JPH06340982A - Method for partially plating resin product - Google Patents

Abstract

PURPOSE:To easily and surely form a plating layer on the part of a resin product to be plated without marring the decorativeness by the formation of protrusions. CONSTITUTION:Streak grooves 11 and i8 having a V-shaped section are annularly formed on the decorative and nondecorative surface sides of an auxiliary partition plate, a truncated-conical through hole 17 is formed, and a protrusion 19 is formed on the nondecorative surface side to obtain a grill main body 2. The main body 2 is dipped in an electroless plating soln. to form an electroless plating layer 15 on the entire part except the bottoms of the grooves 11 and 18. The main body 2 is then dipped in a specified electroplating soln. plural times, a clip 28 is inserted into the protrusion 19, and a current is applied. Consequently, the electroless plating 15 formed on the part not to be plated is dissolved, the electroless plating layer 15 on the decorative surface side is electrically connected from the electroless plating layer 15 on the protrusion 19 through the through hole 17, and an electroplating layer 16 is formed on the part to be plated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for partial plating of a resin product in which a plating layer is formed only on a portion of the surface of a resin base material which requires plating.

[0002]

2. Description of the Related Art Conventionally, resin products of this type include exterior decorations such as front grilles and back panels for vehicles. For example, in the front grill, a plating layer is formed on a predetermined portion of the front surface (design surface) of the front grill, and a coating layer is formed on the other portion (however, the design surface). Thus, the front grill partially having the plating layer is manufactured, for example, as follows.

That is, first, a grill body made of ABS resin is subjected to electroless plating and electroplating. Then,
A plating layer including an electroless plating layer and an electroplating layer is formed on the entire surface of the grill body. Then, an electroforming mask is coated on the portion where the plating layer is desired to be left or the coating film is not desired to be formed, and the primer is applied to the other portions to form a primer layer. afterwards,
A predetermined coating material is applied on the primer layer to form a coating layer. Then, the front grill is obtained by removing the covering by the electroforming mask.

[0004]

However, in the above prior art, the plating layer was formed on all the surfaces of the grill body. For this reason, the plating layer is formed even in a portion where plating is unnecessary, which causes an increase in manufacturing cost.

Although the coating layer is made of a resin material, it must be formed by coating on the surface of a metal material called a plating layer. In this case, the joining between the two is a joining of different materials, so the joining force is small.
Therefore, conventionally, in order to improve the joining force between the two,
A primer was applied between the plating layer and the coating layer to form the primer layer. Therefore, the number of steps is increased by the number of steps and the cost is increased. Further, even if the primer layer is formed as described above, since the primer layer is also made of a resin material, there is still a problem in terms of bonding strength and eventually durability performance.

Further, it is conceivable to form a plating layer only on a portion requiring plating and form a coating layer on an unnecessary portion. In such a case, it is possible that all the portions that require plating become the design surface. In such cases,
In the electroplating step, it is necessary to electrically connect the portion that requires plating, but for this conduction, it is necessary to form a protrusion on the design surface side to ensure the electrical connection. Then, there is a possibility that the design may be significantly impaired by the protrusion.

The present invention has been made to solve the above-mentioned problems, and an object thereof is a resin product in which a plating layer is formed only on a portion of the surface of a resin base material which requires plating. Partial plating method for resin products, wherein the designability is not impaired by the formation of protrusions, and a plating layer can be formed easily and surely only on the part that requires plating. To provide.

[0008]

In order to achieve the above object, in the first invention, a boundary line portion between a portion requiring plating and a portion not requiring plating on the surface of a resin base material. A groove forming step of forming a groove having a substantially V-shaped cross section into an annular shape, and forming a through hole that connects the design surface side and the non-design surface side to a portion of the base material that requires plating. A through hole forming step; a projection forming step of forming a projection in a portion surrounded by a groove formed on the non-design surface side of the base material; Among the electroless plating layer formed on the base material that has undergone the electroless plating step and the electroless plating step of forming an electrolytic plating layer, the electroless plating layer formed on the protrusion is electrically conducted. And form an electroplating layer on the electroless plating layer where plating is required. And the as its gist that a electroplating process that.

In addition, the gist of the second invention is that the opening area on the design surface side of the through hole described in the first invention is smaller than the opening area on the non-design surface side.

