JP6072597B2 - Plastic molded product - Google Patents

Description

  The present invention relates to a resin molded product in which a primary material made of a resin material and a secondary material made of a resin material are integrally formed.

  Conventionally, insert molding is known in which an insert is inserted into a mold and integrally molded with a molten resin. For example, as in Patent Document 1, a casing for an electronic device in which a metal main body and a plastic antenna cover are integrally formed by an insert molding method is known.

  Two-color molding is also known in which two or more molds are placed in one molding machine and molten resins of different materials or different colors only are injected and molded.

JP 2009-262530 A

  By the way, in the case of the electronic device casing described in Patent Document 1, when a plurality of antennas are provided, a sufficient antenna area cannot be ensured or the area of the metal main body becomes very small. For this reason, there is a problem that the meaning of using the metal is lost and the cost is high. In addition, since insert molding is once performed and taken out from the mold for shrinkage and cooling, warpage and other troubles are likely to occur.

  This invention is made | formed in view of this point, The place made into the objective is to reduce the residual stress at the time of secondary molding, and to prevent the curvature of a resin molded product.

  In order to achieve the above object, in the present invention, a ridge is provided on the primary material side corresponding to the thick portion of the secondary material.

  Specifically, the first invention is based on a resin molded product in which a primary material made of a resin material and a secondary material made of a resin material are integrally molded.

The primary material has a primary side plate-shaped main body and at least one ridge that protrudes perpendicularly to the primary side plate-shaped main body and whose longitudinal ends gently continue to the primary side plate-shaped main body,
The said secondary material shall have a thick part which covers the said protruding item | line at least.

  According to the above configuration, in the thick part of the secondary material, by enveloping the ridges of the primary material with the secondary material, the difference in thickness between the thick part and its surroundings can be minimized, and the resin The occurrence of sink marks due to shrinkage during cooling is effectively prevented. Moreover, since the molten resin of a secondary material flows smoothly into the circumference | surroundings of a protruding item | line by making the longitudinal direction both ends of a protruding item | line continue to a primary side plate-shaped main body gently, it is hard to generate | occur | produce a bubble and a curvature.

  As described above, according to the present invention, the primary material is provided with at least one ridge that is gently continuous with the primary side plate-like body at both ends in the longitudinal direction, and the secondary material is provided with a thick portion that covers at least the ridge. By providing, it is possible to reduce the substantial thickness of the secondary material in the thick portion, to reduce the residual stress during the secondary molding, and to prevent the resin molded product from warping.

It is the front view and its partially expanded view of the 2nd cabinet of the mobile telephone which concern on embodiment of this invention. The mobile phone which concerns on embodiment of this invention is shown, (a) is the perspective view seen from the front side, (b) is the perspective view seen from the back side. It is a disassembled perspective view which shows a mobile telephone. (A) is a front view which shows a cover part, (b) is a perspective view which shows a peripheral member. (A) is the Va-Va sectional view taken on the line of FIG. 1 and its partially expanded sectional view, and (b) is the Vb-Vb sectional view of FIG. 1 and its partially enlarged sectional view. It is the VI-VI sectional view taken on the line of FIG. 1, and its partial expanded sectional view.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  2 and 3 show a mobile phone 1 as a mobile terminal according to an embodiment of the present invention. The mobile phone 1 includes a first cabinet 3 to which a liquid crystal display unit 2 is attached, for example, on the front side. The first cabinet 3 is bonded to a second cabinet 4 as a resin molded product with a rectangular frame-shaped double-sided tape 5. The first cabinet 3 and the second cabinet 4 are both made of a substantially rectangular resin molded product that is long in the vertical direction.

