JP4445747B2 - Resin molded product, molding method thereof, and mold for in-mold coating molding - Google Patents

Description

  The present invention relates to a resin molded product having a coating film on the surface of a base material such as a door pillar garnish, a door molding, a bumper and other vehicle exterior materials, a vehicle interior switch, an audio cover, etc., a molding method thereof, and an in-mold coating thereof. The present invention relates to a molding die.

Conventionally, the resin molded product as described above is molded by an in-mold coating method, which is one of injection molding methods, using a mold for in-mold coating molding (see, for example, Patent Documents 1 and 2). That is, the in-mold coating mold includes a fixed mold and a movable mold, and is configured such that a primary cavity is formed inside the fixed mold and the movable mold by clamping the mold. The base material constituting the resin molded product is molded by filling the primary cavity with a synthetic resin and solidifying the synthetic resin. After molding the base material, the secondary cavity is placed inside the mold for in-mold coating molding by sliding the movable mold with respect to the fixed mold while the base material is held on the fixed mold. Is formed. The coating film constituting the resin molded product is molded by injecting a coating material into the secondary cavity, clamping the fixed mold and the movable mold, and then curing the coating material.
JP-A-6-79752 JP 7-290504 A

  By the way, in the above-mentioned conventional mold for in-mold coating molding, the coating material injection path for injecting the coating material is provided so as to open to the surface side of the base material, that is, the side where the coating film is molded to the base material. Yes. On the other hand, the coating material is mainly composed of a thermosetting resin. In order to cure the coating material, a portion of the in-mold coating mold that directly contacts the coating material, that is, a base is used. It is necessary to heat the part which becomes the surface side of the material. However, when the coating film and the coating material injection path are arranged on the same surface side with respect to the base material, even the coating material filled in the coating material injection path may be cured by heating. However, there is a problem that the paint injection path is clogged with the hardened paint, and molding failure of the coating film is likely 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 a resin molded product capable of suppressing molding defects of a coating film, a molding method thereof, and a mold for in-mold coating molding thereof.

In order to achieve the above object, an in-mold coating mold according to claim 1 is an in-mold coating molding mold for molding a resin molded product having a coating film on the surface of a substrate. A fixed mold, a substrate mold, and a coating film mold, a primary cavity formed by the fixed mold and the substrate mold is filled with a thermoplastic resin, and the thermoplastic resin is cooled and solidified. the shaped said substrate by said substrate and said by the substrate to the mold clamping and the coating film forming die and the stationary die while being held in the cavity surface of the fixed mold coating molding A coating made of a thermosetting resin is filled in a secondary cavity formed between molds, and the coating is formed by heating and curing the coating, and the coating is injected. The mold in which the paint injection path is on the back side of the base material Provided in the fixed mold so as to open at the surface, and at the time of molding the coating film, an introduction hole is formed so as to penetrate the substrate at a position corresponding to the paint injection path when molding the substrate. The gist is that the paint is filled into the secondary cavity from the paint injection path through the introduction hole.

  In the invention having the above configuration, since the paint for forming the coating film is made of a thermosetting resin, it is necessary to heat and cure the paint at the time of forming the coating film. In the mold for in-mold coating molding of the present invention, the coating film is molded on the surface of the base material in the secondary cavity, and the paint injection path for injecting the paint is disposed on the back side of the base material. ing. Further, at the time of molding the base material, the introduction hole is formed so as to penetrate the base material at a position corresponding to the paint injection path of the base material, and the paint injected from the back side of the base material is , The surface of the base material is filled through the introduction hole. That is, the secondary cavity for forming the coating film and the paint injection path for injecting the paint are arranged so as to be opposite to each other with the base material interposed therebetween. Therefore, even when heat is applied to cure the paint, the influence of the heat is not easily transmitted to the inside of the paint injection path, and it is possible to suppress the hardening of the paint in the paint injection path. As a result, it is possible to suppress coating film formation defects that occur due to clogging of the paint injection path.

In addition, a primary cavity or a secondary cavity can be formed by using two different molds, a base mold and a coating mold, as the movable mold, and exchanging them while moving the fixed mold. It is configured. In the conventional mold for in-mold coating molding, the secondary cavity is formed by sliding the movable mold with respect to the fixed mold. That is, the secondary cavity is formed by expanding the primary cavity in the direction in which the movable mold is slid and moved in the conventional mold for in-mold coating molding, and is formed by the cavity surface of the movable mold. The surface shape of the material is the same as the surface shape of the coating film. On the other hand, in the present invention, the movable mold is exchanged from the base mold to the coating film mold with respect to the fixed mold when the secondary cavity is formed. As a result, the surface shape of the substrate formed by the cavity surface of the substrate mold and the surface shape of the coating film formed by the cavity surface of the coating film mold can be made different from each other.

According to a second aspect of the invention of the mold for in-mold coating molding according to the first aspect of the present invention, in the first aspect of the invention, there is provided a closing means for closing the paint injection path from the inside when the base material is molded. Is the gist.

