JP2010097131A - Partial light-shielding plate material and light-transmissive display - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a partial light-shielding plate material in which a light-shielding part can be subjected to electroplating, and to provide a transmissive display in which the light-shielding part (a) is subjected to electroplating. <P>SOLUTION: The partial light-shielding plate material includes: a transmissive part which is made of light-transmissive resin and transmits light in the plate thickness direction; and a light shielding part which is made of a light-shielding resin on at least one plate surface side and becomes non-transmissive in the plate thickness direction, wherein at least a part of the transmissive part assumes a ring-closure shape extended such that a ring is closed on the plane surface, light-shielding resins constituting a light-shielding part inside the transmissive part of the ring-closure shape and a light-shielding part outside the transmissive part of the ring-closure shape traverse the transmissive part to each other and are made continuous by a bridge part (c) made by the light-shielding resin protruded from the other side plate surface of the partial light-shielding plate material. Further, the light-shielding resin is made of a conductive light-shielding resin 4. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a partially light-shielding plate material and a light-transmitting display body, which are partially provided with a light-transmitting portion, for example, a light-transmitting display body suitably used for a display panel of an instrument panel of an automobile, The present invention relates to a partially light-shielding plate material for manufacturing a body.

  A translucent display body partially provided with a translucent portion is widely used for a speed display plate of an instrument panel of an automobile. A lamp is placed on the back side of the translucent display, and when this lamp is turned on, light reaches the front through the translucent part of the translucent display, so that characters, symbols, etc. can be clearly seen. Can do.

  An example of the structure of the translucent display is shown in FIGS. 8 (a) and 8 (b). FIG. 8A is a perspective view of the translucent display body, and FIG. 8B is a cross-sectional view taken along the line BB of FIG. As for this translucent display body 1, the lower surface side as a whole is comprised with the translucent resin 2, and most upper surface sides are comprised with the light-shielding resin 3. FIG. When a part of the translucent resin 2 is exposed on the upper surface side, a character-shaped translucent part “7” is formed. The translucent display 1 is formed by two-color molding in which the translucent resin 2 is first injection-molded and then the light-shielding resin 3 is injection-molded.

  With such a translucent display formed by two-color molding, as shown in FIGS. 9A and 9B, it is not possible to mold a translucent display that displays characters having a ring-shaped portion such as “0”. . That is, since the “0” -shaped translucent portion a extends like a dike, the translucent display body is formed by a two-color molding method in which the translucent resin 2 is first ejected and then the light-shielding resin is ejected. Even if it tries to shape | mold, light-shielding resin cannot be filled into the inner area | region b of the translucent part a of "0" shape. 9A is a perspective view, and FIG. 9B is a cross-sectional view taken along line BB in FIG.

  Although FIG. 9 relates to “0”, the same applies to numbers such as “4”, “6”, “8”, “9”, and various characters and symbols having an annular portion.

  In order to solve such a difficulty, as shown in FIG. 10, by providing a bridging portion c for bridging the inner light-shielding resin 3 and the outer light-shielding resin 3 of the closed ring-shaped translucent portion a, It has been devised that the light-shielding resin 3 can be filled into the inside of the closed light-transmitting part a via the tangle c by two-color molding (for example, Patent Documents 1 and 2 below).

  10A is a perspective view of the upper surface of the translucent display body, FIG. 10B is a sectional view taken along line BB of FIG. 10A, and FIG. 10C is a perspective view of the lower surface of the translucent display body. ) Is a sectional view taken along the line DD of (c).

In FIG. 10, the light shielding resin 3 inside the “0” -shaped translucent portion a and the light shielding resin 3 outside are bridged by a bridging portion c. If it is this structure, if the translucent resin 2 will be injection-molded first and then the light-shielding resin 3 will be injection-molded, it will also shield the inside of the “0” -shaped translucent portion a through the bridge portion c. The functional resin 5 is filled. The bridging portion c crosses the annular translucent portion a and protrudes from the lower surface of the plate-like body. The bridging portion c is continuous with the light shielding resins 3 and 3 through the plate in the thickness direction along the light transmitting portion a of the light transmitting resin 2.
Japanese Patent Fair 8-25206 JP-A-2-111513

I. The light-shielding part of the conventional partial light-shielding plate is shielded by a light-shielding resin. Such a light-shielding part is made of dark resin and has low design. Moreover, when the thickness of the light shielding part is small, the light shielding property may be insufficient.