[0010]

According to the first aspect of the present invention, in the groove forming step, a cross section is formed on the boundary line between the portion requiring plating and the portion not requiring plating on the surface of the resin base material. A substantially V-shaped groove is formed in an annular shape. Further, in the through hole forming step, a through hole that connects the design surface side and the non-design surface side is formed in a portion of the base material that requires plating, and in the protrusion forming step, the non-design surface side of the base material. A protrusion is formed in a portion surrounded by the groove formed in the. Further, in the electroless plating step, the electroless plating layer is formed on the surface of the base material other than the bottom of the groove. Then, in the electroplating step, among the electroless plating layers formed on the base material that has undergone the electroless plating step, the electroless plating layer formed on the protrusions is electrically connected to the electroless plating layer. An electroplating layer is formed on the portion where the plating is required.

Here, in the above electroless plating step, the electroless plating layer is not formed on the bottom of the groove.
Therefore, in the electroplating step, the portion requiring plating is electrically conducted to form the electroplating layer on the portion requiring plating on the electroless plating layer. Further, the electroless plating layer in the portion where plating is unnecessary is removed. further,
During the electroplating step, the electroless plating layer formed on the projections in the portion surrounded by the groove formed on the non-designed surface side of the base material is electrically conducted. Therefore, the electroless plating layer on the design surface side is electrically conducted from the electroless plating layer on the portion through the electroless plating layer on the through hole portion. Therefore,
Even if the protrusion is not formed on the design surface side, electrical conduction is performed from the non-design surface side, and the electroplating layer is formed on a portion of the electroless plating layer where plating is required. Therefore, the deterioration of the appearance quality due to the formation of the projection on the design surface side is suppressed.

In addition, according to the second invention, the opening area on the design surface side of the through hole of the first invention is smaller than the opening area on the non-design surface surface. Therefore, even if the opening area on the design surface side is made as small as possible, it is possible to surely form the electroless plating layer in the through-hole portion, and it is possible to reliably form the non-design surface side to the design surface side. Electrical conduction can be performed. Therefore, although a through hole is formed on the design surface side as a result, if the through hole is small, it is difficult to be recognized from the outside.

[0013]

【Example】

(First Embodiment) A first embodiment in which the present invention is embodied in a vehicle front grill 1 as a resin product will be described below with reference to FIGS. 1 to 9. However, the following drawings may have some schematic parts for easy understanding of the invention.

A front grill 1 as shown in FIG. 1 is mounted on the front surface of the vehicle. Figures 1, 2,
As shown in FIG. 9, the front grill 1 includes a front grill body (hereinafter referred to as a grill body) 2 as a base material made of ABS resin, and a part of its design surface, that is, a part of the front surface. The formed plating layer 3 (Fig. 2
Has a mesh-like portion) and a coating layer 4 applied and formed on a portion other than the plating layer 3 (excluding a part on the back side). More specifically, the front grill 1
Is a frame 5 having a substantially rectangular front shape, a plurality of sub-partition plates 6 extending in the horizontal direction within the frame 5, a plurality of connecting plates 7 extending in the vertical direction within the frame 5, and a mark plate (not shown) in the central portion. Mounting plate 8 and frame 5 for mounting
It has a main partition plate 9 and the like extending from to the mounting plate 8. Then, mainly the front side portion of the frame 5,
The plating layer 3 is formed on the front side portions of the main partition plate 9 and the sub partition plate 6. In addition, the coating layer 4 is mainly formed on the front side portion of the mounting plate 8 and the connecting plate 7.
Are formed.

Here, the description of the method of forming the plating layer 3 mainly on the front side portion of the frame 5 and on the front side portion of the main partition plate 9 will be omitted. In this embodiment, a method of partially plating the island-shaped partial plating, that is, the partial partition plate 6, will be described in detail below.

FIG. 3 is an enlarged front view showing a part (γ portion in FIG. 2) of the sub partition plate 6, and FIG. 4 is an XX line in FIG.
It is a line sectional view. As shown in these figures and FIG. 9, on the front side (design surface side) of the grill body 2, at the boundary between the plating layer 3 and the coating layer 4, the frame 5 and the sub-partition plate 6 are vertically moved. The step portion 10 protruding in the direction is formed in an annular shape. The step portion 10 is formed with a groove 11 having a substantially V-shaped cross section in an annular shape (closed curved shape). The inside of the sub-partition plate 6 is hollow so that the rear surface side (non-design surface side) is open.

As shown in FIG. 9, the plating layer 3 comprises an electroless plating layer 15 and an electroplating layer 16. In this embodiment, the electroless plating layer 15 is made of nickel and has a thickness of about 0.3 to 0.4 μm. Further, the electroplating layer 16 is formed of three kinds of metals such as copper, nickel and chromium to a thickness of about 20 to 50 μm, and has a multi-layer structure.