  In the invention having the above-described configuration, the paint injection path can be closed by the closing means when the base material is molded. As a result, it is possible to suppress the clogging of the paint injection path by the thermoplastic resin entering and solidifying the paint injection path.

According to a third aspect of the invention of the mold for in-mold coating molding according to the first or second aspect , the paint injection nozzle for filling the paint in the paint injection path is provided, and the paint injection nozzle is provided. The coating material injection nozzle is provided with a cooling means for cooling the coating material filled therein.

  In the invention with the above configuration, the heat transfer to the paint in the paint injection nozzle can be suitably blocked by forming the paint injection nozzle with a heat insulating material and further providing a cooling means. As a result, curing of the paint in the paint injection nozzle can be suitably suppressed.

Invention-mold coating molding die according to claim 4 is the invention according to claim 3, wherein the coating material injection nozzle is disposed so that its tip is exposed to the primary cavity In addition, the gist is that a groove or protrusion is provided on the tip surface of the coating material injection nozzle, and a thermoplastic resin is filled in or around the groove when the base material is molded.

  In the invention of the above configuration, when the thermoplastic resin filled in the groove portion or around the protrusion is solidified when the base material is molded, the solidified thermoplastic resin causes the tip of the paint injection nozzle and the base material to be solidified. It becomes possible to seal the gap formed between them. As a result, leaching of the paint from the gap can be suppressed.

Invention-mold coating molding die according to claim 5, collision in the invention of claim 3 or claim 4, a core member for forming the introduction hole on the cavity surface of the movable mold The gist of the invention is to bring the tip of the core member into contact with the tip of the paint injection nozzle when the substrate is formed.

  In the invention having the above-described configuration, the coating material injection path can be closed by the core member that forms the introduction hole when the base material is molded. As a result, it is possible to suppress positional deviation between the paint injection path and the introduction hole, and it is possible to suppress clogging due to the thermoplastic resin entering and solidifying the paint injection path.

According to a sixth aspect of the present invention, in the third aspect of the present invention, the paint injection nozzle is disposed such that a tip end portion thereof is positioned inside the fixed mold. In addition, the gist of the invention is that an O-ring that seals between the tip portion and the fixed mold is fitted to the tip portion of the paint injection nozzle.

  In the invention having the above-described configuration, the paint injection nozzle can be disposed in the inner part of the fixed mold that is not easily affected by heat, and the paint injection is performed by an O-ring fitted to the tip of the paint injection nozzle. It is possible to seal a gap formed between the tip of the nozzle and the fixed mold. As a result, the curing of the paint due to the influence of heat and the leaching of the paint from the gap can be suppressed.

According to a seventh aspect of the present invention, there is provided the mold for in-mold coating molding according to the third or sixth aspect, wherein a core member for forming the introduction hole is formed on the cavity surface of the movable mold. The gist is that the tip of the core member is inserted into the paint injection path in a state in which the core member emerges from the movable cavity surface while being provided so as to be able to protrude from the cavity surface.

  In the invention having the above-described configuration, the coating material injection path can be closed by the core member that forms the introduction hole when the base material is molded. As a result, it is possible to suppress positional deviation between the paint injection path and the introduction hole, and it is possible to suppress clogging due to the thermoplastic resin entering and solidifying the paint injection path.

The invention for an in-mold coating mold according to claim 8 is the invention according to claim 6 or 7 , wherein a groove or a protrusion is provided on the periphery of the paint injection path on the cavity surface of the fixed mold. The gist of the invention is that the thermoplastic resin is filled in the groove or around the protrusion when the substrate is molded.

  In the invention of the above configuration, the injection of paint that opens in the fixed cavity surface with the solidified thermoplastic resin by solidifying the thermoplastic resin filled in the groove portion or around the protrusion during molding of the base material It is possible to seal a gap formed between the path and the base material. As a result, leaching of the paint from the gap can be suppressed.

The invention of the resin molded product according to claim 9 is molded using an in-mold coating molding die comprising a stationary die, a base material molding die, and a coating film molding die, and the stationary die and the base material molding die. A base material molded in a primary cavity formed by the method , and clamping the fixed mold and the coating film mold in a state where the base material is held on the cavity surface of the fixed mold. A resin molded article having a coating film formed in a secondary cavity formed between a material and the coating film mold , wherein the base material is molded from the thermoplastic resin, The coating film is formed from a paint made of a thermosetting resin, and an introduction hole penetrating the base material is formed in the base material, and the paint is passed through the introduction hole on the back side of the base material. The main point is that it was injected into the surface.

  In the invention having the above configuration, since the paint for forming the coating film is made of a thermosetting resin, it is necessary to heat and cure the paint at the time of forming the coating film. In the present invention, the secondary cavity for forming the coating film and the coating material injection path for injecting the coating material are disposed so as to be opposite to each other with the base material interposed therebetween. Therefore, even if heat is applied to cure the paint, it is difficult for the influence of the heat to be transmitted to the paint before filling the secondary cavity, and it is possible to suppress the paint from hardening before filling. As a result, molding defects of the coating film can be suppressed.

