JP7023178B2 - Molding mold, manufacturing method of interior material for vehicles, and manufacturing method of molding mold - Google Patents

Description

The technique disclosed herein relates to a molding die, a method for manufacturing an interior material for a vehicle, and a method for manufacturing a molding die.

Patent Document 1 discloses a resin molding die and a method for molding a resin material using this die. The molding die described in Patent Document 1 has a molding surface in which the plated crystal nuclei generated by the plating treatment are coarsened to form fine irregularities, and the resin molded product is molded using this molding die. It is described that the texture (matte feeling) of the resin molded product can be improved.

Japanese Unexamined Patent Publication No. 8-72065

However, in the configuration disclosed in Patent Document 1, the properties of the plating layer are not sufficiently disclosed, and it is unclear what kind of plating layer should be formed to reduce the brightness and glossiness of the molded product. ..

As a result of diligent research, the inventors of the present application have newly found the properties of the plating layer capable of reducing the brightness and glossiness of the molded product. On the other hand, when the inventor of the present application forms a textured pattern on the surface of a molded product by using a molding die having such a plating layer, the molding die has fine irregularities, which is desired. We have confirmed a new problem that it is not possible to form a contrast grain pattern.

The technique disclosed in the present specification has been completed based on the above circumstances, and it is possible to appropriately adjust the contrast of the embossed pattern while reducing the brightness and glossiness of the surface of the molded product. It is an object of the present invention to provide a molding die capable of molding a molded product having excellent designability, a method for manufacturing an interior material for a vehicle, and a method for manufacturing a molding die.

In order to solve the above problems, the molding die disclosed in the present specification includes a mold base material having convex portions and concave portions forming a concave-convex shape for forming a grain pattern on the surface of the molded product, and the convex portion. A plating layer having fine irregularities finer than the uneven shape, which is selectively formed on one of the protruding end surface of the portion and the inner surface of the concave portion, is provided.

According to such a molding die, when a valley portion is formed by a convex portion and a mountain portion is formed by a concave portion to form a grain pattern on the surface of a molded product, a plating layer is formed on the protruding end surface of the convex portion. If this is the case, the bottom surface of the valley can be roughened by the fine irregularities, and if the plating layer is formed on the inner surface of the recess, the outer surface of the mountain can be roughened by the fine irregularities. Can be transformed into. Therefore, the contrast of the grain pattern can be appropriately adjusted while reducing the brightness and glossiness of the surface of the molded product, and the molded product having excellent design can be molded.

The plating layer may have the fine irregularities having an average protrusion diameter of 0.1 μm to 2.0 μm. According to such a configuration, the brightness and glossiness of the surface of the molded product can be suitably reduced.

The method for manufacturing an interior material for a vehicle disclosed in the present specification is a method for manufacturing an interior material for a vehicle in which the interior material for a vehicle is molded by using the above-mentioned molding die, and the valley portion is formed by the convex portion and the valley portion is formed. When the mountain portion is formed by the concave portion to form the grain pattern on the design surface of the vehicle interior material and the plating layer is formed on the protruding end surface of the convex portion, the fine unevenness causes the said. When the bottom surface of the valley portion is roughened and the plating layer is formed on the inner surface of the concave portion, the outer surface of the mountain portion is roughened by the fine unevenness.

According to such a method for manufacturing an interior material for a vehicle, the contrast of the grain pattern can be appropriately adjusted while reducing the brightness and glossiness of the surface of the interior material for the vehicle, and the interior for the vehicle is excellent in design. The material can be molded.

The method for manufacturing a molding die according to the first aspect is formed on a mold base material having convex portions and concave portions forming a concave-convex shape for forming a textured pattern on the surface of a molded product, and a protruding end surface of the convex portions. In addition, it is a manufacturing method of a molding die including a plating layer having fine irregularities finer than the uneven shape, in which the inner surface of the concave portions is covered with a coating material that does not melt under plating treatment conditions, and the convex portions are The coating step of exposing the protruding end surface and the metal base material whose inner surface of the concave portion is coated with the coating material are subjected to a plating treatment to form the plating layer on the protruding end surface of the convex portion. The plating layer forming step and the coating material are removed from the mold base material in which the plating layer is formed on the protruding end surface of the convex portion, and the plating layer is selectively formed on the protruding end surface of the convex portion. The coating material removal step of obtaining the molding die in which the above-mentioned is formed is provided.

According to the molding die manufactured by such a molding die manufacturing method, when the valley portion is formed by the convex portion and the mountain portion is formed by the concave portion to form a grain pattern on the surface of the molded product, it is fine. The bottom surface of the valley can be roughened by the unevenness. Therefore, it is possible to increase the contrast of the grain pattern while reducing the brightness and glossiness of the surface of the molded product, and it is possible to mold the molded product having excellent design.