  For example, the second cabinet 4 of this embodiment has a cover portion 4a as a substantially rectangular plate-shaped primary material that forms an appearance, as shown in FIG. 4 (a), and a double-sided tape 5 as shown in FIG. 4 (b). A peripheral member 4b as a secondary material having a second flat surface 4c as a rectangular frame-shaped contact surface to be attached is made of different materials. The second flat surface 4c is preferably substantially flat in order to improve the adhesiveness, adhesion, etc. of the double-sided tape 5, while the outer peripheral section of the second cabinet 4 is curved as shown in FIG. Therefore, a thick portion 12 that is thicker than other portions is formed in a part of the corresponding peripheral member 4b in appearance.

  The cover portion 4a has a rectangular plate-like primary side plate-like main body 10 having a side wall 10a around it. For example, the cover 4a has an antenna element (not shown) formed on the front side by an LDS (Laser-Direct-Structuring) method. In the LDS method, a base polymer (liquid crystal polymer resin, polybutylene terephthalate resin, etc.) is mixed into a required shape using a material that is a mixture of filler, organic metal, etc., and a laser machine is used for the molded product to form a circuit pattern. Is irradiated with laser, and plating is deposited only on the laser irradiation portion to form a circuit to be an antenna element (not shown).

  On the inner side of the side wall 10a on the left and right peripheral edges of the primary side plate-shaped body 10, a plurality of ridges 11 are provided upright so as to correspond to the thick portion 12 and project vertically from the primary side plate-shaped body 10. In the ridges 11, a plurality of pairs of ridges 11 having a predetermined interval in the width direction are arranged at predetermined intervals in the longitudinal direction, for example, at the peripheral edges on both sides in the width direction. As shown in a partially enlarged view in FIG. 5, each protrusion 11 has a longitudinal end 11 a that is gently continuous with the primary plate-like body 10. For example, the boundary between the longitudinal direction both ends 11a and the primary side plate-like body 10 is continuous in a curved shape as viewed from the width direction. It is desirable that this curve has an arc shape having a constant radius (r1, r2).

  Moreover, as shown in FIG. 5 (a), the slopes of the longitudinal ends 11a of the ridges 11 on the side farther from the gate G during the injection molding of the peripheral member 4b are closer to the gate G shown in FIG. 5 (b). The melted peripheral member 4 b is easier to flow around the ridge 11 than the slope of the ridge 11. Further, the radius r2 of the far ridge when viewed from the width direction is larger than the radius r1 of the near ridge 11 (r2> r1). Further, as shown in FIG. 6, regarding the height of the ridge 11, the height H2 on the side far from the gate G is higher than the height H1 on the near side (H2> H1). This is to prevent the secondary material surrounding the ridges 11 from being too thick in accordance with the curvature of the second cabinet 4.

  Next, a method for manufacturing the second cabinet 4 as a resin molded product according to this embodiment will be described. First, as shown in FIG. 4A, a cover portion 4a which is a primary material is formed. As described above, a material in which a filler, an organic metal, or the like is mixed with a base polymer is molded into a required shape by an injection mold, and the molded product is irradiated with laser to form a circuit serving as an antenna element.

  Next, the cover 4a is placed on another injection mold, and the peripheral member 4b, which is the secondary material shown in FIG. 4B, is insert-molded. The positions of several gates G at this time are shown in FIG.

  In the present embodiment, as shown in FIGS. 5 and 6, the thick portion 12 of the peripheral member 4 b covers the ridge 11, so that the difference in thickness between the thick portion 12 and its periphery is minimized. This can effectively prevent the occurrence of sink marks due to shrinkage during resin cooling. Moreover, since the molten resin of the peripheral member 4b flows smoothly into the circumference | surroundings of the protruding item | line 11 by making the longitudinal direction both ends 11a of the protruding item | line 11 continue to the primary side plate-shaped main body 10 gently, it is hard to generate | occur | produce a bubble and a curvature.

  Further, by arranging a plurality of ridges 11 extending in the longitudinal direction in parallel in the width direction, the thickness per one of the ridges 11 is suppressed, and the cover portion 4a which is the primary material has sink marks, warpage, etc. Can be prevented.

