JP4498799B2 - In-mold coating mold - Google Patents

Description

The present invention relates to a translucent display body such as a vehicle interior switch or an audio cover, or a vehicle exterior back panel in which characters, symbols, patterns, etc. are displayed by illuminating light from behind . The present invention relates to a mold for in-mold coating molding used for manufacturing .

  In general, a primary resin layer having a light transmitting portion in which characters or symbols protrude from the design surface of a translucent base material is molded, and then a light-shielding paint is formed so as to avoid the tip surface of the light transmitting portion. There is known a method for manufacturing a translucent display body, in which the layer is integrated on the design surface of the primary resin layer. However, when the characters to be displayed on the design surface are alphabet letters “A”, “O”, etc., that is, when there is an isolated light shielding portion (inner light shielding portion) surrounded by the light transmitting portion on the design surface, the light transmission It is necessary to fill the paint so as to bridge the light transmission part from the outer light shielding part arranged around the part to the inner light shielding part.

  For example, in the translucent display shown in Patent Document 1, a protruding piece is provided behind the light transmitting portion, and a bridge portion is formed along the outer peripheral surface of the protruding piece. It bridges the shading part. In the manufacture of the translucent display body, a movable mold having a core mold which is used to mold the protruding piece and is movable is used. At the time of manufacture, after the projecting piece is formed, the core mold is first moved with respect to the movable mold, and a communication path is formed between the projecting piece and the core mold so as to communicate the outer light shielding portion and the inner light shielding portion. Thereafter, the paint is filled from the outer light-shielding portion to the inner light-shielding portion through this communication path. And the bridge part is shape | molded linearly along the outer peripheral surface of a protrusion piece, when the coating material with which this communicating path was solidified.

And, conventionally, a projecting piece is provided behind the light transmitting part, and the core part for forming the bridge part is moved backward so that the bridge part is formed along the outer peripheral surface of the projecting piece, There is known a translucent display configured such that light from the back reaches a light transmission portion from both side surfaces of the protruding piece (see, for example, Patent Document 1).
JP-A-2-228691

  However, in the translucent display body in which the bridge portion as described above is formed, when the light is irradiated from behind, the shadow by the bridge portion is likely to be reflected on the light transmissive portion, and the design property is likely to be deteriorated. Moreover, in the translucent display body shown in Patent Document 1, there is a problem in the sealing performance between the metal core mold and the metal movable mold, and when the core mold is moved after the protruding piece is formed, The paint is likely to leak from the gap between the core mold and the movable mold, which may cause molding defects.

The present invention has been made paying attention to such problems existing in the prior art. The object is to manufacture a light-transmitting display body that can reduce molding defects while suppressing deterioration in design properties even if it has a light-shielding portion surrounded by the inside of the light-transmitting portion. Another object of the present invention is to provide a mold for in-mold coating molding used in the above.

In order to achieve the above object, the invention described in claim 1 is based on a base material made of a resin having a light transmitting property and a paint having a light shielding property formed so as to cover the surface of the base material in layers. The design surface has a light transmissive part, an inner light shielding part surrounded by the light transmissive part, and an outer light shielding part arranged outside the light transmissive part, The light transmitting portion is formed from a convex portion formed on the surface of the base material, the inner light shielding portion and the outer light shielding portion are formed from the surface material, and a bridge groove is provided in the back surface of the base material, A mold for in-mold coating molding used for manufacturing a translucent display body in which a bridge part is formed in a bridge groove, and the inner light-shielding part and the outer light-shielding part are connected by the bridge part on the back surface of the base material. A first mold, a second mold, and a third mold, the base is molded by the first mold and the second mold, The surface material is formed on the surface of the base material by the first mold and the third mold, and a core mold for forming the bridge groove protrudes from the cavity surface of the first mold. The core mold is configured to be movable back into the first mold so that the bridge portion is formed, and the core mold in a state of being moved backward is in contact with the inner surface of the bridge groove; and The gist of the invention is that the front end surface is located on the design surface side of the back surface of the base material forming the bridge groove, and the side surface of the core mold has a tapered shape that becomes narrower toward the backward movement direction .