In the method for manufacturing a mold according to the second aspect, a mold base material having convex portions and concave portions forming a concave-convex shape for forming a textured pattern on the surface of a molded product, and a mold base material formed on the inner surface of the concave portions. A molding die manufacturing method comprising a plating layer having fine irregularities finer than the uneven shape, wherein the plating layer is formed on both the protruding end surface of the convex portion and the inner surface of the concave portion. The inner surface of the concave portion of the mold base material on which the plating layer is formed is covered with a coating material that does not melt under reverse electrolytic treatment conditions, and the protruding end surface of the convex portion is exposed. The coating step and the metal base material whose inner surface of the concave portion is coated with the coating material are subjected to reverse electrolytic treatment to dissolve and remove the plating layer formed on the protruding end surface of the convex portion. In the plating layer removing step, the coating material is removed from the mold base material from which the plating layer formed on the protruding end surface of the convex portion has been removed, and the plating layer is selectively applied to the inner surface of the concave portion. A coating material removing step for obtaining the molding die in which the above-mentioned molding is formed is provided.

According to the molding die manufactured by such a molding die manufacturing method, when the valley portion is formed by the convex portion and the mountain portion is formed by the concave portion to form a grain pattern on the surface of the molded product, it is fine. The outer surface of the mountain portion can be roughened by the unevenness. Therefore, it is possible to reduce the contrast of the grain pattern while reducing the brightness and glossiness of the surface of the molded product, and it is possible to mold the molded product having excellent design.

The method for manufacturing a molding mold according to the third aspect is formed on a mold base material having convex portions and concave portions forming a concave-convex shape for forming a textured pattern on the surface of a molded product, and a protruding end surface of the convex portions. A first plating layer having a first unevenness finer than the uneven shape, and a second plating having a second unevenness finer than the uneven shape formed on the inner surface of the concave portion and having a roughness different from the first uneven shape. A method for manufacturing a molding mold comprising a layer, the second plating layer forming step of forming the second plating layer on both the protruding end surface of the convex portion and the inner surface of the concave portion, and the second plating. The inner surface of the concave portion of the mold base material on which the layer is formed is covered with a coating material that does not melt under the reverse electrolytic treatment condition and the first plating treatment condition, and the protruding end surface of the convex portion is exposed. The second plating layer formed on the protruding end surface of the convex portion by subjecting the metal base material having the inner surface of the concave portion coated with the coating material to the coating step in the state of being in the above state. The second plating layer removing step of melting and removing the metal base material and the metal base material from which the second plating layer formed on the protruding end face of the convex portion has been removed are subjected to the first plating treatment to perform the convexity. The first plating layer forming step of forming the first plating layer having a layer thickness different from that of the second plating layer on the protruding end surface of the portion, and the first plating layer being formed on the protruding end surface of the convex portion. By removing the coating material from the mold base material, the first plating layer is selectively formed on the protruding end surface of the convex portion, and the second plating layer is selectively formed on the inner surface of the concave portion. A coating material removing step for obtaining the formed molding die is provided.

The inventors of the present application have newly found that the roughness of fine irregularities can be changed by changing the layer thickness of the plating layer. Then, paying attention to the properties of such a plating layer, by making the layer thickness of the first plating layer different from the layer thickness of the second plating layer, the roughness of the first unevenness and the second unevenness is different. We have developed this technology. According to the molding die manufactured by such a molding die manufacturing method, when the valley portion is formed by the convex portion and the mountain portion is formed by the concave portion to form a grain pattern on the surface of the molded product, the first step is made. The bottom surface of the valley portion can be roughened by the first unevenness, and the outer surface of the mountain portion can be made a surface having a roughness different from the roughness of the bottom surface of the valley portion by the second unevenness. Therefore, the brightness and glossiness of the surface of the molded product can be reduced, and the contrast of the grain pattern can be appropriately adjusted to mold the molded product having excellent design.

According to the technique disclosed in the present specification, it is possible to provide a molding die capable of molding a molded product having excellent designability, a method for manufacturing an interior material for a vehicle, and a method for manufacturing a molding die.