  In order to impart designability, it is conceivable to impart metallic luster by performing electroless plating using an ABS resin as a light-shielding resin and then performing electroplating of nickel, copper, chromium, or the like.

  However, when electroless plating is applied to the light-shielding resin portion of the partially light-shielding plate having the structure shown in FIG. 10, the inner and outer sides of the ring-shaped light-transmitting portion are annular light-transmitting portions and light-transmitting resin layers. Since the outer and inner sides of the closed ring-shaped light-transmitting portion are not electrically connected to each other, the inner side of the closed-ring shaped light-transmitting portion is not electroplated.

An object of this invention is to provide the partial light-shielding board | plate material which can electroplate to a light-shielding part, and the translucent display body by which the light-shielding part was electroplated.
II. In a translucent display body having a conventional bridging portion, when viewed from the front, the bridging portion traversing the translucent portion is visually recognized. For this reason, the missing phenomenon of the ring-shaped translucent part, in which “0” looks like “C” and “8” looks like “3”, is unavoidable.

  In one aspect, the present invention has an object to provide a translucent display body in which the closed ring-shaped light-transmitting portion is free from a chipping phenomenon, and the closed ring-shaped light-transmitting portion is viewed in a continuous ring shape.

  The partially light-shielding plate material according to claim 1 is a light-transmitting portion made of a light-transmitting resin that transmits light in the plate thickness direction, and at least one plate surface side is made of a light-shielding resin, and is not light-transmitting in the plate thickness direction. A partially light-shielding plate member having a light-shielding portion, and at least a part of the light-transmitting portion has a closed ring shape extending in a ring shape on the plate surface. The light-shielding resins constituting the inner light-shielding portion and the outer light-shielding portion are continuous by a bridging portion made of the light-shielding resin that crosses the light-transmitting portion and protrudes from the other plate surface of the partial light-shielding plate material. In the partially light-shielding plate member, the light-shielding resin is made of a conductive light-shielding resin.

  A partially light-shielding plate material according to claim 2 is characterized in that, in claim 1, the light-shielding resin having conductivity is made of a resin composition containing a conductive filler.

  The partially light-shielding plate material according to claim 3 is characterized in that, in claim 2, the resin composition containing the conductive filler is composed of an ABS resin composition containing the conductive filler.

  The partial light-shielding plate material according to claim 4 is the light-shielding resin according to any one of claims 1 to 3, wherein a part of the light-shielding portion is formed from the one plate surface to the other plate surface. It is characterized by being.

  A partially light-shielding plate material according to a fifth aspect is characterized in that, in any one of the first to fourth aspects, the light-shielding portion of the one plate surface is electroplated.

  The partial light-shielding plate material of claim 6 is any one of claims 1 to 4, wherein the conductive light-shielding resin has higher electroless plating properties than the light-shielding resin, The light-shielding portion is subjected to electroless plating, and electroplating is performed thereon.

  The translucent display body of Claim 7 consists of the partial light-shielding board | plate material of Claim 5 or 6.

  A light-transmitting display body according to an eighth aspect is manufactured by removing the bridging portion from the partially light-shielding plate material according to the fifth or sixth aspect.

  In the partial light-shielding plate material of the present invention, since the light-shielding resin is made of a conductive light-shielding resin, the light shielding part can be electroplated.

  The translucent display of the present invention is obtained by electroplating the conductive resin constituting the light shielding part of the partial light shielding plate material, and the light shielding part has a beautiful metal plating surface.

  By removing the bridging portion from the translucent display body, the closed ring-shaped translucent portion is visually recognized as a continuous ring in which the ring is not interrupted.

  In addition, when electroplating is performed after electroless plating, the adherence of the electroplating layer is improved.

  In this partial light-shielding plate material and translucent display, when a portion made of a conductive light-shielding resin is provided over the entire thickness direction of the plate, when the light-shielding portion is formed by two-color molding, the conductive light-shielding resin Easily fills every corner of the cavity. In addition, the conductivity of the molded partial light-shielding plate and the conductive light-shielding portion of the translucent display is improved.

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

  FIG. 1A is a cross-sectional view of a partially light-shielding plate 7 according to an embodiment, FIG. 1B is a cross-sectional view of a translucent display body 8 according to the embodiment, and FIG. It is sectional drawing of the translucent display body 9 which was made.

