JP2006103149A - Resin molding with metallic tone and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin molding having a metallic tone which can ensure predetermined strength and in which appearance defects can be prevented, and to provide its manufacturing method. <P>SOLUTION: The resin molding 1 having a metallic tone is equipped with a core layer consisting of a synthetic resin containing metal powders and a skin layer 3 consisting of a synthetic resin containing metal powders and formed on the surface of the core layer, and the resin molding is characterized in that weld lines of the core layer and weld lines of the skin layer 3, which have generated respectively on the core layer and the skin layer 3 in molding the core layer and the skin layer 3, extend to different directions. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a metallic tone resin molded article and a method for producing a metallic tone resin molded article.

The conventional metallic resin molded product is molded by injection molding using a synthetic resin containing metal powder. When injection molding, this metallic resin molded product has weld lines formed at and near the junction of the synthetic resin when the flow direction of the synthetic resin is diversified due to, for example, the presence of a hole in the center. Is done.
Here, the weld line is made of a synthetic resin layer not containing metal powder. When a synthetic resin containing a metal powder is injected into a mold, this weld line allows the flowing synthetic resins to flow at a synthetic resin merging point, for example, at a position facing a synthetic resin injection port in a metallic resin molded product. After the collision, only the synthetic resin having a fluidity different from that of the metal powder flows without containing the metal powder to form a synthetic resin layer not containing the metal powder.

This weld line causes a defect in the appearance of the metallic resin molded product. Accordingly, various methods have been proposed in order to prevent the occurrence of weld lines on the surface of the metallic tone resin molded product. For example, there is a method in which a metallic pigment is blended in a paint and the paint is applied to the surface of a molded product to prevent defects in appearance due to the occurrence of weld lines. There is also a method of preventing irregular appearance due to the occurrence of weld lines by attaching amorphous polymer particles obtained by precipitation polymerization to fine particles such as metallic powder having gloss (see Patent Document 1).
JP 2001-262003 A

  By the way, although a metallic resin molded product in which a coating containing a metallic pigment is coated on its surface can prevent defects in appearance due to a weld line, the painting process takes time and cost. On the other hand, in the metallic tone resin molded product as shown in Patent Document 1, although the painting process is not required and the occurrence of weld lines can be prevented, the blending amount of the metallic pigment is limited to a predetermined amount in order to obtain a predetermined strength. It takes a lot of time to manufacture it. Therefore, a metallic resin molded product that can ensure a predetermined strength with a simple manufacturing method is desired.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a metallic resin molded product that can ensure a predetermined strength and prevent defects in appearance, and a method for manufacturing the same.

  The present invention employs the following means in order to solve the above problems. That is, the metallic resin molded product according to the present invention includes a core layer made of a synthetic resin containing a metal powder, and a skin layer made of a synthetic resin containing a metal powder and molded on the surface of the core layer. And when forming the said skin layer, the weld line which generate | occur | produced in each of the said core layer and the said skin layer extends in a different direction, It is characterized by the above-mentioned.

  Moreover, the metallic tone resin molded product according to the present invention is characterized in that the skin layer is molded to be thinner than the core layer.

  Further, in the metallic-tone resin molded product according to the present invention, the skin layer is molded to have a predetermined thickness or less.

In the core layer and the skin layer formed on the surface thereof, a weld line is generated so as to extend in a predetermined direction. By extending these weld lines in different directions, the weld line of the core layer is covered with the skin layer at a position where the weld line of the skin layer is not generated. Therefore, the weld line of the core layer does not appear on the appearance of the metallic tone resin molded product. Further, the weld line of the skin layer appears above the position where the weld line of the core layer is not generated. Therefore, even if the weld line of the skin layer appears in the appearance of the metallic resin molded product, it is offset by the metallic color of the core layer surface that can be seen through the weld line of the skin layer, and the weld line of the skin layer Disappears.
Here, if the skin layer is formed so as to be thinner than the core layer, the weld line of the skin layer becomes less visible. Furthermore, when the skin layer is molded to a predetermined thickness or less, the effect that the weld line of the skin layer is not visually recognized appears significantly.

