JP2005288739A - Method and mold for in-mold coating molding - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-mold coating molding method which can suppress the defective molding of a coating film by residual air in a cavity and a mold for in-mold coating molding. <P>SOLUTION: With regard to the mold 30 for in-mold coating molding, a second cavity 35 for molding a coating film is formed by interchanging from a substrate molding mold to a coating film molding mold 33 in relation to a first mold 31 and mold clamping. A gas injection hole 41 for charging an inert gas, a coating injection hole 43 for injecting coating, and an air discharge hole 42 for discharging air are formed in the coating film molding mold 33. The coating injection hole 43 is arranged on the air discharge hole 42 side from the gas injection hole 41. Into the second cavity 35, the inert gas is charged and the coating is injected after the air is pushed out. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an in-mold coating molding method and an in-mold coating molding die for producing a resin molded product having a coating film on the surface of a base material such as an automobile part.

Conventionally, an in-mold coating molding method has been studied in which a resin molded product having a coating film on the surface of a substrate is molded in a cavity of a mold. In this in-mold coating molding method, a coating film is molded on the surface of the substrate by filling the cavity with the coating material. As the paint, an anaerobic material made of a thermosetting resin is mainly used, and it tends to be uncured in the presence of air. Therefore, a method for accelerating the curing of the paint by replacing the air in the cavity with an inert gas such as nitrogen gas, helium gas, or argon gas or making the inside of the cavity a vacuum has been proposed (for example, Patent Literatures 1 to 3). In this in-mold coating molding method, the inert gas is injected after the mold is filled with a paint in a state where the in-mold coating molding die is slightly opened (opened). In addition, a method is also shown in which an air compressor or the like is connected to a mold for in-mold coating molding and the mold is evacuated after the mold is clamped.
JP 63-128918 A JP 63-178018 A JP-A-1-215519

  However, in the conventional injection of the inert gas, when the in-mold coating mold is opened and the paint is filled, air tends to be mixed and remain in the paint. On the other hand, in the method of evacuating the inside of the mold, providing an air compressor or the like tends to make the mold for in-mold coating molding large, and it is not always possible to evacuate reliably. It tends to remain. Furthermore, a method of injecting an inert gas in a vacuum state in the mold is also conceivable, but in this case, there is a high possibility that the remaining air is confined in the mold with the inert gas. Therefore, in these conventional in-mold coating molding methods and in-mold coating molding dies, the paint is hard to be hardened by the air remaining in the mold, and coating film molding is liable to occur.

  The present invention has been made paying attention to such problems existing in the prior art. An object of the present invention is to provide an in-mold coating molding method and an in-mold coating molding die capable of suppressing poor molding of a coating film due to air remaining in a cavity.

  In order to achieve the above object, the invention of an in-mold coating molding method according to claim 1 is a substrate for molding the substrate in a first cavity formed by the first mold and the second mold. A coating process for forming the coating film from an anaerobic coating in a second cavity formed by the base material, the first mold and the second mold, and the coating film forming process Includes a press-fitting step of injecting an inert gas into the second cavity from a gas injection hole provided in the second mold, and air in the second cavity from an air discharge hole provided in the second mold. An exhaust stage for exhausting by injecting the inert gas, and the inert gas from the paint injection hole provided in the second mold or the first mold so as to be positioned between the gas injection hole and the air exhaust hole. The paint is filled into the second cavity in the presence of gas. And summarized in that and a filling step of.

  In the invention with the above configuration, the air in the second cavity is pushed toward the air discharge hole by the inert gas press-fitted into the second cavity in the press-fitting stage, and is pushed out from the air discharge hole to the outside in the exhaust stage. It is. In addition, since the paint injection hole is provided between the gas injection hole and the air discharge hole, the space from the paint injection hole to the air discharge hole, that is, the paint is filled in the second cavity in the filling stage. The space is preferably replaced with air by an inert gas. As a result, it is possible to suppress the remaining of air in the space filled with the paint in the second cavity in the filling stage, and it is possible to suppress the molding failure of the coating film due to the remaining of air.

