JP2003159724A - Method for coating and molding inside of mold - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for coating and molding the inside of a mold, which allows a coating to be easily applied by using a porous material such as a real-grain veneer as a skin material, and allows a coating film for extending a function of the skin plate to be formed by using an extremely small number of man-hours. <P>SOLUTION: A resinous base material 1 is integrally molded on the backside of the skin material 3; next, a gap 43 is formed by spacing a surface of the skin material 3 and a mold surface; and the mold is heated while being closed for pressurization, after the injection of a thermosetting coating into the gap 43. Since the coating is pressed from a surface side by a pressure force, flix and foaming are regulated; and since the coating film is heated for curing in such a state, the smooth and fine coating film can be formed. Additionally, the use of the coating allows the avoidance of the action of a high temperature on a designed surface of the skin material in contrast to a case in which a resin layer is formed by molding. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

The present invention relates to a method of forming a coating film in a mold. INDUSTRIAL APPLICABILITY The molding method of the present invention is extremely useful for manufacturing automobile interior parts and the like having the design of the heather.

[0001]

2. Description of the Related Art Interior parts such as instrument panels, center clusters, and console uppers for automobiles have a skin material preliminarily formed into a predetermined shape, which is placed on the mold surface of a mold, and the back surface side of which is made of resin by injection molding. It is manufactured by a manufacturing method of integrally molding a base material. According to this manufacturing method, it is possible to save the labor of attaching the skin material to the resin base material, and to significantly reduce the number of steps.

However, in recent years, for the purpose of imparting a high-class feeling, a veneer-made veneer may be used as a skin material for interior parts of automobiles. When the veneer made of this heather is exposed on the surface, stains and discoloration occur, so it is necessary to paint the surface as in the case of furniture. However, in order to beautifully coat a single sheet made of heather, a coating film for preventing suction is formed, and after hardening, a coating film for polishing is formed and polished to remove fluff and smooth the surface. However, an extremely large number of man-hours such as forming a colored coating film and a clear coating film on the surface is required, and this coating process is a big problem for reducing the man-hours.

Japanese Patent Laid-Open No. 30922/1993 discloses a technique of injection molding synthetic resin on both sides of a wood decorative board. According to this technique, the surface of the wood decorative board can be protected by injection-molding the transparent resin at least on the surface side of the wood decorative board, and a design with a realistic wood texture can be formed. And since it can be manufactured only by two injection molding steps, the number of steps is small.

Further, in Japanese Unexamined Patent Publication No. 2001-170964, a synthetic resin skin material is arranged on the mold surface of a mold, and a resin base material is injection-molded on one surface side thereof, and then the other surface side of the skin material is formed. There is disclosed an in-mold coating molding method of injecting a paint between the mold surface and the mold surface and applying pressure to form a coating film on the other surface side of the skin material. According to this method, both surfaces of the skin material are formed of a material having excellent adhesion to the resin base material or the coating film, respectively, so that even if a coating material having poor adhesion to the resin base material is used. A coating film having excellent adhesion can be formed on the surface of the resin substrate.

[0005]

By the way, in the case of injection molding, if the space between the mold surfaces is too narrow, it becomes difficult for the resin to flow, so that a certain space or more is required. Therefore, in the technique disclosed in Japanese Patent Laid-Open No. 30922/1993, the thickness of the synthetic resin layer on the surface side of the wood decorative board becomes too thick, and the wood decorative board is damaged as if it were made of plastic. There is a defect.

Further, Japanese Patent Laid-Open No. 2001-170964 only discloses the use of a synthetic resin skin material, and the function of the skin material is never expanded by the formed coating film. There is no description. Furthermore, it is known that various problems such as suction of paint into the porous material, fluffing, and foaming from pores occur when ordinary coating is applied to a porous material such as a single heather. There is. Therefore, JP 20
It is considered that the same problem may occur when the skin material described in JP-A No. 01-170964 is replaced with a porous material such as a single plate made of this heather, and JP-A No. 2001-170964 discloses such a case. There is no suggestion of how to solve the problem.

The present invention has been made in view of the above circumstances, and a porous material such as a single plate made of this heather can be used as a skin material for easy coating, and the function of the skin material can be improved. The purpose is to form a coating film that expands with a very small number of steps.

[0008]

The features of the in-mold coating molding method of the present invention for solving the above-mentioned problems are that a porous skin material is placed in a mold and a resin base material is provided on the back surface of the skin material. The first step of integrally molding, the gap between the surface of the skin material and the mold surface is opened to form a gap, the thermosetting paint is injected into the gap, and then the mold is closed and heated while pressurizing the skin material. The second step is to form a coating film on the surface for expanding the function of the skin material.

The skin material is a wood decorative board, and the coating film is preferably transparent. In this case, it is preferable that a transparent colored layer is previously formed on the wood decorative board. It is also preferable that the skin material is a soft foam.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION In the mold coating method according to the present invention, in the second step, a gap is formed by opening the surface of the porous skin material and the mold surface, and the gap is thermosettable. After injecting the paint, the mold is closed and heated while being pressurized to form a coating film that extends the function of the skin material on the surface of the skin material.
At this time, the paint is pressed into the pores of the porous skin material by the force of pressure and enters the pores. Then, when the skin material is a single plate made of this heather, the fluffing and the air in the conduit tend to become bubbles, but since the paint is pressed from the surface side by the pressing force, Fluffing and foaming are regulated. Since the coating film is heated and cured in that state, a smooth and beautiful coating film can be formed.

