into contact with the outer surface of the molding substrate.
A mold for an in-mold coated molded product used in the method for producing an in-mold coated molded product according to claim 2,
A mold for in-mold coated molded products, characterized in that a convex portion corresponding to a desired pattern to be applied to the outer surface of the molding substrate is formed on the inner surface of the second mold at a height slightly higher than the coating gap, and when the first mold with the molding substrate attached is abutted against the second mold so as to cover the molding substrate, the convex portion formed on the inner surface of the second mold is pressed against the outer surface of the molding substrate.