  According to the above configuration, since the side surface of the core mold in the retreated state is in contact with the inner surface of the bridge groove, the periphery of the core mold can be sealed by the base material, and the sealing performance is improved. Molding defects are unlikely to occur. In addition, since the bridge part is formed thinner than the thickness of the base material, the shadow of the bridge part reflected in the light transmission part becomes thin when light is irradiated from behind, and the design of the translucent display body is improved. To do.

Further , the side surface of the core mold has a tapered shape that becomes narrower in the backward movement direction. For this reason, even when the core mold is moved backward when the bridge portion is formed, the adhesion between the side surface of the core mold and the base material is increased, and it is possible to prevent the paint from leaking between them. it can. Therefore, it becomes easy to reduce molding defects due to paint leakage of the translucent display body.

According to the present invention, even in the case of having a light-shielding portion surrounded by the inside of a light-transmitting portion, it is possible to manufacture a light-transmitting display body capable of reducing molding defects while suppressing a decrease in designability. A mold for in-mold coating molding to be used can be provided.

Hereinafter, an embodiment in which the present invention is embodied in a vehicle interior switch will be described with reference to FIGS.
As shown in FIGS. 1 to 3, the pressing member 11 as a light-transmitting display body of this embodiment includes a base material 12 and a surface formed on the surface of the base material 12 so as to cover the surface in layers. It has a material 13 and has a covered square tube shape having an upper wall 14 and a side wall 15. The base material 12 is formed in the shape of a covered square cylinder from a resin having optical transparency. A convex portion 12a is formed on the upper surface of the base material 12 so as to represent a predetermined character or the like (in this embodiment, alphabet “A”). Here, the “light-transmitting resin” includes any resin that can transmit light regardless of whether it is colored or colorless, transparent or translucent, and is preferably made of a white resin. Examples of this resin include acrylic resin, polycarbonate resin, and urethane resin.

  The surface material 13 is made of a liquid thermosetting paint having a light shielding property, and is formed so as to cover the surface of the base material 12 other than the convex portions 12a. Here, “having light shielding properties” means a state of being colored to the extent that light cannot be transmitted. The surface material 13 is formed to be thinner than the base material 12. The thickness of the surface material 13 is preferably 20 μm or more and 300 μm or less, and more preferably 50 μm or more and 200 μm or less. When the thickness of the surface material 13 is less than 20 μm, it is difficult to form a uniform and smooth film. When the thickness is larger than 300 μm, the pressing member 11 is not suitable for downsizing. In addition, the increase in the thickness induces a decrease in the amount of transmitted light, resulting in a pressing member with low brightness.

  An upper surface of the pressing member 11 is a design surface 11a. In the design surface 11a, the tip surface of the convex portion 12a constitutes a light transmission portion 12b. Moreover, in the design surface 11a, the surface of the surface material 13 constitutes a light shielding portion. This light shielding portion is composed of an outer light shielding portion 13c and an inner light shielding portion 13b. That is, the light transmission part 12b is based on the shape of the convex part 12a and has an annular part (a triangular part in "A"), and is surrounded by the inside of the annular part of the light transmission part 12b. The part where the light is shielded is the inner light-shielding part 13b, and the other part is the outer light-shielding part 13c.

  As shown in FIG.2 and FIG.3, the bridge groove 12c is formed in the back surface of the base material 12 which forms the cyclic | annular convex part 12a. That is, the bridge groove 12c is opened on the back surface of the base material 12 that forms the convex portion 12a. A linear bridge portion 13d made of the paint is provided inside the bridge groove 12c, and the inner light-shielding portion 13b and the outer light-shielding portion 13c are connected by the bridge portion 13d. The bridge portion 13d is located closer to the design surface 11a than the opening of the bridge groove 12c, in other words, the back surface of the base material 12 forming the bridge groove 12c.

