JP6771873B2 - Resin molded products and their manufacturing methods - Google Patents

Description

The present invention relates to a resin molded product provided with a laminated portion having at least a first layer and a second layer, and a method for producing the resin molded product.

Like the vehicle panel of Patent Document 1, a member having a multi-layer structure composed of a hard base material layer (first layer) and a soft skin layer (second layer) that covers the base material layer as a whole. is there. It has been proposed that such a vehicle panel integrally forms a base material layer and a skin layer by two-color molding. Explaining the method of manufacturing a vehicle panel by two-color molding, the first resin is injected into the first cavity defined by the first mold and the second mold, and the first resin is used as the first color, for example. Form the material layer. The second mold is removed, the third mold is closed with respect to the first mold in which the base material layer is left, and the third mold is defined between the base material layer and the third mold. The second resin is injected into the cavity of No. 2 to form a second color skin layer on the base material layer. According to the two-color molding, it is possible to manufacture a vehicle panel having a multi-layer structure made of different resins with one mold device, and it is possible to save the trouble of combining and adhering the base material layer and the skin layer. ..

Japanese Unexamined Patent Publication No. 2001-26036

In the vehicle panel obtained by the above-mentioned two-color molding, after the first color base material layer is molded and shrunk, the second color skin layer is injection-molded on the base material layer, so that the base material layer shrinks. It remains as stress, and as a result, the obtained vehicle panel is deformed such as warping.

That is, the present invention has been proposed in view of the above-mentioned problems related to the prior art, and an object of the present invention is to provide a resin molded product with suppressed deformation and a method for producing the same.

In order to overcome the above-mentioned problems and achieve the intended purpose, the resin molded product of the invention according to claim 1 of the present application is used.
A resin molded product having a laminated portion having a first layer formed of a first resin and a second layer integrally formed by overlapping the front side of the first layer with a second resin. ,
Each of the back surfaces is formed in a concave shape that opens to the back side of the laminated portion composed of the first layer, and includes a plurality of shrinkage regulating portions arranged corresponding to the outer edge of the laminated portion.
The plurality of shrinkage restricting portions are arranged along the entire outer edge of the laminated portion at a portion deviated from the center of the laminated portion to the outer edge side, and a line connecting adjacent shrinkage regulating portions is the outer edge of the laminated portion. Arranged to resemble ,
The gist is that the plurality of shrinkage regulating portions are arranged in a range of 10 mm to 30 mm from the outer edge of the laminated portion along which the shrinkage regulating portion is aligned .
According to the first aspect of the present invention, by forming the shrinkage restricting portion corresponding to the outer edge of the laminated portion, it is possible to suppress the shrinkage of the first layer in the mold and prevent the laminated portion from being deformed. Further, by forming the shrinkage regulating portion on the portion unevenly distributed toward the outer edge side of the laminated portion, the shrinkage of the first layer that occurs from the outer edge side to the central side of the laminated portion can be further suppressed. Further, by forming the shrinkage regulating portion corresponding to the entire outer edge of the laminated portion, the shrinkage of the first layer can be suppressed over the entire laminated portion.

The gist of the invention according to claim 2 is that the shrinkage control portion is formed so as to reach the second layer from the back surface of the first layer.
According to the invention of claim 2, the shrinkage of the first layer can be further suppressed by forming the shrinkage regulating portion so as to reach from the first layer to the second layer.

In the invention according to claim 3 , the opening opened to the back side of the laminated portion in the shrinkage restricting portion is formed in a rectangular shape having a long side extending along the outer edge of the laminated portion along which the shrinkage regulating portion is aligned. Is the gist.