  Further, in both the core layer and the skin layer, the weld line extends in a certain direction, so that the strength in the core layer and the skin layer is biased. Therefore, by integrally forming the core layer and the skin layer in which the weld lines extend in different directions, the unevenness of the strength in the core layer and the skin layer is made uniform.

  In the metallic-tone resin molded product according to the present invention, the synthetic resin used for the core layer and the synthetic resin used for the skin layer are made of the same material.

  The synthetic resin used for the core layer and the synthetic resin used for the skin layer are made of the same material, so that the adhesion between the core layer and the skin layer is improved, and there is more unevenness of strength in the core layer and the skin layer. To be leveled.

  In the metallic-tone resin molded product according to the present invention, the synthetic resin used for the core layer and the synthetic resin used for the skin layer are made of different materials.

  To obtain a metallic resin molded product for the purpose of improving strength, heat resistance, or chemical resistance, for example, by using different materials for the synthetic resin used for the core layer and the synthetic resin used for the skin layer If necessary, a synthetic resin of a different material can be selected to form a metallic resin molded product.

  Moreover, the manufacturing method of the metallic tone resin molded product according to the present invention includes a primary core layer molding step of molding a core layer by injecting a synthetic resin containing a metal powder into a core layer molding die, and the core A secondary skin for forming a skin layer on the surface of the core layer by replacing the layer molding die with a skin layer molding die and injecting a synthetic resin containing metal powder into the skin layer molding die A layer molding step, and when the synthetic resin is injected in the secondary skin layer molding step, the synthetic resin is injected into a position different from the position where the synthetic resin is injected in the primary core layer molding step. To do.

  When the core layer and the skin layer are formed by injecting a synthetic resin containing metal powder into the mold, a weld line is generated so as to extend in a predetermined direction. Therefore, when the synthetic resin is injected in the secondary skin layer molding process for molding the skin layer, the synthetic resin is injected at a position different from the position where the synthetic resin is injected in the primary core layer molding process for molding the core layer. These weld lines extend in different directions. Therefore, the weld line of the core layer is covered with the skin layer at a position where the weld line of the skin layer is not generated. Therefore, the weld line of the core layer does not appear on the appearance of the metallic tone resin molded product. Further, the weld line of the skin layer appears above the position where the weld line of the core layer is not generated. Therefore, even if the weld line of the skin layer appears in the appearance of the metallic resin molded product, it is offset by the metallic color of the core layer surface that can be seen through the weld line of the skin layer, and the weld line of the skin layer Disappears.

  Further, in both the core layer and the skin layer, the weld line extends in a certain direction, so that the strength in the core layer and the skin layer is biased. Therefore, by integrally forming the core layer and the skin layer in which the weld lines extend in different directions, the unevenness of the strength in the core layer and the skin layer is made uniform.

  Further, the method for producing a metallic-tone resin molded product according to the present invention includes a primary skin layer molding step of molding a skin layer by injecting a synthetic resin containing metal powder into a skin layer molding die, and the skin A secondary core in which a core layer is molded on the back surface of the skin layer by replacing the layer molding die with a core layer molding die and injecting a synthetic resin containing metal powder into the core layer molding die. A layer molding step, and when the synthetic resin is injected in the secondary core layer molding step, the synthetic resin is injected into a position different from the position where the synthetic resin is injected in the primary skin layer molding step. To do.

  When the core layer and the skin layer are formed by injecting a synthetic resin containing metal powder into the mold, a weld line is generated so as to extend in a predetermined direction. Therefore, when the synthetic resin is injected in the secondary core layer forming process for forming the core layer, the synthetic resin is injected at a position different from the position where the synthetic resin is injected in the primary skin layer forming process for forming the skin layer. These weld lines extend in different directions. Therefore, the weld line of the core layer is covered with the skin layer at a position where the weld line of the skin layer is not generated. Therefore, the weld line of the core layer does not appear on the appearance of the metallic tone resin molded product. Further, the weld line of the skin layer appears above the position where the weld line of the core layer is not generated. Therefore, even if the weld line of the skin layer appears in the appearance of the metallic resin molded product, it is offset by the metallic color of the core layer surface that can be seen through the weld line of the skin layer, and the weld line of the skin layer Disappears.