  The structure of the partially light-shielding plate 7 in FIG. 1 (a) is the same as that described above except that the conductive light-shielding resin 4 is used as the light-shielding resin and that the translucent part a slightly protrudes from the plate surface. 10 (a) to (c).

  That is, the lower surface side of the partial light-shielding plate material 7 is made of the translucent resin 2, and a part of the translucent resin 2 protrudes upward to form a translucent portion a. The upper surface side of the partial light-shielding plate 7 is composed of the conductive light-shielding resin 4 except for the light transmitting part a. In this embodiment, the translucent part a slightly protrudes upward (for example, about 0.1 to 2.0 mm) from the upper surface of the light shielding resin 4.

  The translucent part a has a closed ring shape such as “0”, “4”, “6”, “8”, and appears in a ring shape on the plate surface (upper surface in FIG. 1) of the partially light-shielding plate material 7. The light shielding resin 4 in the inner region b and the light shielding resin 4 in the outer region of the closed ring-shaped translucent portion a are bridged by a bridging portion c. This bridging portion c protrudes from the lower surface of the partially light-shielding plate material. The bridging portion c penetrates the partially light-shielding plate material 7 in the thickness direction along the translucent portion a.

  This partial light-shielding plate 7 is formed by two-color molding. That is, first, the translucent resin 2 is injected, and then the conductive light-shielding resin 4 is injected. When the conductive light-shielding resin 4 is injected, the conductive light-shielding resin 4 is supplied from the injection molding machine to the outer region of the closed ring-shaped translucent portion a. Since the conductive light-shielding resin 4 flows into the inner region b of the closed ring-shaped translucent portion a through the bridging portion c, the inner region b is sufficiently filled with the conductive light-shielding resin 4.

The size of the bridging portion c may be determined experimentally as appropriate according to the size of the inner region b, the resin material, and the like. If the minimum cross-sectional area of the bridging portion c is too small, the resin cannot be sufficiently circulated, and the conductivity may be insufficient. Further, if the bridging portion c is excessively large, it may take time to remove. Therefore, when used as a display board or the like of an automotive speedometer, the cross-sectional area of the bridging portion c is 0.01～4Mm ² particularly 0.1 to 2 mm ² particularly about 0.2 to 1 mm ² is preferred.

  Since the conductive light-shielding resin 4 has conductivity, the plating layer 5 can be formed by electroplating as shown in FIG. 1 (b). Thereby, the translucent display body 8 excellent in aesthetics in which the plate surface other than the translucent part a is a metal plating surface is obtained.

  When the bridging portion c protruding from the lower surface of the translucent display body 8 (the back surface of the product translucent display body) is removed by cutting, breaking, polishing, etc., the entire closed ring-shaped translucent portion a is exposed on the lower surface. The display body 9 is obtained.

  With this translucent display body 9, when viewed from the front (the upper surface in FIG. 1 (c)), there is no bridging portion c that crosses the translucent portion, so that the translucent portion a is completely continuous. It is visually recognized as a closed ring shape. That is, “0” does not look like “C” and “8” does not look like “3” at all.

  In FIG. 1, the bridging portion c is provided only in the light transmitting portion a and the vicinity thereof, but as in the partially light-shielding plate material 7A in FIG. You may extend so that it may straddle.

  In addition, as shown in FIG. 2, all the conductive materials that are adjacent to the bridging portion c and have an electrically conductive light-shielding resin 4 penetrating the translucent display body in the thickness direction in the outer region of the closed ring-shaped translucent portion a. A light-shielding resin region d may be provided. When this region d is provided, when the conductive light-shielding resin 4 is injection-molded when the partial light-shielding plate material 7A is molded in two colors, the conductive light-shielding resin 4 passes through this region d and has a wide range in the cavity. So that the so-called resin periphery is good. Thereby, the conductive light-shielding resin 4 can be easily filled to every corner of the cavity.

  Further, since the region d is conductive, the electric resistance of the partial light-shielding plate 7A is also reduced.

  In FIG. 2, a plating layer 5 is formed by electroplating directly on the conductive light-shielding resin 4. However, as shown in FIG. 11, the conductive light-shielding resin 4 is first formed by electroless plating. A conductive electroless plating layer 6 may be formed thereon, and the electroplating layer 5 may be formed on the electroless plating layer 6. Thereby, the adherence of the electroplating layer is improved. In this case, as the conductive light-shielding resin 4, a resin such as ABS or ABS alloy resin having higher electroless property than the light-transmitting resin 2 (that is, a plating layer is easily formed by electroless plating) is used.