  According to a second aspect of the present invention, there is provided the in-mold coating molding method according to the first aspect, wherein the second mold includes a base material mold that forms the first cavity together with the first mold, and the first mold. A coating mold for forming the second cavity together with one mold, and the coating mold from the base mold to the first mold between the base molding step and the coating molding step. The gist of the present invention is to provide a mold exchanging step for exchanging it.

  In the conventional in-mold coating molding method, the second cavity is formed by sliding the second mold relative to the first mold in the mold opening or clamping direction (mold opening / closing direction). For this reason, in the conventional in-mold coating molding method, when the second mold is slid in the mold opening / closing direction, a gap is easily formed in the mold, and air easily enters. On the other hand, in the invention having the above configuration, since the first mold is replaced from the base mold to the coating film mold, formation of a gap in the mold can be suppressed. As a result, it is possible to suitably push out the air in the second cavity by injecting the inert gas, and it is possible to suppress the air from entering the second cavity again from the gap.

  According to a third aspect of the present invention, there is provided an in-mold coating mold according to the first or second aspect, wherein the coating film forming step is performed after the exhausting step and before the filling step. Alternatively, the present invention includes a closing step of closing the air discharge hole with the base material during the filling step.

  In the invention with the above configuration, the air discharge hole is closed at the closing stage, so that the paint can be prevented from entering the air discharge hole, and the clogging of the air discharge hole due to the hardened paint can be reduced. Can do.

  The invention for a mold for in-mold coating molding according to claim 4 is a mold for in-mold coating molding for molding a resin molded product having a coating film on the surface of a substrate, wherein the first mold and the second mold are used. And the substrate is molded in a first cavity formed by the first mold and the second mold, and the second cavity formed by the first mold, the second mold and the substrate is formed in the second cavity. The second mold or the first mold is configured so that the coating film is formed by filling and curing an anaerobic paint from a paint injection hole provided in the first mold. A gas injection hole for injecting an inert gas into the second cavity and an air discharge hole for discharging the air in the second cavity are provided so as to open at the cavity surface of the second mold, respectively, The paint injection hole between the gas injection hole and the air discharge hole And gist being disposed.

  In the invention with the above configuration, the air in the second cavity is pushed toward the air discharge hole by the inert gas press-fitted from the gas injection hole, and is pushed out from the air discharge hole in the exhaust stage. Since the paint injection hole is provided between the gas injection hole and the air discharge hole, the space filled with the paint from the paint injection hole to the air discharge hole is preferably changed from air to an inert gas. Will be replaced. As a result, it is possible to suppress the remaining of air in the space filled with the paint in the second cavity, and it is possible to suppress the molding failure of the coating film due to the remaining of air.

  The invention for an in-mold coating mold according to claim 5 is the invention according to claim 4, wherein the second mold includes a base material mold and a coating film mold, and the first mold and The gist is that a first cavity is formed by the base material mold, and a second cavity is formed by the first mold and the coating film mold.

  In the conventional mold for in-mold coating molding, the second cavity is formed by sliding the second mold in the mold opening / closing direction with respect to the first mold. For this reason, the conventional mold for in-mold coating molding has a structure in which the second mold can be slid in the mold opening / closing direction, so that a gap is easily formed in the mold and air can easily enter. On the other hand, in the invention having the above configuration, the first cavity and the second cavity are formed by replacing the first mold with the base mold and the coating film mold. ing. As a result, the formation of a gap in the mold can be suppressed, and the air in the second cavity can be suitably pushed out by the press-fitting of the inert gas, and the air again enters the second cavity from the gap. It can suppress entering.

  According to a sixth aspect of the present invention, there is provided the mold for in-mold coating molding according to the fourth or fifth aspect, wherein the first mold is positioned so as to be opposed to the air discharge hole. The gist is that a pressing member that presses the substrate toward the air discharge hole is provided so as to protrude from the cavity surface of the first mold.