In order to overcome the above-mentioned problems and achieve the intended purpose, the method for producing a resin molded product according to claim 4 of the present application is:
A method for producing a resin molded product having a laminated portion having a first layer formed of a first resin and a second layer integrally formed by overlapping the front side of the first layer with a second resin. And
The first resin is injected into the first cavity defined between the common mold portion and the primary mold portion, and in the first cavity, a plurality of ridges provided in the common mold portion are provided on the back side of the laminated portion. A first layer having a concave shape to be opened and having a plurality of shrinkage restricting portions arranged along the outer edge of the laminated portion is formed.
The ridge is fitted into the shrinkage restricting portion, the primary mold portion is replaced with the secondary mold portion while the first layer is left in the common mold portion, and the second mold portion is sandwiched between the secondary mold portion and the first layer. Two cavities are defined, or the primary mold portion is separated from the common mold portion, a second cavity is defined between the primary mold portion and the first layer, and a second resin is injected into the second cavity. Then, the second layer is formed on the front side of the first layer in the second cavity.
When molding the first layer, the plurality of shrinkage restricting portions are arranged along the entire outer edge of the laminated portion at a portion deviated from the center of the laminated portion to the outer edge side, and adjacent shrinkage restricting portions are formed. The line connecting the two is formed so as to resemble the outer edge of the laminated portion .
The gist is that the plurality of shrinkage regulating portions are arranged in a range of 10 mm to 30 mm from the outer edge of the laminated portion along which the shrinkage regulating portion is aligned .
According to the invention of claim 4 , when the first layer is molded, the shrinkage regulating portion is formed and the inside of the mold of the first layer is held in the common mold portion by the ridges fitted in the shrinkage regulating portion. It is possible to suppress the shrinkage in the first layer and prevent the deformation of the laminated portion due to the shrinkage difference between the first layer and the second layer. Further, the shrinkage of the first layer that occurs from the outer edge side to the center side of the laminated portion is suitably suppressed by the ridges that fit into the plurality of shrinkage restricting portions formed at the portion deviated from the center of the laminated portion to the outer edge side. be able to. Further, shrinkage can be suppressed over the entire first layer by the ridges fitted in the shrinkage restricting portion formed corresponding to the entire outer edge of the laminated portion.

The gist of the invention according to claim 5 is that the protrusions protruding from the front side of the first layer form the shrinkage regulating portion extending from the first layer to the second layer.
According to the invention of claim 5 , when the first layer is molded, the ridges fitted in the shrinkage regulating portion extend all over the thickness direction of the first layer, so that the shrinkage of the first layer Can be further suppressed.

The gist of the invention according to claim 6 is to form an opening in the shrinkage restricting portion that opens to the back side of the laminated portion in a rectangular shape having a long side extending along the outer edge of the laminated portion along which the shrinkage restricting portion is aligned. And.

According to the resin molded product according to the present invention, deformation of the laminated portion can be suppressed. According to the method for producing a resin molded product according to the present invention, it is possible to obtain a resin molded product having a laminated portion in which deformation is suppressed.

It is a schematic perspective view which shows the instrument panel provided with the glove box which concerns on embodiment of this invention. It is a schematic perspective view which shows the glove box of an Example. It is a rear view which shows schematic the outer member of the lid of an Example. It is a rear view which shows the main part of the outer member of an Example roughly. FIG. 4 is a cross-sectional view taken along the line AA of FIG. It is explanatory drawing which shows schematic manufacturing process of the outer member of an Example. (a) is a front view schematically showing the outer member of the modified example, and (b) is an enlarged view of part B of (a). It is the schematic perspective view which shows by breaking the main part of the outer member of the modified example.

Next, a resin molded product and a method for producing the same according to the present invention will be described below with reference to the accompanying drawings with reference to suitable examples. In the embodiment, the outer member 26 of the lid 24 in the glove box 20 as shown in FIGS. 1 and 2, which is one of the vehicle interior members, will be described as a resin molded product. Here, in the outer member (resin molded product) 26, the side facing the surface to be the design surface is referred to as the front side, and the side facing the attachment surface to the other member (inner member 28 in the embodiment) is referred to as the back side. For example, in the case of the glove box 20, the passenger compartment side facing the design surface is the front side, and the vehicle body side to which the glove box 20 is attached is the back side.