  Further, in both the core layer and the skin layer, the weld line extends in a certain direction, so that the strength in the core layer and the skin layer is biased. Therefore, by integrally forming the core layer and the skin layer in which the weld lines extend in different directions, the unevenness of the strength in the core layer and the skin layer is made uniform.

According to the metallic tone resin molded product of the present invention, the weld line of the core layer does not appear in the appearance of the metallic tone resin molded product, and the weld line of the skin layer is offset by the metallic color on the surface of the core layer and is not visually recognized. Therefore, appearance defects can be prevented.
Moreover, since the intensity | strength unevenness in a core layer and a skin layer is leveled, the predetermined intensity | strength of a metallic tone resin molded product can be ensured.

  In addition, according to the metallic tone resin molded product of the present invention, the adhesion between the core layer and the skin layer is improved, and the unevenness of the strength in the core layer and the skin layer is more even, so the metallic tone resin molded product The strength of can be improved.

  Further, according to the metallic tone resin molded product of the present invention, it is possible to mold a metallic tone resin molded product by selecting a synthetic resin of a different material as necessary. A molded resin molded product can be molded.

Further, according to the method for producing a metallic tone resin molded product of the present invention, the weld line of the core layer does not appear in the appearance of the metallic tone resin molded product, and the weld line of the skin layer cancels the metallic color on the surface of the core layer. Since it is not visually recognized, the appearance defect can be prevented.
Moreover, since the intensity | strength unevenness in a core layer and a skin layer is leveled, the predetermined intensity | strength of a metallic tone resin molded product can be ensured.

Embodiments of the present invention will be described below with reference to the drawings.
1 and 2 are views showing a metallic resin molded product to which the present invention is applied, that is, a resin molded product having a metallic appearance.
The resin molded product 1 is formed by being divided into two layers by two-color molding, and includes a core layer 2 and a skin layer 3.

  As shown in FIGS. 3 and 4, the core layer 2 is attached so as to surround the outer edge of the flat plate portion 22 and the flat plate portion 22 having a through hole 21 in the center, and is inclined while being inclined downward from the plane of the flat plate portion 22. And a rib 24 attached to the back surface of the flat plate portion 22 and disposed so that both ends thereof are in contact with the back surface of the outer edge portion 23. The core layer 2 is made of a synthetic resin containing metal powder, for example, aluminum powder. The synthetic resin for the core layer 2 is preferably a thermoplastic resin such as polycarbonate, ABS resin, or polypropylene.

  As shown in FIGS. 5 and 6, the skin layer 3 is attached so as to surround the outer edge of the flat plate portion 32 and a flat plate portion 32 having a through hole 31 having the same diameter as the through hole 21 at the center. And an outer edge portion 33 extending outward while being inclined further downward. The skin layer 3 is formed so as to cover the surface of the core layer 2, and the flat plate portion 32 is in close contact with the flat plate portion 22 and the outer edge portion 33 is in close contact with the outer edge portion 23. The skin layer 3 is made of a synthetic resin containing metal powder, for example, aluminum powder. The synthetic resin for the skin layer 3 is preferably a thermoplastic resin such as polycarbonate, ABS resin, or polypropylene. The synthetic resin for the skin layer 3 is made of the same material as the synthetic resin used for the core layer 2, but may be made of a different material. The skin layer 3 is formed to be thinner than the core layer 2. In addition, it is preferable that the skin layer 3 is shape | molded by predetermined thickness, for example, 0.6 mm or less.

When manufacturing the resin molded product 1 having the above-described configuration, after the core layer 2 is injection-molded by two-color molding as a primary molding process, the skin layer 3 is formed so as to cover the surface of the core layer 2 as a secondary molding process. Injection molding. That is, the resin molded product 1 is manufactured using the following procedure.
As shown in FIG. 7, a cavity 42 having a space 43 in the shape of the core layer 2 is positioned so as to be joined to the core 41. Then, the core layer 2 is injection molded by injecting a synthetic resin containing metal powder into the space 43 (primary core layer molding step). The core 41 and the cavity 42 are used as a core layer molding die.