Invention of the molding method of the resin molded article according to claim 1 0, using a mold coated mold and a fixed mold and a substrate mold and coating the mold, the coating film on the surface of the substrate having a molding method for molding the resin molded article, after filling the thermoplastic resin in advance molding the substrate to the fixed mold and in the primary cavity formed by the base mold, the substrate heat but the second cavity formed between the substrate and the coating film forming die by clamping and the coating film forming die and the stationary die while being held in the cavity surface of the fixed mold A coating made of a curable resin is injected to form the coating film, and when the base material is molded, an introduction hole is formed in the base material so as to penetrate the base material. Injecting the paint from the back side of the base material to the surface through the hole To do.

  In the invention having the above configuration, since the paint for forming the coating film is made of a thermosetting resin, it is necessary to heat and cure the paint at the time of forming the coating film. In the present invention, the secondary cavity for forming the coating film and the coating material injection path for injecting the coating material are disposed so as to be opposite to each other with the base material interposed therebetween. Therefore, even if heat is applied to cure the paint, it is difficult for the influence of the heat to be transmitted to the paint before filling the secondary cavity, and it is possible to suppress the paint from hardening before filling. As a result, molding defects of the coating film can be suppressed.

  As described above in detail, according to the present invention, it is possible to provide a resin molded product capable of suppressing molding defects of a coating film, a molding method thereof, and a mold for in-mold coating molding thereof.

Hereinafter, an embodiment in which the resin molded product of the present invention is embodied in a door pillar garnish will be described with reference to the drawings.
As shown in FIG. 1, the door pillar garnish 21 is attached to the door pillar portion 12 of the door 11 of the automobile so as to cover the entire outside of the vehicle. That is, the door pillar garnish 21 has a shape corresponding to the door pillar portion 12 and is formed in a thin plate shape along the outer surface of the door pillar portion 12.

  As shown in FIGS. 2 (a) and 2 (b), the resin molded product has the door pillar garnish 21 which is a molded product main body portion, and a tab portion 22 which is a surplus portion formed at the end portion thereof. Yes. That is, the door pillar garnish 21 is formed by cutting out the tab portion 22 from the resin molded product. The resin molded product may have a surplus portion such as a runner portion in addition to the tab portion 22. Therefore, in this embodiment, a resin molded product is a product having a molded product main body portion and a surplus portion.

  The resin molded product has a base material 23 made of a thermoplastic resin and a coating film 24 made of a paint. This paint is made of a thermosetting resin and contains a pigment. In addition, when transparency is required for the coating film, a paint containing no pigment is used. The coating film 24 is formed so as to cover the surface 25 of the base material 23 with a substantially uniform thickness. Here, the surface 25 of the base material 23 indicates a surface that is on the vehicle exterior side when the door pillar garnish 21 is attached to the door pillar portion 12. Further, the coating film 24 is not provided on the back surface 26 of the base material 23 opposite to the front surface 25, and the background of the base material 23 is exposed on the back surface 26. The door pillar garnish 21 is designed to improve the design and protect the surface 25 by the coating film 24 provided on the surface 25 of the base material 23.

  On the other hand, in the tab portion 22, a concave portion 27 is formed in the approximate center of the back surface 26. An annular seal portion 27 a is provided inside the recess 27. Further, an introduction hole 28 is formed through the base material 23 in the center of the seal portion 27a. The coating film 24 is formed by being injected from the back surface 26 side of the base material 23 to the front surface 25 so that the coating material penetrates the base material 23 through the introduction hole 28. Further, the opening on the surface 25 side of the introduction hole 28 is closed by a truncated cone-shaped convex portion 29 protruding substantially at the center on the surface 25 of the tab portion 22. The convex portions 29 are formed by curing the paint when the coating film 24 is molded.

  As the paint, one made of a liquid thermosetting composition is used. In general, paints contain volatile components such as organic solvents and water. However, when a volatile component is present inside the sealed mold for in-mold coating molding, defective molding of the coating film may occur. In view of this, a paint made of a liquid thermosetting composition does not contain a predetermined volatile component, that is, a coating that does not contain a volatile component whose boiling point is lower than the set temperature of the mold for in-mold coating molding.

Next, the configuration of an in-mold coating mold for molding the resin molded product will be described.
As shown in FIGS. 3 and 4, the in-mold coating mold includes a fixed mold 41, a base mold 42 as a movable mold, and a coating film mold 43. The fixed die 41 has a fixing cavity surface 44 that has an uneven shape. The fixing cavity surface 44 is formed to have a shape corresponding to the shape of the back surface 26 of the substrate 23. The base material mold 42 has a base material cavity surface 45 having a concave shape. The substrate cavity surface 45 is formed to have a shape corresponding to the shape of the surface 25 of the substrate 23. The coating film forming die 43 has a coating-cavity surface 46 having a concave shape. The coating film cavity surface 46 is formed to have a shape corresponding to the shape of the surface of the coating film 24.