Further, since the coating film is formed by the paint, unlike the case where the resin layer is formed by molding, high temperature is prevented from acting on the design surface of the skin material. Therefore, problems such as discoloration, deformation or carbonization of the skin material do not occur.

Further, if a grain pattern or the like is formed on the mold surface in contact with the paint, the pattern is transferred to the coating film, so that various pattern coating films can be formed.

In the first step, a porous skin material is placed in a mold, and a resin base material is integrally molded on the back surface of the skin material. As the skin material, it is preferable to use a single plate, a veneer plate or the like made of Honji, but it is also possible to use a soft foam such as a sponge. The resin base material reinforces the skin material and can be formed from various synthetic resins such as ABS, PP, PE, polyester and nylon by injection molding or compression molding. The molding conditions may be the same as those of the conventional integral molding.

When the skin material is a single plate made of this heather and the product has a complicated shape, it is desirable to preliminarily shape it into a predetermined shape by heating and humidifying. In the case of a soft foam such as urethane foam, it may be shaped into a predetermined shape at the time of molding, or may be shaped at the time of molding a resin base material.

Since the skin material is porous, the molten resin intrudes into the pores to obtain high adhesiveness due to the anchor effect, but the back surface side of the skin material does not adhere to the resin base material. It is also possible to form a high adhesive layer. Examples of the adhesive layer include a layer made of non-woven fabric, a thin wooden board, or the like.

In the second step, first, a gap is formed by opening the surface of the skin material and the mold surface. In many cases, bosses, ribs, etc. are formed on the back surface side of the resin base material for the purpose of attachment or reinforcement, and since the surface area is larger than the front surface side, the resin base material tends to adhere to the mold surface. Therefore, by simply opening the movable die and the fixed die, the resin base material covered with the skin material is taken by the movable die, so that a gap can be easily formed between the surface of the skin material and the die surface. it can.

In the second step, next, the thermosetting paint is injected into the created gap. As this thermosetting paint, urethane resin paint, amino resin paint, epoxy resin paint,
Although various synthetic resin paints such as unsaturated polyester resin paints can be used, a high solid paint containing almost no solvent and having a high solid content is particularly desirable. Further, it is desirable to use a material to which an ultraviolet absorber, an antioxidant, a gloss imparting agent, etc. are added, as in the case of the conventional paint. As such a thermosetting paint, for example, the paint described in JP-A-2001-170964 can be used.

Since the viscosity of the coating material is lower than the viscosity of the molten resin at the time of injection molding, the injection pressure can be extremely small and can be easily injected even if the gap is narrow. It is also preferable to heat the paint to some extent to reduce the viscosity.

After a predetermined amount of paint is injected into the gap, the mold is closed and the paint is heated while being pressed between the mold surface and the skin material. This causes the paint to enter the pores of the skin material. At this time, if the skin material is a single plate made of this heather, the fluffing and the air in the conduit tend to become bubbles, but since the paint is pressed from the surface side by the pressing force. Fluffing and foaming are regulated.

Since the viscosity of the coating material is low, the above-mentioned pressing force does not require a high force as in injection molding, and a small force of about 3 to ²⁰ kg / cm ² is sufficient. Of course, the same pressure force as in injection molding may be used. Then, the coating material is cured by heating while applying pressure, and a coating film having a beautiful surface with no irregularities is formed in which the mold surface is transferred to the surface of the skin material. When a pattern such as grain is formed on the mold surface, a coating film to which the pattern is transferred is formed. The heating temperature and time are determined according to the type of paint used.

The thickness of the coating film is not particularly limited, but it is preferably about several tens of μm to 100 μm as in general coating.
If it is thicker than 100 μm, the realism of the wood decorative board is lost and the design is deteriorated.

When the skin material is a wood decorative board such as a veneer made of Honjo, it is desirable to use a clear paint as the paint to form a transparent coating film. As a result, the grain of wood is exposed and the design of the heather is further improved due to the wet color. Since the coating film can prevent discoloration and fading, stains, etc., a high design can be maintained for a long period of time. Therefore, the function of the wood decorative board can be expanded by the coating film. It is also possible to add a glittering material such as mica pigment to the clear coating material to such an extent that transparency is not impaired.

When a transparent coating film is formed, it is preferable to previously form a transparent colored layer on the wood decorative board. As a result, it is possible to alleviate the color unevenness of the wood decorative board, and it is possible to achieve a design color tone that matches the surroundings to which the product is attached. The transparent colored layer may be formed by directly coloring the wood decorative board with a dye or a transparent pigment, or by applying a transparent colored paint.