  Here, when the core layer 2 is injection-molded in the core 41 and the cavity 42, if the synthetic resin containing the metal powder flows from the injection start position 2a below the outer edge portion 23 shown in FIG. Then, it flows so as to detour in two directions of the outer edge of the flat plate portion 22. Then, at the position facing the injection start position 2a, the synthetic resin containing the metal powder flowing in two directions collides with each other to generate a weld line 25. The weld line 25 extends from the through hole 21 in a predetermined direction, that is, outward with respect to the injection start position 2a.

  Then, after removing the cavity 42 from the core 41, as shown in FIG. 8, the cavity 44 having the space 45 in the shape of the skin layer 3 is positioned so as to be joined to the core 41. That is, the cavity 42 positioned in the core 41 is replaced with the cavity 44. At this time, the core layer 2 molded in the primary molding process is present in the space 45. Then, the skin layer 3 is injection-molded so as to cover the surface of the core layer 2 by injecting a synthetic resin containing metal powder into the space 45 (secondary skin layer molding step). The core 41 and the cavity 44 are used as a skin layer molding die.

Here, when the skin layer 3 is injection-molded in the core 41 and the cavity 44, if the synthetic resin containing the metal powder flows from the injection start position 3a below the outer edge 33 shown in FIG. Then, it flows so as to detour in two directions of the outer edge of the flat plate portion 32. Then, at a position facing the injection start position 3a, the synthetic resin containing the metal powder flowing in two directions collides with each other to generate a weld line 35. The weld line 35 extends from the through hole 31 in a predetermined direction, that is, outward with respect to the injection start position 3a.
Moreover, when the injection start position 2a of the core layer 2 and the injection start position 3a of the skin layer 3 are arranged at different positions, when the core layer 2 and the skin layer 3 are injection-molded, the synthetic resin containing the metal powder is different. Since it is injected from the position, the weld line 25 of the core layer 2 and the weld line 35 of the skin layer 3 extend in different directions.

  In this case, the weld line 25 of the core layer 2 and the weld line 35 of the skin layer extend in different directions, so that the weld line 25 of the core layer 2 is different from the position where the weld line 35 of the skin layer 3 is generated. The skin layer 3 is covered at the position. Therefore, the weld line 25 of the core layer 2 does not appear on the appearance of the resin molded product 1. Further, the weld line 35 of the skin layer 3 appears on the upper side of the position different from the position where the weld line 25 of the core layer 2 is generated. Therefore, even if the weld line 35 of the skin layer 3 appears in the appearance of the resin molded product 1, it is offset by the metallic color of the surface of the core layer 2 that can be seen through the weld line 35 of the skin layer 3, The weld line 35 of the skin layer 3 is not visually recognized. Accordingly, it is possible to prevent defects in appearance due to the generation of the weld line 25 of the core layer 2 and the weld line 35 of the skin layer 3 in the resin molded product 1.

In the resin molded product 1, when the core layer 2 and the skin layer 3 are injection-molded, the synthetic resin at the time of injection molding flows in addition to the weld line 25 of the core layer 2 and the weld line 35 of the skin layer 3. When the resin thickness of the resin molded product 1 changes, a flow stripe of a synthetic resin, a so-called flow mark may be formed. However, this flow mark is also not visually recognized due to the same effect as the weld line 25 of the core layer 2 and the weld line 35 of the skin layer 3, and the appearance defect can be prevented.
Here, when the skin layer 3 is formed so as to be thinner than the core layer 2 and further the skin layer 3 is formed to a predetermined thickness, for example, 0.6 mm or less, the weld line 35 of the skin layer 3 and the above-described flow mark are visually recognized. The effect that it is not performed appears remarkably.