  Then, by clamping using the fixed mold 41 and the base material mold 42, a primary cavity 47 having a shape corresponding to the base material 23 is formed between the fixed mold 41 and the base material mold 42. Is formed. The base mold 42 has a sprue 48 that communicates with the primary cavity 47. The primary cavity 47 is configured to be filled with a thermoplastic resin for molding the base material 23 through the sprue 48.

  On the other hand, as indicated by a chain line in FIG. 4, a mold is formed using the fixed mold 41 and the coating film forming mold 43 in a state where the base material 23 is held on the fixing cavity surface 44 of the fixed mold 41. By tightening, a secondary cavity 51 having a shape corresponding to the coating film 24 is formed between the base material 23 and the coating film forming die 43. The fixed mold 41 has a paint injection nozzle 52 for filling the secondary cavity 51 with the paint. The base material mold 42 has a core member 53 at a position corresponding to the paint injection nozzle 52. The core member 53 includes a cylinder portion 54 and a core pin 55 attached to the tip of the cylinder portion 54. The core pin 55 is configured to be able to protrude and retract from the base material cavity surface 45 by the operation of the cylinder portion 54. Then, the core pin 55 is caused to appear from the substrate cavity surface 45, and the thermoplastic resin is filled from the sprue 48 in a state where the tip of the core pin 55 is in contact with the paint injection nozzle 52. The introduction hole 28 is formed in the base material 23.

Here, the configuration of the paint injection nozzle 52 will be described.
As shown in FIG. 5, the paint injection nozzle 52 has a box-like case 61 and a nozzle body 62 housed in the case 61.

  The case 61 is provided to suppress heat transfer from the fixed mold 41 to the nozzle body 62 when the paint is heated and cured. Therefore, the case 61 is formed of a heat insulating material such as ceramics, titanium alloy, stainless steel, engineering plastic or the like. The case 61 includes a first cover 63 that covers the nozzle body 62 from below, and a second cover 64 that covers the nozzle body 62 from above. The first cover 63 and the second cover 64 serve as nozzles. The main body 62 is provided so as to be sandwiched from above and below. A flange 63a protrudes from the upper edge of the first cover 63, and the paint injection nozzle 52 is fixed to the fixed mold 41 with a bolt or the like (not shown) through the flange 63a. Also, as shown in FIGS. 3 and 4, an air layer 64 a composed of a gap is provided between the second cover 64 and the fixed mold 41, and the heat insulation effect is enhanced. The reason why the air layer 64a is provided around the second cover 64 is that, in the paint injection nozzle 52, the portion where the second cover 64 is provided is close to the fixing cavity surface 44 and is easily affected by heat. is there. The case 61 is preferably formed of a heat insulating material having a high heat insulating effect in the order of the second cover 64 and the first cover 63 in consideration of the influence of heat.

  The nozzle body 62 is formed in a cylindrical shape using a heat insulating material in the same manner as the case 61. The nozzle body 62 is disposed such that the tip end portion thereof is exposed into the secondary cavity 51, and is easily affected by the heat. Therefore, the tip of the nozzle body 62 is configured as a heat shield 62a formed from a heat insulating material having a particularly high heat insulating effect.

  Inside the nozzle body 62, a paint injection path 71 for injecting the paint into the secondary cavity 51 is formed in an L shape. One end of the paint injection path 71 reaches the heat shield 62 a and is opened by a fixing cavity surface 44 for molding the back surface 26 of the base material 23, thereby forming a paint injection port 72. The other end of the paint injection path 71 reaches the first cover 63 and is opened through the first cover 63 to form a paint supply port 73. The paint supplied from the paint supply port 73 flows through the paint injection path 71 and is injected from the paint injection port 72. In addition, a groove 74 is formed in an annular shape so as to surround the paint injection port 72 on the inner periphery of the paint injection port 72 on the front end surface of the heat shield 62a. Note that one end portion of the coating material injection path 71 is formed in a tapered shape whose diameter decreases toward the coating material injection port 72.

  A pair of upper and lower annular grooves are recessed in the outer peripheral surface of the nozzle body 62, and cooling chambers 81 are respectively formed inside the annular groove and the second cover 64. The cooling chamber 81 is supplied with coolant such as water and cold air from a coolant supply passage (not shown). A cooling means is constituted by the cooling chamber 81, the refrigerant supply path, and the like. The cooling means is configured to block heat transfer from the case 61 and the like to the paint filling the paint injection path 71 and flowing through the coolant by circulating the refrigerant in the cooling chamber 81. In addition, a pair of upper and lower O-rings 82 are fitted on the outer peripheral surface of the nozzle body 62 with the annular groove inside, and leakage of the refrigerant from the cooling chamber 81 is suppressed.