  In the invention of the above configuration, the air discharge hole can be closed by the substrate pressed toward the air discharge hole, and the paint is prevented from entering the air discharge hole, and the air discharge hole by the hardened paint Clogging can be reduced.

  The invention for an in-mold coating mold according to claim 7 is the invention according to any one of claims 4 to 6, wherein the inner surface of the gas injection hole is directed toward the opening side. The gist is that it is formed in a taper shape that expands.

  In the invention of the above configuration, the pressure applied to the inner surface of the gas injection hole by the inert gas pushed back to the gas injection hole by the paint can be made higher than the pressure at which the paint tries to enter the gas injection hole. As a result, it is possible to suppress the paint from entering the gas injection hole, and to reduce clogging of the gas injection hole by the hardened paint.

  According to the present invention, it is possible to provide an in-mold coating molding method and an in-mold coating molding die capable of suppressing a molding defect of a coating film due to air remaining in a cavity.

Hereinafter, an embodiment in which the present invention is embodied in an in-mold coating molding die and an in-mold coating molding method for molding a garnish for an automobile door pillar will be described with reference to the drawings.
First, garnish as a resin molded product will be described.

  As shown in FIGS. 1A and 1B, the garnish 11 is formed in a thin plate shape from a base body 12 and a coating film 13 formed on the surface of the base body 12. The base body 12 is made of a thermoplastic resin. The coating film 13 is formed from an anaerobic paint made of a thermosetting resin. The garnish 11 is attached with the surface on which the coating film 13 is provided on the door pillar portion of the door of the automobile as a design surface and the consent design surface facing the outside of the vehicle. Moreover, the coating film 13 in the drawing is drawn with exaggerated thickness.

  The garnish 11 has a first tab 14 at the base end (lower end in FIG. 1A) in a state after being removed from the mold for in-mold coating molding, and the distal end (FIG. 1B). ) In the upper end). The first tab 14 and the second tab 16 are surplus portions that are separated from the garnish 11 at the time of shipment, use, and the like, and constitute the base material 12 a together with the base material body 12. The form of the surplus portion is different for each resin molded product, and in addition to the garnish 11 where the surplus portion is composed only of tabs, a resin molded product having a surplus portion generally called “runner”, a runner There is a resin molded product having both a tab and a tab.

  Here, the paint will be described. In this embodiment, an acrylic heat-promoted radical reaction type paint is used. In this paint, an additive substance called an initiator (here, peroxide) is radically cleaved by heating, and the generated radical molecules react with acrylic monomers contained in the paint to generate acrylic radicals. By causing an addition polymerization reaction in a chain, the film is cured to form a coating film. When triplet state oxygen is present in the air at the time of curing of the paint, the oxygen is also a radical molecule, easily reacting with the acrylic radical, and forms a state expressed as ROO. Resulting in. Since this ROO · has a very low reactivity compared to the acrylic radical, the addition polymerization reaction hardly occurs in a chain, and becomes a relatively stable peroxide and stops the addition polymerization reaction. Therefore, in the presence of air, particularly oxygen, the reaction rate of the addition polymerization reaction in the coating is reduced, the coating film is likely to be uncured, and defective molding occurs. Therefore, the coating film 13 is molded using an in-mold coating molding die by replacing the air with an inert gas such as nitrogen gas, helium gas, neon gas, argon gas, krypton gas, xenon gas, etc. Performed in the presence of gas.

  The garnish 11 in the state after demolding has traces of the thermoplastic resin injection hole, the paint injection hole, the inert gas injection hole, and the air discharge hole forming the substrate 12a. doing. In addition, these traces are left in the surplus part in order to ensure the designability of the garnish 11. That is, the first tab 14 has on its surface a gas injection trace 17 that is a trace of the inert gas injection hole, a paint injection trace 18 that is a trace of the paint injection hole, and a trace of a thermoplastic resin injection hole. The resin injection trace 19 is as follows. The second tab 16 has an air discharge trace 20 which is a trace of the air discharge hole on the surface thereof.