The width of the groove 11 is "0.5 mm" and the depth D1 thereof is "0.5 mm". However, the width W1 is not particularly limited, but is preferably "0.2 mm" or more in view of processing restrictions,
It is preferably "1.0 mm" or less in order to improve the design. The depth D1 is also not particularly limited, but is preferably "0.2 mm" or more due to the processing limitation, and "0.6 mm" due to the restriction on the strength of the grill body 2.
mm "or less is preferable. Further, the depth D1 with respect to the width W1
The ratio (D1 / W1) is preferably "1.0" or more.

Further, in this embodiment, the sub partition plate 6
A through hole 17 is formed in a truncated cone shape in the step portion 10 projecting downward. In the stage of the grill body 2, the through hole 17 has a diameter of 0.3 m at the opening on the design surface side.
The diameter of the portion opened toward the non-design surface is formed to be about “3 mm”.

In addition, in this embodiment, the sub partition plate 6 is also used.
On the non-design surface side of the grill body 2 portion, a groove groove 18 having a substantially V-shaped cross section is formed in an annular shape (circular shape) so as to surround the through hole 17.

In addition, in this embodiment, the groove 18
A protrusion 19 is integrally formed near the through hole 17 in a portion surrounded by the arrow so as to protrude to the back surface side.

Next, the mold 21 for molding the grill body 2 will be described. As shown in FIG. 5, the mold 21 includes a fixed mold 22 and a movable mold 23. A cavity 24 for molding the grill body 2 is formed by these two molds 22 and 23. However, the fixed mold 22 is integrally formed with a truncated cone-shaped projection 25 for forming the through hole 17, and is integrally formed with a projection 26A for forming the groove 18. There is.
Further, the movable die 23 is integrally formed with a protrusion 26B for forming the groove 11. Further, the fixed mold 22 is provided with a hole 27 for forming the protrusion 19.

Next, the operation and effect of manufacturing the front grill 1 will be described. However,
Here, as described above, the partial plating method for the sub partition plate 6 will be mainly described.

First, the melted ABS resin is injected and filled in the cavity 24 by a known die molding method (see FIG. 5). Once the resin has cooled and solidified,
Both molds 22 and 23 are opened, and the grill main body 2 is taken out. At this time, the two molds 22 and 23 are opened in parallel with the mold opening direction, that is, in the direction in which the protrusions 25, 26A, 26B and the like are removed. Therefore, the mold opening is not hindered by the protrusions 25, 26A, 26B and the like, and the grill body 22 can be easily taken out. In this way, the grill main body 2 in which the grooved grooves 11 and 18 are formed in a predetermined shape in an annular shape is obtained.

Subsequently, the grill body 2 is immersed in an electroless plating solution to perform electroless plating. At this time, as shown in FIG. 6, the plating solution does not reach the bottoms 11a and 18a of the grooves 11 and 18 because the gaps are narrow. Therefore, the bottoms 11a and 18a are not plated. In other words, the bottom part 1 on the surface of the grill body 2
The electroless plating layer 15 is formed on all portions except 1a and 18a.

Next, as shown in FIG. 7, the grill main body 2 on which the electroless plating layer 15 is formed is subjected to electroplating.
That is, the main body 2 is dipped in a predetermined electroplating solution a plurality of times, and a portion requiring plating (a front side portion of the sub partition plate 6) is electrically connected. That is, as shown in the figure, with respect to the electroless plating layer 15 formed on the protrusion 19 protruding to the non-design surface side of the grill body 2,
Insert the clip 28. Then, an electric current is applied to the clip 28. Then, the electroless plating layer 15 (on the outer peripheral sides of the grooves 11 and 18) formed in the portion that does not require plating is dissolved by the electroplating solution. Further, the electroplating layer 16 having the above-described multilayer structure is formed on the surface of the electroless plating layer 15 in the portion requiring plating. That is, through the electroless plating layer 15 formed on the protrusion 19 through the electroless plating layer 15 formed on the through hole 17 portion, the non-electroplating layer formed on the design surface side and the inner peripheral side of the groove 11 is formed. A current flows through the electroplated layer 15, and the electroplated layer 16 is formed in that portion. In this way, the grill body 2 in which the electroless plating layer 15 and the electroplating layer 16 (plating layer 3) are formed is formed only in the portion that requires plating.