  Accordingly, when the pressing member 11 irradiates light from behind (below), the inner light shielding portion 13b and the outer light shielding portion 13c block light, and only the light transmitting portion transmits light. Is displayed on the design surface 11a in a shining manner.

Next, the manufacturing method of the said pressing member 11 is demonstrated based on FIGS.
First, the 1st metal mold | die 20 and the 2nd metal mold | die 21 as a metal mold | die for in-mold coating molding for manufacturing the said press member 11 are demonstrated.

  As shown in FIGS. 4 (a) and 4 (b), the first mold 20 for molding the substrate 12 is composed of a first mold 22 and a second mold 23, and is clamped in the vertical direction. As a result, the first cavity 24 is formed. The second mold 21 for molding the surface material 13 on the surface of the substrate 12 is obtained by replacing the second mold 23 with a third mold 25, that is, the first mold 22 and the third mold 25. It consists of and. The second mold 21 is configured such that a second cavity 26 is formed between the surface of the substrate 12 and the third mold 25 by clamping the mold in the vertical direction. On the cavity surface of the first mold 22, a columnar core mold 22 a for forming the bridge portion 13 d is projected. The core mold 22 a extends in the vertical direction from the first mold 22 and is configured to be able to move backward in the first mold 22.

  As shown in FIGS. 5A and 5B, a protrusion 22b is provided at the tip of the core mold 22a. The side surface of the protrusion 22b has a tapered shape that becomes narrower toward the first mold 22. This ridge 22b forms the bridge groove 12c and the bridge portion 13d. Further, in a state where the core mold 22a is moved back into the first mold 22, the protrusion 22b is not withdrawn from the bridge groove 12c, and the tip surface 22c of the protrusion 22b (tip surface of the core mold 22a). Is positioned closer to the design surface 11a than the opening of the bridge groove 12c.

  Now, as shown in FIGS. 4A and 4B and FIGS. 5A and 5B, a first cavity 24 formed by the first mold 22 and the second mold 23 is inserted into a gate (not shown). The base material 12 having the convex portions 12a on the surface is formed by filling and solidifying the resin having light transmittance. Thereafter, the second mold 23 is moved upward to open the first mold 20, and the second mold 23 is replaced with the third mold 25. At this time, the side surface 12e of the base material 12 extends in parallel with the direction in which the second mold 23 opens.

  Next, the first mold 22 and the third mold 25 are clamped in a state where the base 12 molded as described above is placed on the first mold 22, and the tip of the convex portion 12a of the base 12 is clamped. The surface and the cavity surface 25a of the third mold 25 are brought into close contact with each other. As a result, a second cavity 26 is formed between the surface of the substrate 12 and the cavity surface 25 a of the third mold 25. Then, as shown in FIGS. 6A and 6B, the core mold 22 a is moved backward within a range in which the tip surface 22 c of the protrusion 22 b is located on the design surface 11 a side with respect to the back surface of the substrate 12. . Then, in the bridge groove 12c, a communication path 27 that communicates the inside and the outside of the convex portion 12a of the base 12 is surrounded by the inner surface of the bridge groove 12c and the tip surface 22c of the protrusion 22b. Formed. At this time, by making the side surface of the ridge 22b into a tapered shape, the ridge 22b contacts and bites into the inner surface of the bridge groove 12c, and the side surface of the ridge 22b and the inner surface of the bridge groove 12c The tightness between them is increased.

  Subsequently, the liquid thermosetting paint having the light shielding property is caused to flow into the second cavity 26 from a gate (not shown). At this time, the inflow direction of the paint in the second cavity 26 is the same as the direction in which the communication path 27 extends. As a result, the paint is less likely to be applied with a force in a direction to leak from the communication path 27, and is quickly supplied to the inside of the convex portion 12 a of the base material 12 through the communication path 27. Then, after the second cavity 26 is completely filled with the paint, the paint is cured to form the surface material 13 on the surface of the substrate 12. At this time, the bridge portion 13d is formed by the paint in the communication passage 27.