Next, the mold for in-mold coating molding will be described.
As shown in FIGS. 2 and 3, the in-mold coating mold 30 includes a first mold 31, a base mold 32 and a coating film mold 33 which are second molds. Of these, the first cavity 31 and the base material molding die 32 are combined and clamped to form a first cavity 34 for molding the base material 12a in the mold 30 for in-mold coating molding. ing. In addition, in the state where the base material 12a is held on the cavity surface 31a of the first mold 31, the first mold 31 and the coating film forming mold 33 are combined and clamped to mold in-mold coating molding. A second cavity 35 for forming the coating film 13 is formed inside the mold 30.

  The base material mold 32 has a sprue 36 communicating with the first cavity 34. The end of the sprue 36 is opened at the base material cavity surface 32 a of the base material forming mold 32, and the end becomes the resin injection hole 37. The first cavity 34 is filled with the thermoplastic resin forming the base material 12 a from the sprue 36 through the resin injection hole 37. Further, the resin injection trace 19 of the first tab 14 is formed at a position corresponding to the resin injection hole 37.

  The coating film mold 33 has a gas injection path 38, an air discharge path 39 and a paint injection path 40 communicating with the second cavity 35. The gas injection path 38, the air discharge path 39, and the paint injection path 40 are each opened at the coating film cavity surface 33 a of the coating film forming die 33, and the gas injection hole 41, the air discharge hole 42, and the paint An injection hole 43 is formed. The paint injection hole 43 is disposed between the gas injection hole 41 and the air discharge hole 42. A heat insulating material 40 a is provided around the paint injection path 40 to suppress the hardening of the paint in the paint injection path 40.

  As shown in FIGS. 3 and 4, the gas injection hole 41 and the paint injection hole 43 are disposed at positions corresponding to the first tabs 14 of the base material 12a, and the paint injection hole 43 is provided. It is arranged closer to the air discharge hole 42 than the gas injection hole 41. The inner side surface 41 a of the gas injection hole 41 is formed in a tapered shape that expands toward the opening side (second cavity 35 side) of the gas injection hole 41. Then, the inert gas is injected into the second cavity 35 from the gas injection path 38 through the gas injection hole 41, and the paint is injected from the paint injection path 40 in the presence of the inert gas. The paint is filled through the holes 43.

  The gas injection hole 41 is configured to be opened and closed by a valve 44. The valve 44 includes a truncated cone-shaped umbrella portion 44a having a shape corresponding to the gas injection hole 41, and a valve shaft 44b. The valve shaft 44b is supported by a valve guide 38a provided in the gas injection path 38 so as to be capable of reciprocating in the axial direction. An urging member 44c such as a compression spring or a coil spring is provided on the peripheral surface of the valve shaft 44b in the valve guide 38a. The urging member 44 c urges the valve 44 in a direction in which the umbrella portion 44 a is drawn into the gas injection hole 41.

  When the inert gas is injected into the second cavity 35, the valve 44 moves toward the second cavity 35 against the urging force of the urging member 44c due to the pressure from the inert gas, and the umbrella portion 44a is moved. The gas injection hole 41 is opened by projecting into the second cavity 35. On the other hand, when filling the second cavity 35 with the paint, the valve 44 closes the gas injection hole 41 by the urging force of the urging member 44c. At this time, the valve 44 seals the gas injection hole 41 by pressing the peripheral surface of the umbrella part 44 a against the inner side surface 41 a of the gas injection hole 41 by the pressure from the paint applied to the bottom surface of the umbrella part 44 a.