As shown in FIGS. 1 and 2, the glove box 20 according to the embodiment is arranged inside the instrument panel 10 and has a box-shaped box body 22 open to the passenger compartment side and a lower portion of the box body 22. It is composed of a lid 24 which is connected to the box body 22 via a hinge and opens and closes the opening of the box body 22. The glove box 20 is configured such that the lid 24 forms a part of the design surface of the instrument panel in a closed posture with the opening of the box body 22 closed, and the lid 24 is held in the closed posture by a locking device (not shown). Will be done. Further, the glove box 20 can be tilted toward the passenger compartment side with the hinge at the lower part of the lid 24 as a fulcrum to open the opening of the box body 22 by operating the operation button 30 to release the lock by the lock device. The lid 24 is composed of an outer member (resin molded product) 26 that constitutes a front surface facing the passenger compartment, and an inner member 28 that is attached to the back side of the outer member 26 and constitutes the back surface facing the inside of the box body 22. ing.

As shown in FIG. 5, the outer member 26 has a first layer (base material layer) 34 constituting the back surface of the outer member 26 and a second layer (skin) formed on the front side of the first layer 34. The main body portion is composed of a laminated portion 32 having a multi-layer structure having the layer) 36. The laminated portion 32 is a substantially rectangular plate-like body in which a notch for accommodating the operation button 30 is formed in one of the upper edge corners (see FIG. 3), and the second layer 36 forming the design surface of the outer member 26. The surface of the is formed to imitate a skin material such as leather. Further, in the laminated portion 32, the first layer 34 formed of the first resin and the second layer 36 formed of the second resin overlap in the plate thickness direction, and the second layer is cured from the second resin. The first layer 34 and the second layer 36 are integrated by the bonding force of the layer 36 itself.

As the resin forming the first layer 34 and the second layer 36, various resins can be adopted. For example, the first layer 34 and the second layer 36 may be made of the same material or different materials such as a thermoplastic elastomer (TPE) such as polypropylene (PP), polyethylene (PE), and an olefin elastomer (TPO). be able to. In the examples, the first layer 34 is made of polypropylene and the second layer 36 is made of an olefin elastomer.

As shown in FIGS. 4 and 5, each of the laminated portions 32 is formed in a concave shape that opens to the back side of the laminated portion 32, and a plurality of shrinkage restrictions that are intermittently arranged so as to correspond to the outer edge 32a of the laminated portion 32. The part 38 is provided. The shrinkage regulating portion 38 is a bottomed recess that opens to the back surface of the first layer 34 without opening to the front side of the laminated portion 32, and in the embodiment, reaches the second layer 36 from the back surface of the first layer 34. It is formed. In the embodiment, the shrinkage regulating portion has a depth of 0.5 mm to 0.8 mm and the second layer 36 remains in the laminated portion 32 having a plate thickness of 4 mm (first layer 2.5 mm, second layer 1.5 mm). 38 is formed. The shrinkage regulating portion 38 is formed so that the opening width becomes narrower from the back side (opening side of the shrinkage regulating portion 38) to the front side (bottom side of the shrinkage regulating portion 38) of the laminated portion 32, and the shrinkage regulating portion 38 is defined. The formed wall is tilted in a range of 3 ° to 10 ° (10 ° in the example) with respect to the plate thickness direction of the laminated portion 32. The opening shape of the shrinkage regulating portion 38 can be a polygon such as a quadrangle, a round shape, an ellipse, or another shape. In the embodiment, the opening shape of the shrinkage regulating portion 38 is the corresponding outer edge of the laminated portion 32. It is formed in a rectangular shape with a long side extending along 32a (see FIG. 4). The shrinkage regulating portion 38 preferably sets the opening on the back surface of the first layer 34 in the range of 5 mm to 10 mm on the long side (10 mm in the example) and 2 mm to 4 mm on the short side (4 mm in the example). ..