After that, as shown in FIG. 8, the portion where the plating layer 3 is formed is covered with an electroforming mask 29. That is, the electroformed mask 29 is a metal plate having a thickness of “several mm” and has a shape conforming to the shape of the front grill 1. In addition, the electrocast mask 29 is open only in a portion necessary for forming the coating layer 4. By the coating of the electroformed mask 29, a portion necessary for forming the coating layer 4 is exposed. Then, as shown in FIG. 9, spray coating is applied toward the exposed portion. By this coating, the coating film layer 4 is formed on the required portions of the coating film. On the other hand, the coating film layer 4 is not formed on the portion covered with the electroforming mask 29.

After the coating layer 4 is formed, the electrocast mask 29 is uncovered to obtain the front grill 1 described above. That is, the front grill 1 having the plating layer 3 substantially on the front side of the sub partition plate 6 and the coating layer 4 on the outer peripheral portion thereof can be obtained.

As described above, according to this embodiment,
When forming the electroless plating layer 15 described above, the groove 1
The electroless plating layer 1 is formed on the bottom portions 11a and 18a of the electrodes 1 and 18.
5 is not formed. Therefore, when the electroplating layer 16 is formed, only the portion requiring plating is electrically conducted. That is, the electroless plating layer 15 formed in the portion that does not require plating is dissolved by the electroplating solution. Further, the electroplating layer 16 having the above-described multilayer structure is formed on the surface of the electroless plating layer 15 in the portion requiring plating. for that reason,
At this stage, the grill main body 2 in which the plating layer 3 is surely formed only in the necessary portion can be obtained. Therefore, when forming the coating layer 4, it is possible to directly form the coating layer 4 on the grill main body 2 without interposing the primer layer.

As a result, the step of forming the primer layer is not required, so that the number of working steps and the cost can be reduced. Further, since it is not necessary to form the electroplating layer 16 on the entire surface of the grill body 2, the cost can be reduced accordingly.

Further, in the front grill 1, the coating layer 4 is directly formed on the grill main body 2. Therefore, the thickness of the portion is reduced by the amount that the plating layer 3 and the primer layer are not interposed. As a result, the thickness of the coating film layer 4 portion can be reduced, and the appearance quality can be improved. Furthermore, since the coating layer 4 and the grill body 2 are both made of a resin material,
The coating layer 4 can be firmly bonded to the grill body 2. Therefore, the durability of the coating layer 4 of the front grill 1 can be improved.

In addition, in this embodiment, the groove 11 on the front side serves as the boundary between the coating layer 4 and the plating layer 3. For this reason, the parting portion of the boundary portion is clearly formed instead of the zigzag shape. As a result, the parting line can be made clear and clear, and further, the appearance quality can be further improved.

In addition, in the electroplating step, which is a characteristic part of the present invention, in this embodiment, there is no protrusion 19 formed on the portion surrounded by the groove 18 formed on the non-design surface side of the grill body 2. The electrolytic plating layer 15 is electrically conducted. Therefore, the electroless plating layer 15 on the design surface side is electrically conducted from the electroless plating layer 15 on the portion through the electroless plating layer 15 on the through hole 17. Therefore, even if a protrusion is not separately formed on the design surface side, electrical conduction is performed from the non-design surface side, and the electroplating layer 16 is formed on a portion of the electroless plating layer 15 where plating is required. Therefore, it is possible to suppress the deterioration of the appearance quality due to the formation of the protrusion, and it is possible to improve the design.

In addition, according to this embodiment, the through hole 17
In, the opening area on the design surface side is smaller than the opening area on the non-design surface side. Therefore, even if the opening area on the design surface side is made as small as possible, the electroless plating layer 15 can be reliably formed in the through hole 17 portion, and the non-design surface side to the design surface side can be formed. Reliable electrical continuity can be achieved. Therefore, although the through hole 17 is formed on the design surface side as a result, it becomes difficult to be recognized from the outside by sufficiently reducing the opening area of the through hole 17 on the design surface side. As a result, it is possible to further improve the design.

In addition, in this embodiment, the through hole 17 is formed in the grill body 2 and the groove 18 is formed on the non-design surface side. Therefore, the plating layer 3 formed on the non-designed surface side only needs to be a portion surrounded by the groove 18. Therefore, the amount of the plating solution used as a whole can be reduced, and the cost can be reduced.

(Second Embodiment) Next, a second embodiment in which the present invention is embodied in a vehicle back panel 51 as a resin product will be described with reference to FIGS. However, also in this embodiment, since the main part of the invention is almost the same as that of the above-described first embodiment, the difference will be mainly described.