  Here, the thickness of the second cavity 26 is preferably 20 μm or more and 300 μm or less, and more preferably 50 μm or more and 200 μm or less. Further, the liquid thermosetting paint preferably has a viscosity of 3 Pa · s to 100 Pa · s at 25 degrees Celsius, more preferably 30 Pa · s to 50 Pa · s. . When the viscosity of the liquid thermosetting paint at 25 degrees Celsius is less than 3 Pa · s, the liquid thermosetting paint enters the seam between the first mold 22 and the third mold 25 to generate burrs. There is a fear. Further, when the viscosity of the liquid thermosetting paint at 25 degrees Celsius is greater than 100 Pa · s, the liquid thermosetting paint may not sufficiently flow into every corner of the second cavity 26.

  Therefore, the liquid thermosetting paint can be sufficiently poured into every corner even in the second cavity 26 having a very thin thickness as described above. At this time, the front end surface of the convex portion 12a of the substrate 12 and the cavity surface 25a of the third mold 25 are in close contact with each other, so that the surface material 13 is not formed on the front end surface.

After the pressing member 11 is formed, the third mold 25 is opened upward, and then the pressing member 11 is taken out from the second mold 21.
According to the embodiment detailed above, the following effects are exhibited.

  The bridge portion 13d that connects the inner light-shielding portion 13b and the outer light-shielding portion 13c is configured to be accommodated in the bridge groove 12c that is recessed in the back surface of the base member 12, and thus the bridge groove 12c is provided. In this case, the thickness of the bridge portion 13d is thinner than that of the inner light shielding portion 13b and the outer light shielding portion 13c, and the width dimension of the bridge portion 13d can be reduced. Moreover, the convex part 12a is also thin compared with another location. For this reason, when light is irradiated from behind in the portion, the light is easily transmitted, and the shadow of the bridge portion 13d reflected in the light transmission portion 12b becomes thin, and the design of the pressing member 11 is improved. In addition, when the pressing member 11 is molded, the paint that becomes the bridge portion 13d is less likely to leak out of the bridge groove 12c, and molding defects can be reduced.

  The side surface of the ridge 22b has a tapered shape that becomes narrower in the backward movement direction. For this reason, when the pressing member 11 is formed, the protrusion 22b in the retracted state has its side surface in contact with the inner surface of the bridge groove 12c and bites into the protrusion 22b, so that the peripheral edge of the protrusion 22b is reliably secured by the base material 12. Sealed. Therefore, it is possible to suppress the paint from leaking between the protrusion 22b and the base material 12, and molding defects are less likely to occur. Further, since the bridge portion 13d is formed thinner than the thickness of the base material 12, the shadow of the bridge portion 13d reflected on the light transmission portion 12b becomes thin when light is irradiated from behind, and the design of the pressing member 11 is reduced. Improves.

  -Since the 2nd cavity 26 is 20 micrometers or more and a thickness of 300 micrometers or less, it becomes easy to make thickness of the surface material 13 which comprises the said design surface 11a thin. For this reason, the pressing member 11 can be made compact. In addition, since the pressing member 11 does not become thick, the operability of the pressing member 11 can be improved.

-Since the front-end | tip surface of the convex part 12a of the base material 12 and the surface of the surface material 13 are the same, an unevenness | corrugation does not arise in the design surface 11a. For this reason, the designability of the design surface 11a can be improved.
The side surface 12e of the substrate 12 is parallel to the direction in which the first and third molds 22 and 25 open, so that the cross section of the design surface 11a is U-shaped, that is, the design surface 11a is at right angles. Even if it is bent, the light shielding part can be easily formed on the design surface 11a. Therefore, it is convenient for molding a vehicle interior switch or an audio cover having a design surface bent at a right angle. Further, in the molding method for exchanging the second mold 23 and the third mold 25, the thickness of the surface material 13 formed on the surface of the side surface 12 e of the base 12 is formed on the upper surface of the base 12. It is easy to make it the same as the thickness of the surface material 13.