As shown in FIG. 3, in the laminated portion 32 of the embodiment, a plurality of shrinkage regulating portions 38 are provided side by side along the entire circumference of the upper, lower, left and right outer edges 32a, and a line connecting the adjacent shrinkage regulating portions 38 is a laminated portion. It is similar to the outer edge 32a of 32. Here, "a plurality of shrinkage regulating portions 38 are lined up corresponding to the outer edge 32a of the laminated portion 32" has a strict meaning as the outer edge 32a of the laminated portion 32 in which the line connecting the adjacent shrinkage regulating portions 38 is closest. This includes not only the case where the contraction regulating portions 38 are aligned with each other but also the case where the contraction regulating portions 38 are not attached to the outer edge 32a of the closest laminated portion 32 and are not separated from each other. Further, the plurality of shrinkage regulating portions 38 are arranged so as to be arranged in a portion deviated toward the outer edge side from the center of the laminated portion 32, and the shrinkage regulating portion 38 is within a range of 10 mm to 30 mm from the corresponding outer edge 32a of the laminated portion 32. It is preferable to arrange. When the shrinkage regulating portion 38 is arranged at a position farther from the corresponding outer edge 32a of the laminated portion 32 than 30 mm, the deformation preventing effect of the laminated portion 32 by the shrinkage regulating portion 38 is reduced on the outer edge 32a side of the shrinkage regulating portion 38. The arrangement condition of the laminated portion 32 of the shrinkage regulating portion 38 with respect to the outer edge 32a is based on a line passing through the center of the shrinkage regulating portion 38 in a direction orthogonal to the arrangement direction of the plurality of shrinkage regulating portions 38. Further, the distance between the adjacent shrinkage regulating portions 38 is preferably set in the range of 2 mm to 4 mm (4 mm in the embodiment), and is set smaller than the width in the direction along the outer edge 32a of the laminated portion 32 in the shrinkage regulating portion 38. It is desirable from the viewpoint of preventing deformation of the laminated portion 32.

Next, a method of manufacturing the outer member (resin molded product) 26 according to the embodiment will be described. In the embodiment, the outer member 26 having the first layer 34 and the second layer 36 is manufactured by two-color molding. The mold device used in the embodiment is arranged so as to face the common mold portion 40 provided so as to be movable between the first position and the second position and the common mold portion 40 in the first position. A primary mold portion 42 that moves forward and backward with respect to the common mold portion 40, and a secondary mold portion 44 that is arranged so as to face the common mold portion 40 at the second position and moves forward and backward with respect to the common mold portion 40. (See FIG. 6). By closing the common mold portion 40 and the primary mold portion 42, a first cavity 46 aligned with the first layer 34 is defined between the common mold portion 40 and the primary mold portion 42 (FIG. 6 (FIG. 6). a) See). At this time, the molding surface of the common mold portion 40 defines the back side of the first layer 34, while the molding surface of the primary mold portion 42 defines the front side of the first layer 34. Here, the molding surface of the common mold portion 40 is provided with a ridge 48 for molding the shrinkage regulating portion 38 described above, and the molding surface of the primary mold portion 42 is closed in accordance with the tip portion of the ridge 48. A recess 42a that can sometimes accept the tip is provided. By injecting the first resin into the first cavity 46 (FIG. 6 (b)) and curing the first resin in the first cavity 46, a part of the shrinkage regulating portion 38 (opening side) is formed by the ridge 48. ) Is formed on the first layer 34. In the embodiment, the first layer 34 is molded by the injection molding method.

In a state where the ridge 48 formed from a part of the shrinkage regulating portion 38 in the common mold portion 40 is fitted to the shrinkage regulating portion 38, the primary mold portion 42 is formed so that the first layer 34 remains in the common mold portion 40. Open (see FIG. 6 (c)). The common mold portion 40 is moved from the first position to the second position, and is replaced so as to face the secondary mold portion 44 from the primary mold portion 42. By closing the common mold portion 40 and the secondary mold portion 44, the second layer 36 held between the common mold portion 40 and the secondary mold portion 44 is aligned with the second layer 36. The cavity 50 is defined (see FIG. 6 (d)). At this time, the ridge 48 projecting to the front side of the first layer 34 via the contraction regulating portion 38 formed through the first layer 34 faces the second cavity 50. By injecting the second resin into the second cavity 50 (FIG. 6 (e)) and curing the second resin in the second cavity 50, a shrinkage regulating portion 38 communicating with the first layer 34 is formed. The second layer 36 is integrally molded with the first layer 34 (FIG. 6 (f)). In the embodiment, the second layer 36 is molded by an injection molding method.