  In one aspect of this embodiment, like the partially light-shielding plate material 7C in FIG. 12, the outer edge side of the plate material 7C is formed with the conductive light-shielding resin 4 over the entire plate thickness direction from the bridge portion c. The electroless plating layer 6 is continuously formed from the upper surface and the side end surface of the plate 7C to the bridge portion c on the lower surface, and the electroplating layer 5 is formed on the electroless plating layer 6 so as to transmit light. The display body 8C may be used, and then the bridging portion c may be removed to manufacture the translucent display body 9C. In this way, the electroless plating layer 5 is formed in a state in which the electroless plating layer 6 on the upper surface and the electroless plating layer 6 on the bridging portion c are directly conducted by the electroless plating layer 6. The electrical resistance up to b is reduced, and the adherence of the electroplating layer 5 in the inner region b is improved.

  With reference to FIG. 3 to FIG. 7, another embodiment of the partially light-shielding plate material and the translucent display will be described. 3 (a) is a front view of the partially light-shielding plate member 10, FIG. 3 (b) is a sectional view taken along line BB in FIG. 4 (a), and FIG. 4 (a) is IV- in FIG. 3 (b). IV sectional view, FIG. 4 (b) is a sectional view taken along the line BB of FIG. 5 (a), FIG. 5 is a rear view of the partial light shielding plate 10, and FIG. 6 uses this partial light shielding plate 10. 7 is a cross-sectional perspective view of the translucent display member 11, and FIG. 7 is a cross-sectional perspective view of the partially light-shielding plate 12 from which the bridging portion is removed from the translucent display member 11 of FIG.

  In the partial light-shielding plate 10, most of the back surface side is composed of the translucent resin 2, and most of the front surface (upper surface in FIG. 4) side is composed of the conductive light-shielding resin 4. A part of the translucent resin 2 penetrates the conductive light-shielding resin 4 on the front surface and protrudes, for example, by about 0.1 to 2.0 mm, thereby constituting a translucent part a. In this embodiment, the closed ring-shaped translucent portion a has a shape of a number “0”, “4”, or “8”.

  The conductive light-shielding resin 4 in the inner region b of the closed ring-shaped translucent part a and the conductive light-shielding resin 4 in the outer region are continuous by a bridging portion c made of the conductive light-shielding resin 4. The bridging portion c protrudes from the back surface of the partial light shielding plate 10.

In this embodiment, as shown in FIG. 5, the entire conductive light-shielding resin region (entirely from the front surface to the back surface of the plate surface becomes a conductive light-shielding resin) along the entire peripheral edge portion of the partial light-shielding plate material 10. and it has area) d ₁ is provided.

Further, the entire conductive light shielding resin region d ₂ so as to connect a plurality of closely spaced bridging portion c is provided, so as to connect the entire conductive light-shielding resin region d ₂ between the entire conductive light-shielding resin region _{d 3} is provided. Portion of the total conductive light shielding resin region d ₂ is continuous in all conductive shielding resin region d ₁ of the peripheral portion.

As described above, the all-conductive light-shielding resin region d ₁ is provided on the entire periphery, and all the conductive light-shielding resin regions d ₂ and d ₃ are provided like a mesh so as to be continuous with the all-conductive light-shielding resin region d _1. Therefore, when the conductive light-shielding resin 4 is injection-molded, the conductive light-shielding resin is easily filled to every corner. That is, the partial light-shielding plate 10 is also formed by two-color molding in which the translucent resin 2 is first injection-molded and then the conductive light-shielding resin 4 is injection-molded. In the molded article that is _first molded by injection of the translucent resin 2, the d ₁ , d ₂ , and d ₃ portions are continuous groove-like voids. For this reason, when the conductive light-shielding resin 4 is injected, the conductive light-shielding resin 4 easily spreads throughout the cavity along the groove-like space. Thereby, the partial light-shielding board | plate material 10 without a defect, such as a void, can be shape | molded efficiently. Further, since the all conductive light-shielding resin regions d ₁ , d ₂ , and d ₃ are stretched over the entire area of the partial light-shielding plate material, the electric resistance is reduced over the entire area of the partial light-shielding plate material.