When the skin material is a soft foam, the paint is preferably an opaque colored paint, and it is desirable to form a soft coating film such as urethane resin paint. As a result, the coating film can be deformed as the skin material elastically deforms, and the pores of the skin material are not exposed, resulting in a smooth surface, which significantly improves the designability of the skin material and softens the skin material. The tactile feeling can be maintained, and the function of the skin material can be expanded.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples.

FIG. 1 is a cross-sectional view of the essential parts of the console upper manufactured by the in-mold coating molding method of this embodiment. This console upper includes a resin base material 1, an adhesive layer 2, and a veneer-made single plate 3 joined to the resin base material 1 by the adhesive layer 2.
It is composed of a clear coating film 4 formed on the surface of the single plate 3.

First, a mold composed of a fixed mold 40 and a movable mold 41 shown in FIG. Placed on the surface. The veneer 3 was arranged such that the surface serving as the design surface faces the mold surface of the fixed mold 40. The veneer 3 is colored yellow with a dye in advance, and a non-woven fabric is attached to the back surface of the veneer 3 via an acrylic or urethane adhesive to form the adhesive layer 2.

Next, as shown in FIG. 3, a fixed die 40 and a movable die 41.
The mold was clamped, and molten ABS was injected from the tunnel gate 42 of the movable mold 41 at an injection pressure of 100 kg / cm ² . The molten resin filled the cavity formed between the single plate 3 and the movable die 41, and the resin base material 1 was formed. The veneer 3 is integrally bonded to the resin base material 1 by the adhesive layer 2.

After the resin base material 1 was cooled and solidified, the fixed mold 40 and the movable mold 41 were opened by about 0.4 mm as shown in FIG. The resin base material 1 has a boss or rib (not shown) formed on the mold surface of the movable mold 41 on the back surface side. Therefore, the area in contact with the movable die 41 is large, and the resin base material 1 moves together with the single plate 3 while being attached to the movable die 41. As a result, a gap 43 having a width of about 0.3 mm is formed between the single plate 3 and the mold surface of the fixed mold 40.

In this state, clear paint consisting of urethane resin paint is made to leave a gap from the paint injection machine 5 provided on the fixed mold 40.
Then, as shown in FIG. 5, the fixed mold 40 and the movable mold 41 were clamped at a pressure of about 150 Kg / cm ² immediately after that. The injection time is about 1.5 seconds. The stationary die 40 was heated by the heater 44 provided in the stationary die 40 so that the die surface temperature became 100 ° C.

The paint used here is a cream-like ultra-high solid urethane resin paint with a solid content of about 100% by weight, and a microencapsulated catalyst is added.
The paint flows into the cavity through the mold and is injected into the gap 43. The paint injected into the gap 43 spreads evenly under pressure to a film thickness of 40 μm, and because the microcapsules are destroyed to exert a catalytic action, it is rapidly cured by heating at 100 ° C. for 90 seconds, and a clear coating is applied. The film 4 was formed.

After the mold was opened, the molded product was released from the mold and burrs were cut off to obtain a console upper. The obtained console upper has a high rigidity due to the resin base material 1, and a smooth clear coating film having a film thickness of 40 μm is integrally formed on the surface of the veneer 3. It showed high designability due to the color tone of the wet color.

[0033]

[Effects of the Invention] That is, according to the in-mold coating molding method of the present invention, a porous material such as a veneer made of this heather can be used as a skin material for easy coating, and the function of the skin material is It is possible to form a coating film that expands with a very small number of steps.

[Brief description of drawings]

FIG. 1 is an enlarged cross-sectional view of a main part of a console upper obtained in an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a mold showing a state in which a skin material is arranged in one embodiment of the present invention.

FIG. 3 is a cross-sectional view of a mold showing a state immediately after molding a resin substrate in one example of the present invention.

FIG. 4 is a cross-sectional view of a mold showing a state in which a resin base material is molded and then slightly opened to form a gap in one embodiment of the present invention.

FIG. 5 is a cross-sectional view of a mold showing a state immediately after forming a clear coating film in one example of the present invention.

[Explanation of symbols]

1: Resin base material 2: Adhesive layer 3: Single plate (skin material) 4: Clear coating film 43: Gap

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kenji Sugiyama             Aichi Prefecture Kasuga-cho, Nishikasugai-gun Ochiai character Nagahata 1             Address within Toyoda Gosei Co., Ltd. F term (reference) 4F206 AD06 AD08 AD11 AD17 AG03                       AH25 AH26 JA07 JB13 JB28                       JF05 JF06 JN25 JN35

Claims (4)

[Claims] 1. A first step of arranging a porous skin material in a mold and integrally molding a resin base material on the back surface of the skin material; and opening the surface of the skin material and the mold surface. Second step of forming a gap on the surface of the skin material by injecting a thermosetting paint into the space and then heating the mold while closing the mold and applying pressure And an in-mold coating forming method. 2. The in-mold coating molding method according to claim 1, wherein the skin material is a wood decorative board, and the coating film is transparent. 3. The in-mold coating molding method according to claim 2, wherein a transparent colored layer is previously formed on the wood decorative board. 4. The skin material is a soft foam.
In-mold coating molding method according to.