  As shown in FIG. 5, the air discharge hole 42 is disposed at a position corresponding to the second tab 16 of the substrate 12a. Then, the air inside the second cavity 35 is exhausted from the air exhaust path 39 to the outside through the air exhaust hole 42. The first mold 31 is provided with a pressing member 45 so as to be at a position opposite to the air discharge hole 42. The pressing member 45 includes a cylinder portion 46a and a pressing pin 46b attached to the tip of the cylinder portion 46a. The pressing pin 46b is configured to protrude from the cavity surface 31a of the first mold 31 by the operation of the cylinder portion 46a. Then, the pressing pin 46b protrudes from the cavity surface 31a, and the second tab 16 is pushed up and pressed toward the coating film forming die 33 so that the air discharge hole 42 is closed with the second tab 16. It is configured. Further, the coating gas cavity surface 33a closer to the paint injection hole 43 than the air discharge hole 42 is compressed with the inert gas that is compressed when the paint is filled with the air discharge hole 42 closed. A relief portion 47 for escaping the pressure is recessed.

Next, an in-mold coating molding method for the garnish 11 using the in-mold coating molding die 30 will be described.
The in-mold coating molding method in this embodiment includes a base material molding process, a mold exchanging process, and a coating film molding process. The base material forming step is a step of forming the base material 12 a by the first cavity 34 formed from the first mold 31 and the base material forming mold 32. The mold exchanging process is a process of exchanging the second mold from the base material mold 32 to the coating film mold 33 with respect to the first mold 31. The coating film forming step is a step of forming the coating film 13 on the surface of the substrate 12 a by the second cavity 35 formed from the first mold 31 and the coating film forming mold 33.

  As shown in FIGS. 2 and 6, in the base material forming step, first the first cavity 31 is formed by first clamping the first die 31 and the base material forming die 32 (step S100). Next, after the resin melted by heating from the injection gate (not shown) through the sprue 36 is filled into the first cavity 34, the resin is solidified to form the base material 12a (S101). Next, the first mold 31 and the base material mold 32 are opened (S102). In the mold exchange step, the mold is exchanged from the base material mold 32 to the coating film mold 33 while the base 12a is held on the first mold 31 (S103).

  As shown in FIGS. 3 and 6, in the coating film forming step, the first cavity 31 is first clamped to form the second cavity 35 (S104). In S104, mold clamping is performed such that the side edge of the base material 12a is sandwiched between the first mold 31 and the coating film mold 33. For this reason, the leakage of the paint from the inside of the second cavity 35 to, for example, a division part (parting line) between the first mold 31 and the coating film forming mold 33 is suppressed.

  Next, a press-fitting step of press-fitting an inert gas from the gas injection hole 41 into the second cavity 35 with the air discharge hole 42 opened is performed (S105). Accompanying the press-fitting of the inert gas in the press-fitting step, the air in the second cavity 35 is pushed into the air discharge hole 42, and the exhaust step in which the air is pushed out from the air discharge hole 42 is performed (S106). Subsequent to this exhausting step, as shown in FIGS. 5 and 6, a pressing pin 46b is projected to press the second tab 16, and a closing step of closing the air discharge hole 42 by the second tab 16 is performed ( S107). At this time, the timing for projecting the pressing pin 46b is when the inert gas is discharged from the air discharge path 39 instead of air.

  After the closing step of S107, as shown in FIGS. 4 and 6, a filling step of filling the second cavity 35 with a paint is performed (S108). At the start of this filling stage, the space from the paint injection hole 43 to the air discharge path 39 in the second cavity 35 is almost completely replaced by air to an inert gas. That is, the inert gas flows in one direction from the gas injection hole 41 to the air discharge hole 42 in the press-fitting stage of S105, and the air between the gas injection hole 41 and the air discharge hole 42 is inactive in the exhaust stage of S106. It is almost completely pushed out by the active gas. In addition, since the first mold 31 and the coating film mold 33 are already clamped at the stage of S104, and the air discharge hole 42 is closed at the closing stage of S107, it is almost impossible for air to enter again from the outside. No. Since the coating material injection hole 43 is disposed between the gas injection hole 41 and the air discharge hole 42, the coating material flows in the second cavity 35, which is almost completely replaced by the inert gas, The second cavity 35 is filled. The inert gas in the second cavity 35 is pushed in the direction of the air discharge hole 42 by being filled with the paint, and is retracted so as to enter the escape portion 47.