-Since the said liquid thermosetting type paint has adhesiveness, the peeling resistance of the surface material 13 with respect to the base material 12 can be improved.
The viscosity of the liquid thermosetting paint is 3 Pa · s or more and 100 Pa · s or less at 25 degrees Celsius, so even if the second cavity 26 is very narrow (thickness is 20 μm or more and 300 μm or less), the second cavity 26 Since the liquid thermosetting paint penetrates every corner, it becomes easy to significantly reduce the thickness of the surface material 13 as compared with the case of using a thermoplastic resin. For this reason, the pressing member 11 can be formed compactly.

(Example of change)
In addition, the said embodiment can also be changed and actualized as follows.
As shown in FIGS. 7A and 7B, the tip surface 42c of the protrusion 42b at the tip of the core mold 42a is recessed in a U-shaped cross section. Then, as shown in FIGS. 8A and 8B, the core mold 42a is moved backward within a range in which the tip surface 42c of the ridge 42b is located closer to the design surface 31a than the opening of the bridge groove 32c. Thereafter, the second cavity 46 is filled with a liquid thermosetting paint and cured to form the surface material 33 on the surface of the substrate 32. At this time, the bridge portion 33 d is formed by the paint in the communication passage 47.

  In this way, since the bridge portion 33d is formed in the middle of the base material 32, the convexity of the base material 32 between the bridge portion 33d and the design surface 31a can be achieved without increasing the thickness of the base material 32. The thickness of the part 32a can be increased. Accordingly, the difference between the thickness of the bridge portion 33d and the thickness of the convex portion 32a is increased, and when the light is irradiated from behind the pressing member 11, the shadow of the bridge portion 33d reflected on the light transmission portion 32b is further reduced. The design property of the pressing member 11 is improved.

  As shown in FIGS. 9 (a) and 9 (b), the tip surface 62c of the protrusion 62b at the tip of the core mold 62a has a U-shaped section larger than that shown in FIGS. 7 (a) and 7 (b). It is set as the structure dented in the shape. Then, as shown in FIGS. 10A and 10B, the core mold 62a is moved backward. At this time, the depth of the bridge groove 52c is increased by providing a thick portion 52f on the back surface of the base material 52 that forms the bridge groove 52c, so that the front end surface 62c is always the design surface 51a rather than the opening of the bridge groove 52c. Must be located on the side. By providing this thick portion 52f, the sealing performance by the base material 52 around the ridge 62b is ensured. Thereafter, the second cavity 66 is filled with a liquid thermosetting paint and cured to form the surface material 53 on the surface of the substrate 52. At this time, the bridge portion 53 d is formed by the paint in the communication path 67.

  In this way, the difference between the thickness of the bridge portion 53d and the thickness of the convex portion 52a becomes extremely large, and when the light is irradiated from behind the pressing member 11 regardless of the position of the light source, it is reflected in the light transmitting portion 52b. Since the shadow of the bridge portion 53d to be inserted becomes even thinner, the design of the pressing member 11 is improved.

-You may use the translucent display body of the said embodiment for the emblem, back panel, center pillar, etc. of the front grille of a vehicle.
-The light transmission part 12b and the light-shielding part may not be flush with each other. For example, the tip surface of the convex portion 12 a of the base material 12 may protrude from the surface of the surface material 13, or the tip surface may be recessed from the surface of the surface material 13.

-The surface which extends in parallel with the direction which the said 1st and 3rd type | molds 22 and 25 open from the said base material 12 is abbreviate | omitted, and it is good also considering the base material 12 as flat form.
· Predetermined characters, etc. displayed on the design surface 11a of the pressing member 11 have an annular portion such as “B” or “D” or the numbers “6” or “8” in addition to the alphabet “A”. If it is.