A back panel 5 as shown in FIG. 10 is provided on the rear portion of the vehicle where the license plate is mounted.
1 is attached. The back panel 51 is formed in a substantially box shape having an opening partly. Back panel 51
Is a back panel main body 52 as a base material made of ABS resin.
(See FIG. 11), and a plating layer 53 formed in a substantially rectangular shape on a part (top) of the design surface and an inner peripheral surface other than the plating layer 53 (excluding the non-design surface). The coating film layer 54 is formed by coating. A red transparent decoration member 55 extending in the lateral direction is attached to the upper portion of the back panel body 52.

As shown in FIGS. 12 and 13, in the back panel main body 52, the plating layers 5 on the inner and outer peripheral sides are formed.
An inner peripheral side stepped portion 56 and an outer peripheral side stepped portion 57 are formed in an annular shape at the boundary between the coating layer 54 and the coating layer 54.
The stepped portions 56 and 57 are formed with annular grooves 58, 59 and 64 having a substantially V-shaped cross section in an annular shape (closed curve shape). A through hole 63 is formed in the portion covered with the decorative member 55. Further, on the back side of the portion covered with the decorative member 55, the non-design surface side direction,
That is, the electrode projection 60 that projects toward the front of the vehicle is formed (see FIG. 11). In addition, a groove 64 is formed in an annular shape on the back side of the portion covered with the decorating member 55 so as to surround the through hole 63 and the electrode projection 60. By this groove 64, the conduction of plating to the outside is blocked.

In addition, the plating layer 53 has an electroless plating layer 61 and an electroplating layer 62 formed thereon, as in the above embodiment. The back panel 51 is manufactured in the same manner as in the above embodiment. That is, electroless plating is applied to the back panel main body 52 in which the grooves 58 and 59 are formed annularly at predetermined locations. Then, the bottom portions 58a and 59a of the groove 58 and 59 are formed.
In, the plating solution does not reach because the gap is narrow. Therefore, the bottoms 58a and 59a are not plated, and the electroless plating layer 61 is formed on all parts except the bottoms 58a and 59a. Then, the back panel body 52 on which the electroless plating layer 61 is formed is subjected to electroplating. At this time, similarly to the above-described embodiment, the electrode projection 60 formed on the back panel main body 52 is formed as one electrode. Then, the electroless plating layer 61 formed on the portion not requiring plating (inner peripheral surface or the like) is dissolved by the electroplating solution. Further, the electroplating layer 62 having the above-described multilayer structure is formed on the surface of the electroless plating layer 61 at the portion (top portion) that requires plating. In this way, the back panel body 52 in which the electroless plating layer 61 and the electroplating layer 62 (plating layer 53) are formed is formed only in the portion requiring plating.

After that, as in both the above-described embodiments, the portion where the plating layer 53 is formed is covered with an electroforming mask (not shown). Then, spray coating is applied to the exposed portion. By this coating, the coating film layer 54 is formed in the required portions of the coating film. After the coating layer 54 is formed, the coating of the electroforming mask is released to obtain the back panel 51. That is, the back panel 51 having the plating layer 53 on the top and the coating layer 54 on the inner peripheral surface is obtained. Also, in this embodiment, the same operation and effect as those of the first embodiment can be obtained.

Also in this embodiment, the electrode projection 6 is used.
Since 0 is formed on the non-design surface side, the projection 60 does not impair the design. Further, the plating layer 53 formed on the non-designed surface side only needs to be a portion surrounded by the groove 64. Therefore, the amount of the plating solution used as a whole can be reduced, and the cost can be reduced.

The present invention is not limited to the above-described embodiments, but can be implemented as follows with a part of the configuration appropriately changed without departing from the spirit of the invention. (1) In the first embodiment, the present invention is embodied in the front grille 1 for a vehicle, and in the second embodiment is embodied in the back panel 51 for a vehicle. Pillar garnish for vehicle, quarter vent for vehicle, mark plate for vehicle, outer cover for door mirror bracket for vehicle, and the like. Further, the present invention is not limited to the above resin products, and the present invention may be embodied in other resin products partially having a plating layer.

(2) In each of the above embodiments, the resin material constituting the base material is made of ABS resin. However, in addition to this, for example, polypropylene, polyphenylene oxide, polyamide, polysulfone, polyester, etc. Various resin materials may be used.