  Subsequently, after the filling step of S108, the coating material filled in the second cavity 35 is heated and cured to form a coating film for forming the coating film 13 on the surface of the substrate 12a (S109). At this time, the air discharge hole 42 is closed at the closing stage of S107, and the paint does not enter the air discharge path 39. Then, the first mold 31 and the base material mold 32 are opened (S110), and the garnish 11 having the first tab 14 and the second tab 16 is removed. Then, the surplus part (the 1st tab 14 and the 2nd tab 16) is cut off, and the garnish 11 is obtained.

The effects exhibited by the above embodiment will be described below.
According to the in-mold coating molding method of the embodiment, when the base end side of the base material 12a is the upstream side and the front end side is the downstream side in the flow direction of the paint in the second cavity 35, the inert gas is The gas injection hole 41 for injecting is disposed upstream of the paint injection hole 43 for injecting the paint. For this reason, a space between the paint injection hole 43 and the air discharge hole 42 in the second cavity 35 is obtained by press-fitting an inert gas from the gas injection hole 41 and discharging the inert gas from the air discharge hole 42. Can be replaced almost completely from air to an inert gas. Therefore, air can be prevented from remaining in the second cavity 35 in which the paint flows, and molding defects of the coating film 13 due to the air remaining can be suppressed.

  In addition, the side edge of the base material 12a is sandwiched between the first mold 31 and the coating film forming mold 33 as described above by exchanging the mold from the base material forming mold 32 to the coating film forming mold 33. Thus, the mold can be clamped to prevent the paint from leaking out.

  In addition, after the exhausting step, the closing step is performed before the filling step, and the air discharge hole 42 is closed, so that the paint enters the air discharge hole 42 and hardens. It is possible to reduce clogging.

  In addition, in the in-mold coating mold 30, the gas injection hole 41, the paint injection hole 43, and the air discharge hole 42 are disposed in order from the upstream side in the second cavity 35, thereby providing the paint injection hole 43. To the air exhaust hole 42, the air in the second cavity 35 can be almost completely replaced with an inert gas. Therefore, air can be prevented from remaining in the second cavity 35 in which the paint flows, and molding defects of the coating film 13 due to the air remaining can be suppressed. Further, since the air in the second cavity 35 is pushed out by injecting an inert gas, it is not necessary to provide a device such as a compressor, and the in-mold coating mold 30 does not become large. It is possible to suppress the remaining of air with a simple configuration.

  In addition, a configuration in which one second mold can be slid in the mold opening / closing direction with respect to the conventional first mold by exchanging the substrate mold 32 and the coating film mold 33. It is difficult to form a gap based on the above, and leakage of the paint from the second cavity 35 to the outside can be suppressed. When the mold is exchanged, the substrate cavity surface 32a of the substrate mold 32 and the coating film cavity surface 33a of the coating film mold 33 can have different shapes. In this case, it is difficult to change the thickness of the coating film on the surface extending in the sliding direction (side surface of the resin molded body) with a conventional mold that slides the second mold in the mold opening / closing direction. With the mold for in-mold coating molding of the embodiment, the thickness of the coating film can be easily changed on the side surface of the resin molded body.

  In addition, since the pressing member 45 is provided and the air discharge hole 42 is closed by the second tab 16, the structure is simpler than that of a mold in which a slide core or the like is provided to close the air discharge hole. . Furthermore, when the air discharge hole is closed with a metal object such as a slide core, it is difficult to seal the gap between the metals. Since the second tab 16 pressed by the discharge hole 42 is slightly deformed and closes the air discharge hole 42, the inflow of the paint into the air discharge hole 42 can be reliably prevented.