[Action of Example]
Next, the operation of the examples will be described. According to the outer member 26 of the embodiment, the inside and outside of the shrinkage regulating portion 38 due to the presence of a plurality of shrinkage regulating portions 38 formed in a concave shape that opens to the back side of the laminated portion 32 and arranged corresponding to the outer edge 32a of the laminated portion 32. The first layer 34 can be separated by, and the shrinkage of the first layer 34 formed from the first resin can be suppressed. That is, the shrinkage difference between the second layer 36, which is laminated on the front side of the first layer 34 and formed from the second resin, and the first layer 34 is reduced to prevent deformation such as warpage of the laminated portion 32. Can be done. Further, by forming the shrinkage regulating portion 38 in the laminated portion 32 so as to reach the second layer 36 from the back surface of the first layer 34, the shrinkage regulating portion 38 exists over the entire plate thickness direction of the first layer 34. Therefore, the shrinkage of the first layer 34 can be further suppressed. Further, by forming the shrinkage restricting portion 38 at a portion biased toward the outer edge 32a side of the laminated portion 32, the shrinkage of the first layer 34 generated from the outer edge 32a side to the central side of the laminated portion 32 is caused along the outer edge 32a. It can be suppressed more appropriately by a plurality of contraction regulating portions 38 arranged side by side. Furthermore, by forming the shrinkage regulating portions 38 so as to line up with the entire circumference of the outer edge 32a of the laminated portion 32, the shrinkage of the first layer 34 can be uniformly suppressed over the entire laminated portion 32. As described above, in the outer member 26, the laminated portion 32 having a multi-layer structure composed of the first layer 34 and the second layer 36 is highly accurate and excellent in quality.

According to the manufacturing method of the embodiment, when the first layer 34 is formed in the first cavity 46, the shrinkage regulating portion 38 is formed and the ridge 48 fitted in the shrinkage regulating portion 38 causes the common mold portion 40. The shrinkage of the first layer 34 held by the resin can be suppressed, and the shrinkage of the first layer 34 formed from the first resin can be suppressed. Therefore, the shrinkage difference between the second layer 36, which is laminated on the front side of the first layer 34 and formed from the second resin, and the first layer 34 is reduced to prevent deformation such as warpage of the laminated portion 32. Can be done. Further, in a state where the ridge 48 is fitted to the shrinkage regulating portion 38 and held by the common mold portion 40 on the first layer 34 to suppress the shrinkage of the first layer, the first layer 34 and the secondary mold portion 44 In the second cavity 50 defined between the two, the second layer 36 is laminated on the first layer 34 from the second resin and integrally molded. Then, when the outer member 26 is taken out from the mold device, the first layer 34 and the second layer 36 that are separated from the ridge 48 shrink at the same time, so that the shrinkage between the first layer 34 and the second layer It is possible to suppress the difference and prevent the obtained laminated portion 32 from being deformed.

By forming the shrinkage regulating portion 38 on the laminated portion 32 so as to reach the second layer 36 from the back surface of the first layer 34 by the ridges of the common mold portion 40, the ridges 48 fitted into the shrinkage regulating portion 38 are The first layer 34 can be dammed over the entire plate thickness direction to further suppress the shrinkage of the first layer 34. Further, by forming the shrinkage restricting portion 38 at a portion biased toward the outer edge 32a side of the laminated portion 32, the shrinkage of the first layer 34 generated from the outer edge 32a side to the central side of the laminated portion 32 is along the outer edge 32a. It can be dammed more appropriately by the ridges 48 that define the plurality of contraction regulating portions 38 arranged side by side. Furthermore, by forming the shrinkage regulating portions 38 so as to line up with the entire circumference of the outer edge 32a of the laminated portion 32, the shrinkage of the first layer 34 can be uniformly suppressed over the entire laminated portion 32. As described above, in the outer member 26 obtained by the manufacturing method of the embodiment, the laminated portion 32 having a multi-layer structure composed of the first layer 34 and the second layer 36 is accurate and excellent in quality.