  Further, on the side close to the gate G, the molten resin flows easily, so even in a portion with a slight inclination, the momentum of the molten resin weakens as it moves away from the gate G. Etc. can be effectively prevented.

  Moreover, although the boundary with the primary side plate-shaped main body 10 of the longitudinal direction both ends 11a in the protruding item | line 11 was made to continue curving shape seeing from the width direction, when this injects the peripheral member 4b, it becomes a curvilinear edge part. The molten resin flows smoothly along. For this reason, sinking, warping, and the like can be more effectively prevented by making the molten resin more easily flow around the ridges 11.

  As described above, according to the present embodiment, at least one ridge 11 in which the longitudinal ends 11a are gently connected to the primary plate-like main body 10 is provided on the cover portion 4a, and at least the ridge 11 is provided on the peripheral member 4b. By providing the thick portion 12 that covers the thickness, the thickness of the substantial peripheral member 4b of the thick portion 12 is reduced, the residual stress during secondary molding is reduced, and the warp of the second cabinet 4 is prevented. Can do.

(Other embodiments)
The present invention may be configured as follows with respect to the above embodiment.

  That is, in the above-described embodiment, the primary material is the cover portion 4a having the antenna element on the surface, and the secondary material is the peripheral member 4b having the second flat surface 4c with which the double-sided tape 5 abuts. The mobile phone 1 with high merchantability can be obtained in which the capacity of the antenna can be increased and the antenna can be disposed as the next material. However, the primary material and the secondary material are not limited to this. The second flat surface 4c may be a surface with which the waterproof packing abuts, or the primary material may not be provided with an antenna element, and the use of the resin molded product is not particularly limited.

  In the above embodiment, the insert molding has been described. However, the primary material and the secondary material may be different resin materials, or the same resin material and only two-color molding different in color.

  In the above embodiment, the mobile terminal is the mobile phone 1, but it is a PHS (Personal Handy-phone System), a PDA (Personal Digital Assistant), a smartphone, a personal computer, a mobile tool, an electronic dictionary, a calculator, a game machine, and the like. Also good.

  In addition, the above embodiment is an essentially preferable illustration, Comprising: It does not intend restrict | limiting the range of this invention, its application thing, or a use. The technical features described in each embodiment can be combined with each other, and a new technical feature can be formed by combining them.

1 Mobile phone (mobile terminal)
2 Liquid crystal display
3 First cabinet
4 Second cabinet (resin molded product)
4a Cover part (primary material)
4b Peripheral member (secondary material)
4c Second flat surface (contact surface)
5 Double-sided tape
10 Primary plate body
10a side wall
11 Projections
11a Longitudinal ends
12 Thick part

Claims (5)

In a resin molded product in which a primary material made of a resin material and a secondary material made of a resin material are integrally formed by injection molding,
The primary material has a primary side plate-like main body, and at least one ridge that protrudes perpendicularly to the primary side plate-like main body and whose longitudinal ends are gently connected to the primary side plate-like main body,
The said secondary material has a thick part which covers at least the said protruding item | line, The resin molded product characterized by the above-mentioned. In the resin molded product according to claim 1,
Has a long shape on one side,
A resin molded product, wherein the plurality of ridges extending in the longitudinal direction are arranged in parallel in the width direction. In the resin molded product according to claim 2,
The slopes at both ends in the longitudinal direction of the ridges on the side far from the gate at the time of injection molding of the secondary material are gentler than the slopes of the ridges on the near side, and the molten secondary material flows into the periphery of the ridges. Resin molded product characterized by being easy. In the resin molded product according to any one of claims 1 to 3,
The resin molded product, wherein a boundary between the projecting strip and the primary side plate-like main body at both ends in the longitudinal direction is continuous in a curved shape when viewed from the width direction. In the resin molded product according to any one of claims 1 to 4,
The primary material has an antenna element on the surface,
The said secondary material has a contact surface with which a double-sided tape contacts, The resin molded product characterized by the above-mentioned.

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