  In addition, the inner side surface 41a of the gas injection hole 41 has a tapered shape that expands toward the opening side. In addition, the gas injection hole 41 is provided with a valve 44 that can open and close the gas injection hole 41. The valve 44 includes a truncated cone-shaped umbrella portion 44 a having a shape corresponding to the gas injection hole 41. When the paint is filled, the peripheral surface of the umbrella portion 44a is pressed against the inner side surface 41a by the pressure from the paint applied to the bottom surface of the umbrella portion 44a. At this time, since the pressure from the paint applied to the bottom surface of the umbrella portion 44a is higher than the pressure at which the circumferential surface of the umbrella portion 44a is pressed against the inner side surface 41a, the circumferential surface of the umbrella portion 44a and the inner surface The space between the side surface 41a is sealed. Therefore, the inflow of the paint into the gas injection hole 41 can be suppressed, and clogging of the gas injection hole 41 with the paint can be reduced.

(Example of change)
In addition, this embodiment can also be changed and embodied as follows.
The inner side surface 41a of the gas injection hole 41 is not necessarily tapered, and may be, for example, a polygonal shape such as a triangular shape or a quadrangular shape in addition to a circular cross-sectional shape or an elliptical shape.

  In addition, the valve 44 that configures the gas injection hole 41 to be openable and closable may be omitted. In this case, since the surface pressure applied to the inner surface 41a of the gas injection hole 41 is higher than the pressure at which the paint tries to enter the gas injection hole 41, the inflow of the paint into the gas injection hole 41 is suppressed. And clogging of the gas injection hole 41 due to the paint can be reduced.

  If the gas injection hole 41 can be configured to be freely opened and closed by the valve 44, the valve 44 can be reciprocated by a cylinder such as a hydraulic cylinder, a pneumatic cylinder, or a hydraulic cylinder instead of the biasing member 44c. Good.

  The valve guide 38a is not limited to being provided in the gas injection path 38. For example, the valve guide 38a may be provided immediately above the valve 44, and the gas injection path 38 may be provided so as to avoid the valve guide 38a.

-The pressing member 45 may be omitted. Alternatively, the air discharge hole 42 may be closed by inserting the pressing pin 46 b of the pressing member 45 into the air discharge hole 42.
In the in-mold coating molding method of the present embodiment, one second mold can be slid in the mold opening / closing direction with respect to the first mold without replacing the substrate molding mold 32 and the coating film molding mold 33. The present invention can also be applied to a mold for in-mold coating molding having the structure described above. In this case, a gas injection hole for injecting an inert gas into the second mold may be provided upstream of the paint injection hole.

For example, a compressor may be connected to the air discharge path 39 so that the air is sucked while the air in the second cavity 35 is pushed out with an inert gas.
The filling stage of S108 is not limited to being performed after the closing stage of S107 is completed, but is performed from the end timing of the exhausting stage of S106, and the filling stage of S108 and the closing stage of S107 are completed at the same time. Also good. That is, the injection of paint may be started with the air discharge hole 42 opened, and the air discharge hole 42 may be closed immediately before the injected paint reaches the air discharge hole 42.

  The paint injection hole 43 is not limited to being provided in the coating film forming die 33 and may be provided in the first die 31. In this case, a passage hole through which the paint passes is formed in the substrate 12a. When comprised in this way, since the 1st type | mold 31 becomes low temperature compared with the coating-film shaping | molding die 33, hardening of the coating material in the coating material injection path 40 can be suppressed.

  The resin molded product is not limited to the garnish 11 shown in the embodiment, and has a base material and a coating film applied to the surface thereof, such as a door molding, a bumper, a vehicle interior switch, an audio cover, etc. Any may be sufficient.