(Experiment)
The amount of deformation of the laminated portion was confirmed for the experimental examples and comparative examples set under the following conditions. In the experimental example and the comparative example, the laminated portion was formed in a square plate shape of 150 mm in length × 150 mm in width, the thickness (T1) of the first layer made of polypropylene was set to 2.5 mm, and the second layer made of an olefin elastomer was used. The layer thickness (T2) was set to 1.5 mm. In the experimental example, shrinkage control portions are formed at a depth reaching the second layer from the back surface of the first layer so that the residual thickness (T3) of the second layer is 0.8 mm, and each shrinkage regulation portion is laminated. The long side (K1: width in the alignment direction of the contraction regulating part) along the corresponding outer edge of is 4 mm, and the short side (K2: width in the direction orthogonal to the alignment direction of the contraction regulating portion) is 2.5 mm. It is formed in. The distance (L) between adjacent shrinkage control portions is set to 4 mm. Further, each shrinkage regulating portion is tapered (α) at an angle of 10 ° with respect to the plate thickness direction of the laminated portion so as to become narrower from the opening side toward the bottom. In the experimental example, a plurality of shrinkage restricting portions are formed so as to line up corresponding to the entire outer edge of the laminated portion, and the separation interval (W) from the corresponding outer edge is as shown in Table 1. On the other hand, in the comparative example, the contraction regulating portion is not provided. The experimental example and the comparative example were molded by the two-color molding method as described in the above example, and the obtained experimental example and the comparative example were deformed in the plate thickness direction between the center and the outer edge of the laminated portion. I confirmed that it was done. The results are shown in Table 1.

As shown in Table 1, it was confirmed that in the experimental example provided with the shrinkage regulating portion, the deformation of the laminated portion was smaller than that in the comparative example in which the shrinkage regulating portion was not provided.

(Change example)
Not limited to the above-described embodiment, it can be changed as follows, for example.
(1) The present invention can be applied not only to glove boxes but also to instrument panels, door trims, console boxes and other vehicle interior members as resin molded products. Further, the present invention can be applied not only to vehicle interior members but also to vehicle exterior members such as spoilers. It can also be applied to resin molded products other than those for vehicles.
(2) The resin molded product is not limited to the one composed entirely of laminated portions as in the examples, but may be partially composed of laminated portions having a multi-layer structure.
(3) The laminated portion is not limited to a two-layer structure, and may have a multi-layer structure of three or more layers.
(4) The shrinkage restricting portions are not limited to the configuration in which they are arranged in a row corresponding to the outer edge of the laminated portion, and two or more rows of shrinkage regulating portions may be formed corresponding to the outer edge of the laminated portion. In this case, in the direction orthogonal to the arrangement direction of the contraction regulating portions, even if the contraction regulating portions in the adjacent rows are arranged so as to coincide with each other or partially overlap each other, they do not overlap each other. It may be arranged in a staggered pattern.
(5) The shrinkage control portions may be all the same size, have the same size in an appropriate section, or may be all different in size.
(6) In the embodiment, a two-color molding method in which the primary mold portion and the secondary mold portion are exchanged with respect to the common mold portion is mentioned, but it is common by separating the primary mold portion from the common mold portion. A two-color molding method in which a second cavity is defined between the first layer held in the mold portion and the primary mold portion and the second cavity is filled with the second resin is also applicable.