  Further, in both the core layer 2 and the skin layer 3, the weld line 25 and the weld line 35 extend in a certain direction, so that the strength in the core layer 2 and the skin layer 3 is biased. Therefore, by integrally forming the core layer 2 and the skin layer 3 in which the weld line 25 and the weld line 35 extend in different directions, the intensity deviation in the core layer 2 and the skin layer 3 is complemented and balanced. It becomes. Therefore, the predetermined strength of the resin molded product 1 can be ensured.

  Moreover, since the weld line 35 of the skin layer 3 is not visually recognized by molding the resin molded product 1 into two layers of the core layer 2 and the skin layer 3, a metallic pigment is used to express a metallic tone on the surface of the skin layer 3. The painting process of painting is omitted. Therefore, it is possible to reduce labor and cost caused by requiring a painting process.

Further, since the synthetic resin used for the core layer 2 and the synthetic resin used for the skin layer 3 are made of the same material, the adhesion between the core layer 2 and the skin layer 3 is improved, and the core layer 2 and the skin layer are also improved. Intensity deviations in 3 are easily complemented with each other and are more evenly balanced. Therefore, the strength of the resin molded product 1 can be improved.
On the other hand, since the synthetic resin used for the core layer 2 and the synthetic resin used for the skin layer 3 are made of different materials, for example, a resin molded product 1 intended to improve strength, heat resistance, or chemical resistance can be obtained. In order to obtain the resin molded product 1, it is possible to select a synthetic resin of a different material as necessary and to mold the resin molded product 1. Therefore, the resin molded product 1 made of various kinds of materials can be molded.

  In addition, in the said embodiment, when manufacturing the resin molded product 1, you may interchange a primary molding process and a secondary molding process. In this case, the skin layer 3 is injection molded using the primary molding process as the skin layer molding process, and then the core layer 2 is injection molded so as to cover the back surface of the skin layer 3 using the secondary molding process as the core layer molding process. That is, when manufacturing the resin molded product 1 having the above-described configuration, the skin layer 3 is injection-molded by two-color molding using the following procedure, and then the core layer 2 is injected so as to cover the back surface of the skin layer 3. Mold.

  As shown in FIG. 9, the cavity 51 is joined to the core 52 so as to form a space 53 in the shape of the skin layer 3. Then, the skin layer 3 is injection-molded by injecting a synthetic resin containing metal powder into the space 53 (primary skin layer molding step). The cavity 51 and the core 52 are used as a skin layer molding die.

  Here, when the skin layer 3 is injection-molded in the cavity 51 and the core 52, if the synthetic resin containing the metal powder flows from the injection start position 3a below the outer edge portion 33 shown in FIG. Then, it flows so as to detour in the two directions of the outer edge of the flat plate portion 32. Then, a synthetic resin containing metal powder flowing in two directions collides with the injection start position 3a to generate a weld line 35. The weld line 35 extends from the through hole 31 in a predetermined direction, that is, outward with respect to the injection start position 3a.

  Then, after removing the core 52 from the cavity 51, as shown in FIG. 10, the core 54 is joined to the cavity 51 so as to form a space 55 having the shape of the core layer 2. That is, the core 52 positioned in the cavity 51 is replaced with the core 54. At this time, the skin layer 3 formed in the primary skin layer forming step exists in the space 55. And the core layer 2 is injection-molded so that the back surface of the skin layer 3 may be covered by inject | pouring the synthetic resin containing metal powder in the space 55 (secondary core layer molding process). The cavity 51 and the core 54 are used as a skin layer molding die.

Here, when the core layer 2 is injection-molded in the cavity 51 and the core 54, if the synthetic resin containing metal powder flows from the injection start position 2a below the outer edge 23 shown in FIG. Then, it flows so as to detour in two directions of the outer edge of the flat plate portion 22. Then, at the position facing the injection start position 2a, the synthetic resin containing the metal powder flowing in two directions collides with each other to generate a weld line 25. The weld line 25 extends from the through hole 21 in a predetermined direction, that is, outward with respect to the injection start position 2a.
In this case, the same operation and effect as in the above embodiment can be obtained, and the description thereof is omitted.