  A valve pin 91 is inserted into the nozzle body 62 from below. The valve pin 91 is connected to the actuator 92 at the base end, and most of the valve pin 91 is accommodated in the paint injection path 71. The valve pin 91, the actuator 92 and the like constitute a closing means. The closing means advances the valve pin 91 toward the paint injection port 72 by the operation of the actuator 92 and presses the tip peripheral surface of the valve pin 91 against the inner peripheral surface of the paint injection path 71, whereby the paint injection path 71 is closed from the inside. A seal ring 93 is fitted to the base end of the valve pin 91. The seal ring 93 seals between the valve pin 91 and the nozzle main body 62, and suppresses leakage of the paint from between them.

Next, a method for molding a resin molded product using the above-mentioned mold for in-mold coating molding will be described.
The method for molding the resin molded product includes a base material forming step for forming the base material 23 and a coating film forming step for forming the coating film 24 on the surface of the base material 23.

  As shown in FIG. 6, in the base material forming step, first, the fixed die 41 and the base material forming die 42 are clamped, and a primary cavity 47 is formed between them. At this time, in the paint injection nozzle 52, the paint injection port 72 of the paint injection path 71 is closed by the valve pin 91. In the base material mold 42, the core pin 55 is protruded from the base material cavity surface 45, and the tip thereof is brought into pressure contact with the tip of the coating material injection nozzle 52. Thereafter, the thermoplastic resin is cooled and solidified in the primary cavity 47 while the primary cavity 47 is filled with the thermoplastic resin from the sprue 48 of the base material mold 42, thereby forming the base material 23. The

  In the base material molding step, the introduction hole 28 is formed in the base material 23 by the core pin 55. At the periphery of the introduction hole 28, the thermoplastic resin is cooled and solidified so as to cover the front end portion of the paint injection nozzle 52, so that the portion that becomes the tab portion 22 on the back surface 26 of the base material 23 has the concave portion. 27 is formed. When the concave portion 27 is formed, the thermoplastic resin is also filled in the groove portion 74 provided on the tip surface of the paint injection nozzle 52. By sealing and solidifying the thermoplastic resin filled in the groove 74, a seal portion 27a is formed in the recess 27. When the seal portion 27a is formed, the thermoplastic resin to be cooled and solidified contracts so as to tighten the tip of the paint injection nozzle 52. As a result, the seal portion 27 a has its peripheral surface in close contact with the inner peripheral surface of the groove portion 74, and seals a gap formed between the tip of the paint injection nozzle 52 and the back surface 26 of the base material 23. It will be a thing. In addition, the seal portion 27 a suppresses the separation of the base material 23 from the fixed mold 41 by tightening the tip of the coating material injection nozzle 52.

  After the base material 23 is formed, the fixed mold 41 and the base material forming mold 42 are opened. This mold opening is performed by separating the fixed mold 41 from the base material mold 42. In addition, when the mold is opened, the base material 23 is held on the fixing cavity surface 44 with the back surface 26 in contact with the fixing cavity surface 44. Separated from 42. This completes the base material forming step.

  As shown in FIG. 7, in the coating film forming step, first, the movable mold is exchanged and moved from the substrate forming mold 42 to the coating film forming mold 43, and then the fixed mold 41 is moved with respect to the coating film forming mold 43. The fixed die 41 and the coating film forming die 43 are clamped together. At the time of clamping, since the base material 23 is held on the fixing cavity surface 44 of the fixed die 41, the secondary cavity 51 is interposed between the surface 25 of the base material 23 and the coating film forming die 43. Is formed. Thereafter, in the paint injection nozzle 52, the valve pin 91 is moved back into the nozzle body 62, whereby the paint injection port 72 of the paint injection path 71 is opened. Then, the paint is filled into the secondary cavity 51.

  The paint is filled into the secondary cavity 51 through the following route. That is, the paint is first filled in the paint injection path 71, flows through the paint injection path 71, and reaches the paint injection port 72. The paint reaching the paint injection port 72 is injected from the paint injection port 72 and passes through the introduction hole 28 of the base material 23, so that the back surface 26 side of the base material 23 forms the base material 23. It is injected toward the secondary cavity 51 formed on the surface 25.

  When the paint is filled, the tip of the paint injection nozzle 52 and the back surface 26 of the base material 23 are sealed by the seal portion 27a, so that the paint leaks or leaches out between them. The paint is preferably flowed into the introduction hole 28. Further, when the coating material is filled, the concave portion 27 of the base material 23 is separated from the tip end surface of the coating material injection nozzle 52 by the pressure applied at the time of filling, and the seal by the seal portion 27a may be loosened. However, the seal portion 27a suppresses the lifting of the concave portion 27 by tightening the tip of the coating material injection nozzle 52. As a result, the seal by the seal portion 27a is preferably maintained. A depression is formed in the coating film cavity surface 46 of the coating film forming die 43 at a position facing the coating material injection port 72. This depression stores sludge composed of hardened paint, dust and the like. By storing the sludge in the recess in this way, the paint is filled in the secondary cavity 51 in a state where the injection pressure is stable. When the coating material filled in the depression is cured, the convex portion 29 is formed on the surface 25 of the tab portion 22.