As the resin molded product, as shown in FIGS. 7 and 8, a pseudo stitch pattern 52 may be formed. The laminated portion 32 is a first layer 34 in which a plurality of thread portions 54 projecting on the front side (design surface side) of the laminated portion 32 are formed, and a first layer in a state where the protruding ends of the thread portions 54 are exposed. The stitch pattern 52 is represented by the thread portion 54, which is composed of the second layer 36 formed so as to cover the 34 and faces the front side. In this case, the shrinkage regulating portion 38 may be provided in the first layer 34 in accordance with the thread portion 54 (see FIG. 8), or may be provided at a position deviated from the thread portion 54. The laminated portion 32 on which the stitch pattern 52 is formed can be manufactured as follows. The first resin is injected into the first cavity 46 defined between the common mold portion 40 and the primary mold portion 42, and in the first cavity 46, a plurality of thread portions 54 formed so as to project side by side and laminated. The first layer 34 is formed with the shrinkage regulating portions 38 lined up corresponding to the outer edge 32a of the portion 32. The ridge 48 formed by molding the shrinkage regulating portion 38 is fitted to the shrinkage regulating portion 38, and the primary mold portion 42 is replaced with the secondary mold portion 44 while leaving the first layer 34 in the common mold portion 40 to replace the secondary mold. The second resin may be injected into the second cavity 50 defined between the portion 44 and the common mold portion 40, and the second layer 36 may be formed on the front side of the first layer 34 in the second cavity 50.

32 Laminated part, 32a outer edge, 34 1st layer, 36 2nd layer, 38 shrinkage regulation part,
40 common mold part, 42 primary mold part, 44 secondary mold part, 46 first cavity, 48 ridges,
50 Second cavity

Claims (6)

A resin molded product having a laminated portion having a first layer formed of a first resin and a second layer integrally formed by overlapping the front side of the first layer with a second resin. ,
Each of the back surfaces is formed in a concave shape that opens to the back side of the laminated portion composed of the first layer, and includes a plurality of shrinkage regulating portions arranged corresponding to the outer edge of the laminated portion.
The plurality of shrinkage restricting portions are arranged along the entire outer edge of the laminated portion at a portion deviated from the center of the laminated portion to the outer edge side, and a line connecting adjacent shrinkage regulating portions is the outer edge of the laminated portion. Arranged to resemble ,
A resin molded product, wherein the plurality of shrinkage regulating portions are arranged in a range of 10 mm to 30 mm from the outer edge of the laminated portion along which the shrinkage regulating portion is aligned . The resin molded product according to claim 1, wherein the shrinkage regulating portion is formed so as to reach the second layer from the back surface of the first layer. The resin molding according to claim 1 or 2 , wherein the opening opened to the back side of the laminated portion in the shrinkage restricting portion is formed in a rectangular shape having a long side extending along the outer edge of the laminated portion along which the shrinkage regulating portion is aligned. Goods. A method for producing a resin molded product having a laminated portion having a first layer formed of a first resin and a second layer integrally formed by overlapping the front side of the first layer with a second resin. And
The first resin is injected into the first cavity defined between the common mold portion and the primary mold portion, and in the first cavity, a plurality of ridges provided in the common mold portion are provided on the back side of the laminated portion. A first layer having a concave shape to be opened and having a plurality of shrinkage restricting portions arranged along the outer edge of the laminated portion is formed.
The ridge is fitted into the shrinkage restricting portion, the primary mold portion is replaced with the secondary mold portion while the first layer is left in the common mold portion, and the second mold portion is sandwiched between the secondary mold portion and the first layer. Two cavities are defined, or the primary mold portion is separated from the common mold portion, a second cavity is defined between the primary mold portion and the first layer, and a second resin is injected into the second cavity. Then, the second layer is formed on the front side of the first layer in the second cavity.
When molding the first layer, the plurality of shrinkage restricting portions are arranged along the entire outer edge of the laminated portion at a portion deviated from the center of the laminated portion to the outer edge side, and adjacent shrinkage restricting portions are formed. The line connecting the two is formed so as to resemble the outer edge of the laminated portion .
A method for producing a resin molded product, which comprises arranging the plurality of shrinkage regulating portions in a range of 10 mm to 30 mm from the outer edge of the laminated portion along which the shrinkage regulating portions are aligned . The method for producing a resin molded product according to claim 4, wherein the shrinkage restricting portion reaching from the first layer to the second layer is formed by the ridge protruding from the front side of the first layer. The resin molded product according to claim 4 or 5 , wherein an opening opened to the back side of the laminated portion in the shrinkage restricting portion is formed in a rectangular shape having a long side extending along the outer edge of the laminated portion along which the shrinkage regulating portion is aligned. Production method.

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