Especially when performing electroplating after subjected to electroless plating, electroless plating layer applied on all bridge surface is conductive with electroless plating layer 6 on the top surface by the entire conductive light-shielding resin region d ₂ Therefore, since the electrode is directly attached to the back surface substantially, the electrical resistance to the inner side b portion of the closed ring-shaped translucent portion is reduced, and the adherence of the electroplating layer 5 is improved.

  As shown in FIG. 6, the conductive light-shielding resin of the partial light-shielding plate 10 is preferably electroless-plated to form an electroless-plated layer 6, and then a plated layer 5 is formed by electroplating to provide a translucent display. 11 is assumed. Thereafter, the bridging portion c is removed from the translucent display body 11 by cutting, grinding, cutting, or the like, thereby obtaining the translucent display body 12 shown in FIG.

  In this way, the conductive light-shielding resin 4 is sufficiently filled also in the inner region of the closed ring-shaped light-transmitting part a, and a beautiful light-transmitting display body 12 in which the conductive light-shielding resin 4 is plated is obtained. It is done.

  As the plating metal, chromium (trivalent or hexavalent), gold, silver, the same, tin, nickel, phosphorus, ruthenium, palladium, cobalt, and alloys thereof are preferable. Copper that is compatible with the electroless plating layer may be plated, then nickel may be plated, and chromium may be plated thereon.

The conductive light-shielding resin 4 preferably has a volume resistivity of 1 × 10 ³ Ωcm or less, desirably 1 × 10 ² Ωcm or less, more preferably 5 × 10 ¹ Ωcm or less, and particularly preferably 1 × 10 ¹ Ωcm or less. In particular, when electroplating a noble metal such as chromium in decorative plating, a high current density is required, and therefore, it is desirable that it is 5 × 10 ¹ Ωcm or less.

  As the conductive light-shielding resin 4, a conductive filler is preferably added to improve conductivity.

  Examples of the conductive filler used in the light-shielding resin composition include various types of carbon black, graphite, and metal fillers such as aluminum, silver, copper, zinc, nickel, stainless steel, brass, and titanium (particulate, flaky, fibrous) Or pitch-based carbon fiber, PAN-based carbon fiber, carbon nanofiber, carbon nanotube carbon-based fiber, and the like.

  A low melting point metal such as tin or an alloy of tin and lead, silver, zinc or the like may be contained and melt-dispersed in the resin.

  Further, a composite conductive filler in which a metal such as nickel or copper is coated on an insulating filler such as carbon fiber, graphite, glass fiber, or aramid fiber can also be used.

  As the conductive filler, a single filler may be used, or a plurality of fillers may be used in combination. It is desirable to use a fibrous filler, particularly a metal fiber or a metal-coated fiber, as at least a part of the filler, because excellent conductivity can be obtained with a small amount of addition.

  In the case of a fibrous filler, the fiber diameter is preferably 1 nm to 50 μm, particularly preferably 0.5 μm to 30 μm. If the fiber diameter is too thin, uniform dispersion to the resin becomes difficult, and if the fiber diameter is large, the appearance is impaired.

  The aspect ratio (length / diameter ratio) of the fiber is preferably 5 or more, particularly 10 or more, and more preferably 100 to 1000. As the aspect ratio is larger, conductivity can be obtained with a smaller addition amount. However, if the aspect ratio is too large, appearance defects and molding defects are likely to occur.

  As the translucent resin, polycarbonate, polymethyl methacrylate, polyarylate, polyethylene terephthalate, polysulfone, polyether sulfone, polypropylene, polyethylene, polymethylpentene and the like are used, and among them, polycarbonate and polymethyl methacrylate resin are preferable.

  There is no limitation in particular as light-shielding resin. As the light-shielding resin capable of electroless plating, in addition to ABS alloy resins such as ABS resin and ABS / polycarbonate, known resin materials capable of electroless plating can be used.

  Among these, a resin material mainly composed of ABS is desirable in terms of cost and plating adhesion.

  Next, a preferred example of a method of electroless plating and then electroplating on a partially light-shielding plate made of a resin molded product will be described.

  First, dirt such as dust and oil adhering to the surface of the resin molded product to be electrolessly plated is removed. Next, the surface of the resin molded product is chemically roughened by etching the resin molded product using an etching solution. Next, the surface of the resin molded product is neutralized with an acid to reduce and remove hexavalent chromium, which is a kind of etching component. Next, a catalyst is performed on the resin molded product. In this catalyst (catalyzer) step, it is preferable that the molded product is immersed in an aqueous solution of stannous chloride and hydrochloric acid, then washed with water, and tin is adsorbed on the surface of the molded product.