In the above embodiment, the resin molded product 1 is manufactured by two-color molding, but the weld line 25 generated in the core layer 2 and the weld line 35 generated in the skin layer 3 are in different directions. If the core layer 2 and the skin layer 3 are molded so as to extend, they may not be manufactured by two-color molding.
In the above embodiment, if the injection start position 2a of the core layer 2 and the injection start position 3a of the skin layer 3 for injecting synthetic resin containing metal powder during injection molding are different positions, the core The injection start position 2a of the layer 2 and the injection start position 3a of the skin layer 3 may be any positions.

  Moreover, in the said embodiment, the metal powder contained in a synthetic resin is not restricted to an aluminum powder, Metals, such as gold | metal | money, silver, copper, nickel, and these alloys may be sufficient. The synthetic resin is not limited to the thermoplastic resin other than the synthetic resin described above, and may contain an additive such as a colorant as necessary.

It is a perspective view of the metallic tone resin molded product which concerns on embodiment in this invention. It is sectional drawing of the metallic tone resin molded product which concerns on embodiment in this invention. It is a perspective view of the core layer of the metallic tone resin molded product which concerns on embodiment. It is sectional drawing of the core layer of the metallic tone resin molded product which concerns on embodiment. It is a perspective view of the skin layer of the metallic tone resin molded product which concerns on embodiment. It is sectional drawing of the skin layer of the metallic tone resin molded product which concerns on embodiment. It is sectional drawing of the metal mold | die for core layer shaping | molding which shape | molds the core layer which concerns on embodiment. It is sectional drawing of the metal mold | die for skin layer shaping | molding which shape | molds the skin layer which concerns on embodiment. It is sectional drawing of another metal mold | die for skin layer shaping | molding which shape | molds the skin layer which concerns on embodiment. It is sectional drawing of another metal mold | die for core layer shaping | molding which shape | molds the core layer which concerns on embodiment.

Explanation of symbols

1 Resin molded product (metallic resin molded product)
2 Core layer 3 Skin layer 25 Weld line (of core layer) 35 Weld line (of skin layer) 41 Core (mold for core layer molding, mold for skin layer molding)
42 cavity (core layer mold)
44 Cavity (Skin Layer Mold)
51 cavity (mold for core layer molding, mold for skin layer molding)
52 Core (mold for core layer molding)
54 Core (mold for skin layer molding)

Claims (7)

A core layer made of a synthetic resin containing metal powder;
A skin layer made of a synthetic resin containing metal powder and molded on the surface of the core layer,
A metallic resin molded product, wherein weld lines generated in the core layer and the skin layer respectively extend in different directions when the core layer and the skin layer are molded.     The metallic skin resin molded product according to claim 1, wherein the skin layer is molded to be thinner than the core layer.     The metallic skin resin molded product according to claim 2, wherein the skin layer is molded to have a predetermined thickness or less.     4. The metallic resin molded product according to claim 1, wherein the synthetic resin used for the core layer and the synthetic resin used for the skin layer are made of the same material. 5.     The synthetic resin used for the said core layer and the synthetic resin used for the said skin layer consist of different materials, The metallic tone resin molded product of any one of Claim 1 to 3 characterized by the above-mentioned. A primary core layer molding step of molding the core layer by injecting a synthetic resin containing metal powder into the core layer molding die;
The core layer molding die is replaced with a skin layer molding die, and a synthetic resin containing metal powder is injected into the skin layer molding die to mold the skin layer on the surface of the core layer 2 With the following skin layer molding process,
When the synthetic resin is injected in the secondary skin layer molding step, the synthetic resin is injected into a position different from the position where the synthetic resin is injected in the primary core layer molding step. Production method. A primary skin layer molding step of molding a skin layer by injecting a synthetic resin containing metal powder into a skin layer molding die;
2. Replacing the skin layer molding die with a core layer molding die, and molding a core layer on the back surface of the skin layer by injecting a synthetic resin containing metal powder into the core layer molding die 2 A next core layer forming step,
When the synthetic resin is injected in the secondary core layer molding step, the synthetic resin is injected into a position different from the position where the synthetic resin is injected in the primary skin layer molding step. Production method.

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