-At the time of mold clamping or mold opening, either the first mold or the second mold may be moved.
Further, the technical idea that can be grasped from the embodiment will be described below.
A base material molded using a mold for in-mold coating molding comprising a first mold and a second mold, and molded in a first cavity formed by the first mold and the second mold; and A resin molded article having a base material, and a coating film formed in a second cavity formed by the first mold and the second mold, wherein the base material is formed from the thermoplastic resin. And the coating film is formed by filling the second cavity with an anaerobic paint in a state where the air in the second cavity is replaced with an inert gas, and the base material or the coating film. The resin molded product has traces relating to the injection of the inert gas, the injection of the paint, and the discharge of the air.

(A) is a perspective view which shows the base end part of the garnish which is a resin molded product, (b) is a perspective view which shows the front-end | tip part of a garnish. Sectional drawing which shows the state which clamped the 1st type | mold and the base-material shaping | molding die. Sectional drawing which shows the state which clamped the 1st type | mold and the coating-film shaping | molding die. Sectional drawing which shows a gas injection hole and a coating material injection hole. Sectional drawing which shows an air discharge hole. The flowchart which shows the in-mold coating molding method.

Explanation of symbols

  12a ... base material, 13 ... coating film, 30 ... mold for in-mold coating molding, 31 ... first mold, 31a ... cavity surface, 32 ... base material molding die, 33 ... coating film molding die, 34 ... first cavity 35 ... 2nd cavity, 41 ... Gas injection hole, 41a ... Inner side surface, 42 ... Air discharge hole, 43 ... Paint injection hole, 45 ... Pressing member.

Claims (7)

An in-mold coating molding method for molding a resin molded product having a coating film on the surface of a base material using an in-mold coating molding die including a first mold and a second mold,
A base material forming step of forming the base material in a first cavity formed by the first mold and the second mold, and a second cavity formed by the base material, the first mold, and the second mold. A coating film forming step for forming the coating film from an anaerobic paint within,
The coating film forming step includes a press-fitting step of injecting an inert gas into the second cavity from a gas injection hole provided in the second mold, and a second step from the air discharge hole provided in the second mold. An exhaust stage for exhausting the air in the cavity by press-fitting the inert gas, and a paint injection provided in the second mold or the first mold so as to be positioned between the gas injection hole and the air discharge hole And a filling step of filling the second cavity with the paint in the presence of the inert gas from a hole. The second mold includes a base material mold that forms the first cavity together with the first mold, and a coating film mold that forms the second cavity together with the first mold. 2. The in-mold coating molding according to claim 1, further comprising a mold exchanging step of exchanging the base mold from the base material mold to the coating film mold for the first mold. Mold. The coating film forming step includes a closing step of closing the air discharge hole by the base material after the exhausting step and before the filling step or during the filling step. The in-mold coating molding method according to claim 1 or 2. A mold for in-mold coating molding that molds a resin molded product having a coating film on the surface of a substrate,
A first mold and a second mold are provided, and the base is formed by a first cavity formed by the first mold and the second mold, and is formed by the first mold, the second mold, and the base. The coating is formed by filling anaerobic paint from the paint injection hole provided in the second mold or the first mold into the second cavity to be cured, and
In the second mold, a gas injection hole for injecting an inert gas into the second cavity and an air discharge hole for discharging the air in the second cavity are opened at the cavity surface of the second mold. And the paint injection hole is disposed between the gas injection hole and the air discharge hole. The second mold includes a base mold and a coating mold, a first cavity is formed by the first mold and the base mold, and a second is formed by the first mold and the coating mold. 5. The mold for in-mold coating molding according to claim 4, wherein a cavity is formed. The first mold is provided with a pressing member that presses the base member toward the air discharge hole so as to be opposed to the air discharge hole so as to protrude from the cavity surface of the first mold. 6. The mold for in-mold coating molding according to claim 4 or 5, wherein: The mold for in-mold coating molding according to any one of claims 4 to 6, wherein the gas injection hole is formed in a tapered shape whose inner side surface expands toward the opening side. .

Images