  As a result, a catalyst (such as a Pd—Sn compound) having a strong adsorptive power and a reducing power is adsorbed on the roughened surface of the resin molded product.

  Next, an accelerator is applied to the resin molded product to remove Sn adhering to the surface of the resin molded product and activate Pd. In the accelerator step, it is preferable to immerse the molded article in an aqueous solution of palladium chloride and hydrochloric acid, wash with water, and perform a substitution reaction of palladium and tin.

  Next, an electroless plating layer is formed by immersing the resin molded product in an electroless plating tank and performing electroless plating on the resin molded product. When ABS or ABS alloy-based resin is used as the conductive light-shielding resin and polycarbonate is used as the light-transmitting resin, an electroless plating layer is formed only on the ABS or ABS alloy-based resin, and high conductivity is imparted.

  Next, the resin molded product is immersed in an electroplating tank and electroplated.

  As an example of the electroplating process, a decorative electroplating process by sequentially performing copper plating, nickel plating, and chromium plating will be described in detail.

As the copper sulfate plating solution, a known bright copper sulfate plating solution can be used. For example, a plating bath in which a known brightener is added to an aqueous solution containing about 100 to 250 g / l of copper sulfate, about 20 to 120 g / l of sulfuric acid, and about 20 to 70 mg / l of chlorine ions can be used. The conditions for copper sulfate plating may be the same as usual. For example, plating may be performed at a liquid temperature of about 25 ° C. and a current density of about 3 A / dm ² , and plating to a predetermined film thickness.

As the nickel plating solution, a normal Watt bath can be used. That is, a commercially available nickel plating bath brightener added to an aqueous solution containing about 200 to 350 g / l of nickel sulfate, about 30 to 80 g / l of nickel chloride, and about 20 to 60 g / l of boric acid can be used. The plating conditions may be the same as usual. For example, electrolysis is performed at a liquid temperature of about 55 to 60 ° C. and a current density of about 3 A / dm ² , and plating may be performed to a predetermined film thickness.

As the chromium plating solution, a normal sergeant bath can be used. That is, an aqueous solution containing about 200 to 300 g / l of chromic anhydride and about 2 to 5 g / l of sulfuric acid can be used. The plating conditions are a liquid temperature of about 45 ° C. and a current density of about 20 A / dm ² , and a predetermined film thickness. It is sufficient to perform plating. After plating, the plate is washed with water and dried to obtain a plated partially light-shielding plate.

Example 1
The partially light-shielding plate material shown in FIGS. 3 to 6 was produced as follows.

  Polycarbonate (Iupilon S-3000 manufactured by Mitsubishi Engineering Plastics) was used as the translucent material.

  As the conductive light-shielding resin, 75 parts by weight of resin coated with nickel-coated carbon fiber (Toho Tenax Co., Ltd. MC-HTA-C6-US) as the conductive filler and ABS resin (Nippon A & L Co., Ltd., Clarastic AP-8A). The mixture was blended at a ratio of 25 wt.% And melt kneaded with a twin-screw kneading extruder (PCM45 barrel temperature 240 ° C., 100 RPM, manufactured by Ikegai Co., Ltd.) (volume resistivity 13.2 Ωcm).

Using a 75 ton injection molding machine, a translucent part was formed from polycarbonate to obtain a primary molded body having a thickness of 1.5 mm. Then, the said light-shielding resin composition was inject | emitted and the partial light-shielding board | plate material of thickness (except a bridge part) 3mm was manufactured. The protruding height of the bridging portion c is 1 mm, and the extending length is 3.6 mm. As shown in the figure, there are three types of widths, large, medium, and small. The width is 3.5 mm, the middle is 1.5 mm, and the small is 1 mm. The minimum cross-sectional area of the bridge C is a large 12.6 mm ^2, a 0.8 mm ² at 1.8 mm ^2, smaller in the inside.

  Next, the molded product was etched with a chromic acid solution (Cr03 / H2SO4), and then the surface was activated with a mixed solution of palladium chloride, stannous chloride and hydrochloric acid, and H2SO4, and then nickel electroless plating Was given.