  And the coating film 24 is shape | molded on the surface 25 of the base material 23 by filling this in the secondary cavity 51, and heating this reaction material and carrying out reaction hardening. Curing of the paint is performed by heating the coating film mold 43. That is, when both the fixed mold 41 and the coating film mold 43 are heated, the base material 23 is made of a thermoplastic resin, so that the base material 23 heated through the fixed mold 41 is softened, By remelting, there is a possibility that molding defects may occur. For this reason, the coating film forming die 43 is maintained at a temperature that promotes reaction hardening of the paint by being heated, while the fixed die 41 is left on the substrate 23 by being left standing, cooled, or the like. The temperature is maintained at a level that does not cause molding defects. Accordingly, since the temperature of the fixed mold 41 is lower than the temperature of the coating film forming mold 43, the reaction curing of the paint is not accelerated at the temperature of the fixed mold 41, and the paint injection nozzle 52 provided in the fixed mold 41. , The curing of the paint flowing through the paint injection path 71 is suppressed.

  Thereafter, the fixed mold 41 and the coating film mold 43 are opened, and the resin molded product is separated from the fixed mold 41 and collected. This finishes the coating film forming process. The recovered resin molded product is shipped as a door pillar garnish 21 with the tab portion 22 cut off.

The effects exhibited by the above embodiment will be described below.
The resin molded product of the embodiment has a coating film 24 on the surface 25 of the base material 23, the base material 23 is made of a thermoplastic resin, and the coating film 24 is a liquid thermosetting composition. It consists of a reactive curable coating containing. This resin molded product is molded using a mold for in-mold coating molding. The in-mold coating molding die is configured such that a secondary cavity 51 for molding the coating film 24 and a paint injection nozzle 52 for injecting paint are disposed on opposite sides of the base material 23. ing. In addition, the base material 23 is formed with an introduction hole 28 that penetrates the base material 23 at the time of molding. By forming the introduction hole 28, even if the paint injection nozzle 52 is disposed on the opposite side of the base 23 with respect to the secondary cavity 51, the paint is introduced into the secondary cavity 51 via the introduction hole 28. Can be filled. Since the secondary cavity 51 for forming the coating film 24 and the coating material injection nozzle 52 for injecting the coating material are arranged on opposite sides of the base material 23, it is affected by the heating during the coating film 24 molding. It is possible to prevent the paint in the paint injection nozzle 52 from being cured. Therefore, it is possible to suppress the occurrence of defective molding of the coating film 24 due to clogging of the coating material injection nozzle 52, unstable injection of the coating material, or the like.

  The movable mold is composed of two different base molds 42 and coating film molds 43. When the primary cavity 47 or the secondary cavity 51 is formed, the base mold 42 and the coating film are formed. The mold 43 is exchanged. It is possible to form completely different cavity surfaces in the base material mold 42 and the coating film mold 43. Therefore, the coating film 24 can be formed to have a uniform thickness over the entire surface 25 of the substrate 23, and a part of the coating film 24, particularly, the coating film 24 formed on the side surface of the door pillar garnish 21 becomes thin. The molding defect which arises can be suppressed.

  Further, at the time of molding the base material 23, the paint injection port 72 of the paint injection path 71 is closed from the inside by the valve pin 91. Therefore, it is possible to prevent the thermoplastic resin from entering the paint injection path 71 from the paint injection port 72 and solidifying it, thereby preventing the paint injection port 72 from being clogged, and suppressing molding defects caused by the failure of the paint injection port 72. can do.

  In addition, by providing a cooling chamber 81 inside the coating material injection nozzle 52 and cooling the coating material in the coating material injection path 71 or blocking heat transfer from the outside, curing of the coating material can be suitably suppressed. Forming defects due to clogging of the passage 71 and the like can be suppressed.

  In addition, since most of the paint injection nozzle 52 is formed of a heat insulating material, it is possible to more suitably suppress the hardening of the paint by suitably blocking heat transfer from the outside. It is possible to suppress molding defects caused by 71 clogging and the like.

  In addition, a groove 74 is recessed in the tip surface of the paint injection nozzle 52, and the groove 74 is filled with a thermoplastic resin when the base 23 is molded, so that the paint injection nozzle 52 and the base 23 The gap is configured to be sealed. Accordingly, it is possible to prevent the coating material from leaking from the space between the base material 23 and the coating material injection nozzle 52 and to suppress the molding failure of the coating film 24.

  The core pin 55 that forms the introduction hole 28 is in pressure contact with the tip of the paint injection nozzle 52 when the base material 23 is molded. Therefore, it is possible to block the coating material injection port 72 with the core pin 55 and reliably prevent the thermoplastic resin from entering the coating material injection port 72, and suppress molding defects caused by clogging of the coating material injection path 71 and the like. be able to.