(3) In each of the above embodiments, the electroless plating layers 15 and 61 are made of nickel, but they may be made of copper or the like in addition to them. Further, in the above-mentioned embodiment, the electroplating layers 16 and 62 are formed of three kinds of metals of copper, nickel and chromium so as to form a multi-layer structure, but metals other than these may be used. It may be embodied when not having a multilayer structure.

(4) In each of the above-described embodiments, the die 21 is used to form the grooves 11, 18, 58, 59, but each groove is post-processed by an NC cutter, an ultrasonic cutter or the like. You may form by.

(5) In the first embodiment, the through hole 17 is embodied in the case where the through hole 17 is formed in the vicinity of the central portion in the height direction of the sub partition plate 6, but in the case where it is formed in the step portion 10 protruding downward. May be embodied in. In such a case, the front grill 1
Since the through hole 17 is located at a position that is difficult to be recognized from the outside during use, it is possible to further suppress the deterioration of the appearance quality.

(6) In each of the above embodiments, the coating layer may not be formed.

[0048]

As described above in detail, in the present invention,
According to the partial plating method of the resin product, in the resin product in which the plating layer is formed only on the portion requiring the plating on the surface of the resin base material, the designability is not impaired by the formation of the protrusions, Moreover, there is an excellent effect that the plating layer can be easily and surely formed only in the portion where the plating is required.

[Brief description of drawings]

FIG. 1 is a front view showing a front grille according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a plated portion of the front grille in the first embodiment, and is a schematic diagram in which the front grille is developed on the front surface and the back surface.

FIG. 3 is a front view showing, in an enlarged manner, a part of a sub partition plate of the front grille in the first embodiment.

FIG. 4 is a sectional view taken along line XX of FIG. 3 in the first embodiment.

FIG. 5 is a cross-sectional view showing, in an enlarged manner, a part of a mold for molding the grill body in the first embodiment.

FIG. 6 is a partial cross-sectional view showing a state in which electroless plating is applied to the grill body in the first embodiment.

FIG. 7 is a partial cross-sectional view showing a state in which electroplating has been applied to the grill body on which the electroless plating layer is formed in the first embodiment.

FIG. 8 is a partial cross-sectional view showing a state in which the electroformed mask is coated on the portion of the grill body where the plating layer is formed in the first embodiment.

FIG. 9 is a sectional view showing a main part of a sub partition plate of the front grill in the first embodiment.

FIG. 10 is a front view showing a back panel according to a second embodiment of the present invention.

FIG. 11 is a side sectional view showing a back panel body in the second embodiment.

FIG. 12 is a partial perspective view showing a plated top portion and the like of the back panel body in the second embodiment.

13 is a sectional view taken along line CC of FIG. 10 in the second embodiment.

[Explanation of symbols]

2 ... Grill main body as base material, 3, 53 ... Plating layer,
4, 54 ... Coating layer, 11, 18, 58, 59, 64 ... Grooves, 11a, 18a, 58a, 59a ... Bottom portion, 15, 6
1 ... Electroless plating layer, 16, 62 ... Electroplating layer, 1
7, 63 ... Through holes, 19, 60 ... Protrusions, 52 ... Back panel body as a base material.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Naruyuki Takahashi No. 1 Nagahata, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Toyoda Gosei Co., Ltd. Address: Toyoda Gosei Co., Ltd.

Claims (2)

[Claims] 1. A groove (11) having a substantially V-shaped cross section at a boundary portion between a portion requiring plating and a portion not requiring plating on the surface of a resin base material (2, 52). , 1
8, 58, 59, 64) forming a groove in an annular shape, and a through hole that connects the design surface side and the non-design surface side to the portion of the base material (2, 52) that requires plating. A through hole forming step of forming (17, 63), and a projection (19, 60) at a portion surrounded by a groove (18, 64) formed on the non-design surface side of the base material (2, 52). A step of forming a protrusion, and the groove (11, 18, 5) on the surface of the substrate (2, 52).
8, 59, 64) bottom (11a, 18a, 58a, 5)
9a), an electroless plating step of forming an electroless plating layer (15, 61), and the electroless plating layer (15) formed on the base material (2, 52) after the electroless plating step. , 61), the electroless plating layer (15, 61) formed on the protrusion (19, 60) is electrically conducted to require plating on the electroless plating layer (15, 61). An electroplating step of forming an electroplating layer (16, 62) on a certain portion of the resin product. 2. The partial plating method for a resin product according to claim 1, wherein the opening area of the through hole (17) on the design surface side is smaller than the opening area on the non-design surface side.