Next, a cathode was attached to the hole in FIG. 3 (a) (the white spot in FIG. 3 (a)) and electroplated. As the electroplating, electrolytic copper plating (in copper sulfate and sulfuric acid aqueous solution, current density 5 A / dm ² 20 minutes), electro nickel plating (in nickel sulfate and boric acid aqueous solution, current density 5 A / dm ² 20 minutes) Then, electrochromic plating (20 A / dm ^{2 for} 5 minutes in chromic anhydride and sulfuric acid aqueous solution) was sequentially performed to form a plating film of electroplating 9 μm, electroplating nickel 4.5 μm, and chromium plating 0.1 μm.

  Thereafter, the bridging portion c was removed by cutting. Most of the removal of the bridging portion was performed using a milling machine. Further, the middle part was easily cut by hand without using a tool, and the small part was easily cut by hand.

  In this translucent display board, the translucent part a was colorless and transparent, and the bridging part c was not visually recognized at all. Further, except for the translucent part a, it was a beautiful metal chrome plating surface.

Comparative Example 1
A partially light-shielding plate and a light-transmitting display were produced in the same manner as in Example 1 except that no conductive filler was blended in the ABS resin, but the electroplating layer was not deposited at all.

It is sectional drawing of the partial light-shielding board | plate material which concerns on embodiment, and a translucent display body. It is sectional drawing of the translucent display body which concerns on another embodiment. FIG. 3 (a) is a front view of the partially light-shielding plate, and FIG. 3 (b) is a cross-sectional view taken along the line BB of FIG. 3 (a). 4 (a) is a sectional view taken along line IV-IV in FIG. 3 (b), and FIG. 4 (b) is a sectional view taken along line BB in FIG. 4 (a). It is a reverse view of a partial light-shielding board | plate material. It is a cross-sectional perspective view of the translucent display body 11 using the partial light-shielding board | plate material. It is a cross-sectional perspective view of the partial light-shielding board | plate material which removed the bridge part from the translucent display body of FIG. It is explanatory drawing of a prior art example. It is explanatory drawing of another prior art example. It is explanatory drawing of another prior art example. It is sectional drawing of the translucent display body which concerns on another embodiment. It is sectional drawing which shows another embodiment, (a) is sectional drawing at the time of electroless plating layer formation, (b) is sectional drawing at the time of electroplating layer formation, (c) is after bridge part removal It is sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Partial light-shielding board material 2 Translucent resin 3 Light-shielding resin 4 Conductive light-shielding resin 5 Electroplating layer 6 Electroless plating layer 7, 7A, 7C, 10 Partial light-shielding board material 8, 8B, 8C, 9, 9C, 11,12 translucent display body a light transmitting portion b ring closure of the inner region c bridging portion _{d, d 1, d 2,} d 3 entire conductive light-shielding resin region

Claims (8)

A light-transmitting portion made of a light-transmitting resin that transmits light in the plate thickness direction;
A partially light-shielding plate material having at least one plate surface side made of a light-shielding resin and having a light-shielding portion that is not light-transmissive in the thickness direction of the plate, and at least a part of the light-transmitting portion is It has a closed ring shape that extends into a closed ring shape,
The light shielding resin constituting the inner light shielding part and the outer light shielding part of the closed ring-shaped light transmitting part crosses the light transmitting part and projects from the other plate surface of the partial light shielding plate material. In the partial light-shielding plate material that is continuous by the bridge part
A partially light-shielding plate material, wherein the light-shielding resin comprises a conductive light-shielding resin.   2. The partially light-shielding plate material according to claim 1, wherein the conductive light-shielding resin comprises a resin composition containing a conductive filler.   3. The partially light-shielding plate material according to claim 2, wherein the resin composition containing a conductive filler comprises an ABS resin composition containing a conductive filler.   4. The partial light shielding according to claim 1, wherein a part of the light shielding portion is made of a light shielding resin from the one plate surface to the other plate surface. Board material.   The partial light-shielding plate material according to any one of claims 1 to 4, wherein the light-shielding portion of the one plate surface is subjected to electroplating. In any 1 item | term of the Claims 1 thru | or 4, the said light-shielding resin which has the electroconductivity is a thing with higher electroless plating property than the said light-shielding resin,
A partially light-shielding plate material, wherein electroless plating is applied to the light shielding portion, and electroplating is performed thereon.   The translucent display body which consists of a partial light-shielding board | plate material of Claim 5 or 6.   The translucent display body manufactured by removing the said bridge part from the partial light-shielding board | plate material of Claim 5 or 6.

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