  In addition, by bringing the core pin 55 into contact with the tip of the coating material injection nozzle 52, it is possible to ensure the alignment between the introduction hole 28 and the coating material injection port 72, and the coating film due to these positional shifts. 24 molding defects can be suppressed.

In addition, this embodiment can also be changed and embodied as follows.
As shown in FIG. 8, the paint injection nozzle 52 may be shifted inward of the fixed mold 41 so that the paint injection port 72 of the paint injection nozzle 52 is positioned inside the fixed mold 41. In this case, it is possible to further reduce the influence on the coating material injection nozzle 52 by heating. In such a configuration, the paint injection path includes a first paint injection path 71 a provided in the paint injection nozzle 52 and a second paint injection path 71 b provided in the fixed mold 41. . The second coating material injection path 71 b is formed so as to communicate with the first coating material injection path 71 a and to have one end opened at the fixing cavity surface 44 of the fixed mold 41. Further, it is preferable that an O-ring 82 is fitted inside the groove 74 to prevent the paint from leaking into the fixed mold 41. In addition, it is preferable that the tip of the core pin 55 is inserted into the second paint injection path 71b by increasing the amount of movement of the core pin 55, and the paint injection path 71 is closed when the base material 23 is molded.

  As shown in FIG. 9, in the configuration in which the paint injection nozzle 52 is shifted inward of the fixed mold 41, the fixing strip surface 74 at the peripheral edge of the second paint injection path 71 b is formed on the concave strip 74 a or the convex strip 74 b. May be provided. These concave strips 74a or convex strips 74b form a seal portion on the base material 23 of the resin molded body. That is, the thermoplastic resin is cooled and solidified inside the concave stripe 74 a or around the convex stripe 74 b to form a seal portion on the base material 23. The seal portion formed in this manner is contracted by the thermoplastic resin on the inner peripheral surface of the concave line 74a or the surface of the convex line 74b, so that the surface is the inner peripheral surface of the concave line 74a or the surface of the convex line 74b. Close to. Therefore, the seal portion seals between the surface thereof and the inner peripheral surface of the concave stripe 74a or the surface of the convex stripe 74b, that is, between the base material and the peripheral edge of the second paint injection path 71b, thereby preventing the leakage of the paint. While suppressing, the concave line 74a or the convex line 74b is tightened, and this seal is suitably maintained.

  If it is possible to form the introduction hole 28 in the base material 23, it is not always necessary to provide the core pin 55. For example, the tip of the paint injection nozzle 52 is brought into contact with the base material cavity surface 45 of the base material forming mold 42. For example, the introduction hole 28 may be formed.

  In the configuration in which the tip end portion of the paint injection nozzle 52 is exposed into the primary cavity 47, the gap between the paint injection nozzle 52 and the substrate 23 is sealed by fitting an O-ring inside the groove 74. You may comprise as follows.

  In place of the groove 74, a protrusion may be provided around the paint injection port 72 at the tip of the paint injection nozzle 52 so as to surround the paint injection port 72 inside. In this case, the seal portion is formed in an annular groove shape inside the concave portion 27. The seal portion seals between the base material 23 and the tip of the paint injection nozzle 52 by bringing the peripheral surface into close contact with the peripheral surface of the projection due to the shrinkage of the thermoplastic resin. The seal is suitably maintained by tightening.

  The cooling means is not limited to the one shown in the embodiment as long as the paint in the paint injection path 71 can be cooled. For example, the cooling means is configured by conducting a coolant such as cold air to the air layer 64a. May be. Alternatively, the cooling means may be omitted if the influence of heat on the paint in the paint injection path 71 is sufficiently small.

-When the base material 23 is molded, the blocking means may be omitted if the penetration of the thermoplastic resin into the paint injection path 71 can be sufficiently suppressed.
The movable mold may be configured with only one mold, and the movable mold may be configured to slide to the fixed mold to form a secondary cavity.

  -The resin molded product is not limited to the door pillar garnish and tab portion shown in the embodiment, but is applied to the base material and its surface such as a door molding, bumper, vehicle interior switch, audio cover, etc. Any film may be used as long as it has a film.

  -In general molds, with the mold clamping or mold opening as a reference, what is fixed at this time is called the fixed side, and what is moved is called the movable side. On the other hand, in the present specification, regardless of this general designation, on the basis of the formation of the secondary cavity, the fixed base is the one that fixes the base material, and the movable type is the one that is combined with the fixed mold. It is described. Therefore, either the fixed mold or the movable mold may be moved when the mold is clamped or opened.