  -You may abbreviate | omit the taper shape of the side surface of the said protrusion 22b. Also in this case, the state in which the side surface of the protrusion 22b is in contact with the inner surface of the bridge groove 12c is maintained in the state in which the core mold 22a is moved backward, so the side surface of the protrusion 22b and the inner surface of the bridge groove 12c The sealing performance between the two is ensured.

The perspective view of the switch of embodiment. FIG. 2 is a sectional view taken along line 2-2 in FIG. 1. The principal part enlarged view of FIG. (A) is sectional drawing which shows the effect | action at the time of base-material shaping | molding, (b) is sectional drawing when a 2nd cavity is formed with a base material and a 3rd type | mold. (A) is principal part sectional drawing in the 5a-5a line | wire of Fig.4 (a), (b) is the principal part expanded sectional view of the 5b-5b line | wire of (a). (A) is principal part sectional drawing when a core type | mold is moved backward, (b) is a principal part expanded sectional view in the 6b-6b line | wire of (a). (A) is principal part sectional drawing which shows the effect | action at the time of the base-material shaping | molding of a modification, (b) is a principal part expanded sectional view in the 7b-7b line | wire of (a). (A) is principal part sectional drawing when retreating the core type | mold of a modification, (b) is a principal part expanded sectional view in the 8b-8b line | wire of (a). (A) is principal part sectional drawing which shows the effect | action at the time of the base-material shaping | molding of a modification, (b) is a principal part expanded sectional view in the 9b-9b line | wire of (a). (A) is principal part sectional drawing when retreating the core type | mold of the example of a change, (b) is a principal part expanded sectional view in the 10b-10b line | wire of (a).

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Press member as translucent display body, 11a, 31a, 51a ... Design surface, 12, 32, 52 ... Base material, 12a, 32a, 52a ... Projection part, 12b, 32b, 52b ... Light which comprises a design surface Transmission part, 12c, 32c, 52c ... Bridge groove, 13,33,53 ... Surface material, 13b, 33b, 53b ... Inner light shielding part, 13c, 33c, 53c ... Outer light shielding part, 13d, 33d, 53d ... Bridge part, 22, 42, 62 ... first type, 22a, 42a, 62a ... core type, 22b, 42b, 62b ... ridge, 22c, 42c, 62c ... tip end surface of ridge, 23, 43, 63 ... second type, 24 ... 1st cavity, 25, 45, 65 ... 3rd type | mold, 26, 46, 66 ... 2nd cavity, 27, 47, 67 ... Communication path.

Claims (1)

A base material made of a resin having light permeability, and a surface material made of a light-shielding paint formed so as to cover the surface of the base material in a layer form, the design surface comprising a light transmissive portion, the light An inner light-shielding portion surrounded by the light-transmitting portion; and an outer light-shielding portion disposed outside the light-transmitting portion. The light-transmitting portion is formed by a convex portion formed on the surface of the base material. The inner light-shielding portion and the outer light-shielding portion are formed from the surface material, and a bridge groove is formed in the back surface of the base material to form a bridge portion in the bridge groove. The inner light-shielding portion and the outer light-shielding portion A mold for in-mold coating molding used for manufacturing a translucent display body connected to the back surface of the base material by the bridge portion,
  A first mold, a second mold, and a third mold are provided, the base material is molded by the first mold and the second mold, and the surface material is molded on the surface of the base material by the first mold and the third mold. And a core mold for forming the bridge groove protrudes from the cavity surface of the first mold.
  The core mold is configured to be able to move backward in the first mold and the bridge portion is formed, and the core mold in a state of being moved backward is in contact with the inner surface of the bridge groove, and the tip The surface is located on the design surface side from the back surface of the base material forming the bridge groove,
  The mold for in-mold coating molding characterized in that the side surface of the core mold has a tapered shape that becomes narrower in the backward movement direction.

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