The side view which shows the state which attached the door pillar garnish. (A) is a perspective view which shows the state which looked at the resin molded product from the surface, (b) is a perspective view which shows the state which looked at the resin molded product from the back surface. Sectional drawing which shows the state which formed the primary cavity. Sectional drawing which shows the state which formed the secondary cavity. Sectional drawing which shows a coating material injection | pouring nozzle. Sectional drawing which shows the state which shape | molds a base material. Sectional drawing which shows the state which shape | molds a coating film. Sectional drawing which shows the coating material injection nozzle of another form. Sectional drawing which shows the coating material injection nozzle of another form.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 21 ... Door pillar garnish as a resin molded product, 23 ... Base material, 24 ... Coating film, 25 ... Surface of base material, 26 ... Back surface of base material, 28 ... Introduction hole, 41 ... Fixed type, 42 ... Constituent type A substrate mold for forming a substrate 43, a coating film mold for forming a movable mold, 44 a cavity surface for fixing which is a cavity surface of a fixed mold, 45 a cavity surface for substrate which is a cavity surface of a movable mold, 47 ... 1 Secondary cavity, 51 ... Secondary cavity, 52 ... Paint injection nozzle, 53 ... Core member, 71 ... Paint injection path, 74 ... Groove, 81 ... Cooling chamber constituting cooling means, 82 ... O-ring, 91 ... Closing means A valve pin constituting the actuator 92... An actuator constituting the closing means.

Claims (10)

A mold for in-mold coating molding that molds a resin molded product having a coating film on the surface of a substrate,
A fixed mold, a base mold, and a coating mold ; a primary cavity formed by the fixed mold and the base mold is filled with a thermoplastic resin, and the thermoplastic resin is cooled and solidified. The base material and the coating film molding die are clamped between the fixed mold and the coating film molding die in a state where the base material is molded by the mold and the base material is held on the cavity surface of the stationary mold. Filled with a paint made of a thermosetting resin in a secondary cavity formed therebetween, and is configured such that the coating film is formed by heat curing the paint,
A paint injection path for injecting the paint is provided in the fixed mold so as to open at the cavity surface on the back side of the base material, and the base material is placed at a position corresponding to the paint injection path when the base material is molded By forming the introduction hole so as to penetrate, the coating material is filled from the coating material injection path into the secondary cavity through the introduction hole when the coating film is formed. Mold for in-mold coating molding. 2. The in- mold coating molding die according to claim 1 , further comprising: a closing unit that closes the coating material injection path from the inside when the base material is molded . 3. The paint injection nozzle for filling the paint is provided in the paint injection path, the paint injection nozzle is formed of a heat insulating material, and the paint injection nozzle is provided with a cooling means for cooling the paint filled therein. mold coating molding die according to claim 1 or claim 2, characterized in that. The coating material injection nozzle is disposed such that a tip portion thereof is exposed into the primary cavity, and a groove portion or a protrusion is provided on a tip surface of the coating material injection nozzle. The mold for in-mold coating molding according to claim 3 , wherein a thermoplastic resin is filled inside or around the protrusion . A core member for forming the introduction hole is projected on the movable cavity surface, and the tip of the core member is brought into contact with the tip of the paint injection nozzle when the base material is molded. The mold for in-mold coating molding according to claim 3 or 4. The coating material injection nozzle is disposed so that a tip portion thereof is positioned inside the fixed mold, and an O-ring that seals between the tip portion and the fixed mold is provided at the tip portion of the coating material injection nozzle. mold coating molding die according to claim 3, characterized in that fitted to. A core member for forming the introduction hole is provided on the movable cavity surface so as to protrude from the cavity surface, and the tip of the core member is in a state where the core member emerges from the movable cavity surface. claim 3 or mold coating molding die according to claim 6, characterized in that it is inserted into the paint injection path. A groove or projection is provided on the periphery of the paint injection path on the cavity surface of the fixed mold, and a thermoplastic resin is filled inside or around the projection when the base material is molded. Item 8. A mold for in-mold coating molding according to item 6 or claim 7. A base molded in a primary cavity formed by an in-mold coating mold comprising a fixed mold, a substrate mold, and a coating film mold, and formed by the fixed mold and the substrate mold A material is formed between the substrate and the coating film mold by clamping the fixed mold and the coating film molding mold with the substrate held on the cavity surface of the fixed mold. A resin molded product having a coating film molded in the secondary cavity,
The base material is formed from the thermoplastic resin, the coating film is formed from a paint made of a thermosetting resin, and an introduction hole penetrating the base material is formed in the base material. A resin molded product, wherein the paint is injected from the back side of the base material to the surface through the introduction hole . A molding method for molding a resin molded product having a coating film on the surface of a substrate using a mold for in-mold coating molding comprising a fixed mold, a substrate molding mold and a coating film molding mold,
  A primary cavity formed by the fixed mold and the base mold is filled with a thermoplastic resin and the base is molded in advance, and then the base is held on the cavity surface of the fixed mold. The paint film made of a thermosetting resin is injected into a secondary cavity formed between the substrate and the paint film mold by clamping the fixed mold and the paint film mold. And forming an introduction hole in the base material so as to penetrate the base material when the base material is molded, and the coating material is passed through the introduction hole when forming the coating film on the back side of the base material. A method for molding a resin molded product, characterized by being injected into the surface from the surface.

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