Sectional drawing which shows the molding apparatus which concerns on Embodiment 1. Explanatory drawing which shows process of manufacturing a mold Laser micrograph showing the surface of the plating layer Top view of interior material for vehicles that schematically shows a grain pattern Cross-sectional view of interior material for vehicles that schematically shows a grain pattern Explanatory drawing which shows the process of manufacturing the molding mold which concerns on Embodiment 2. Top view of interior material for vehicles that schematically shows a grain pattern Cross-sectional view of interior material for vehicles that schematically shows a grain pattern Explanatory drawing which shows the process of manufacturing the molding mold which concerns on Embodiment 3. Top view of interior material for vehicles that schematically shows a grain pattern Cross-sectional view of interior material for vehicles that schematically shows a grain pattern Microscope photo showing the surface of the mold Chart showing measurement results and contrast evaluation regarding design

<Embodiment 1>
The first embodiment will be described with reference to FIGS. 1 to 5. In this embodiment, a molding apparatus 10 (see FIG. 1) for manufacturing an interior material 50 (molded product) for a vehicle is illustrated. The vehicle interior material 50 is made of, for example, a synthetic resin (for example, a thermoplastic resin such as polypropylene) and has a black color. Examples of the vehicle interior material 50 include a trim board (upper trim, lower trim, etc.) constituting a vehicle door trim.

As shown in FIG. 1, the molding apparatus 10 includes a pair of molding dies 11 and 20 provided so as to be openable and closable, and an injection apparatus 15. The molding die 11 has a molding surface 11A for molding the back surface of the vehicle interior material 50, and the molding die 20 has a molding surface for molding the design surface 51 (front surface) of the vehicle interior material 50. Has 20A. When the pair of molding dies 11 and 20 are closed, a molding space S1 that imitates the shape of the vehicle interior material 50 is formed between the molding surface 20A and the molding surface 11A arranged to face the molding surface 20A. Further, a runner 12 is provided inside the molding die 11, and the molten resin injected from the injection device 15 is supplied to the molding space S1 via the runner 12.

As shown in FIG. 2, the molding die 20 includes a mold base material 21 and a plating layer 30 laminated on the molding surface 21A of the mold base material 21. The mold base material 21 has, for example, a shape in which the molded surface 21A follows the outer shape of the vehicle interior material 50 by cutting a steel material containing iron as a main component and containing carbon, silicon, manganese, phosphorus, sulfur and the like. ing.

As shown in FIG. 2, the mold base material 21 has a convex portion 23A and a concave portion 23B that form a concave-convex shape 23 for forming a textured pattern 53 on the design surface 51 of the vehicle interior material 50. The molding surface 21A of the mold base material 21 may be further formed with another unevenness that is finer than the uneven shape 23 and coarser than the fine unevenness described later. As such another unevenness, a secondary grain in which a concave portion having a size smaller than that of the convex portion 23A and the concave portion 23B is formed by the same forming method as the uneven shape 23, or an uneven shape having a different forming method from the uneven shape 23, etc. There may be. As another unevenness having a different forming method from the uneven shape 23, for example, one formed by sandblasting or electrolytic etching can be exemplified. Another unevenness formed by electrolytic etching can have a concave diameter of, for example, 10 μm or more. In FIG. 2, the illustration of such another unevenness is omitted, and only the uneven shape 23 of the mold base material 21 is schematically drawn.

The uneven shape 23 is formed by chemical etching in the grain pattern forming step described later. In the recess 23B, the height dimension of the mountain portion 53B transferred to the design surface 51 is about 100 μm to 200 μm, and the lengths of the adjacent two sides BR1 and BR2 of the circumscribed rectangle are in the range of 1000 μm to 4000 μm, respectively. It is formed (see FIGS. 4 and 5). The convex portion 23A is formed so as to extend to the ridge between the adjacent concave portions 23B. The uneven shape 23 can form a complicated grain pattern 53 by making the lengths and combinations of the adjacent two sides BR1 and BR2 of the circumscribed rectangles of the mountain portion 53B different.

The plating layer 30 is made of chrome plating and is formed by a plating layer forming step described later. In the present embodiment, the plating layer 30 is a plating layer selectively formed on the protruding end surface 24 of the convex portion 23A and having finer unevenness than the uneven shape 23. In FIG. 2, the plating layer 30 is schematically drawn as a flat layer, but the plating layer 30 has fine irregularities in the shape of a fluff as seen in the laser micrograph of FIG.

As shown in FIG. 2, the plating layer 30 is formed only on the protruding end surface 24 of the convex portion 23A, and is not formed on the inner surface 25 of the concave portion 23B. In this embodiment, the mold base material 21 is exposed to the outside on the inner surface 25 of the recess 23B. When the surface of the mold base material 21 is a smooth surface, the region where the plating layer 30 is formed in the molding die 20 has a surface roughness equivalent to that of fine irregularities, and the inner surface 25 of the smooth recess 23B has a smooth surface. It will be roughened as compared to. When the surface of the mold base material 21 is a surface having another unevenness finer than the uneven shape 23, the region where the plating layer 30 is formed in the molding die 20 is fine on the surface of such another unevenness. By adding the unevenness, the surface has a complicated and fine uneven shape as compared with the inner surface 25 of the concave portion 23B.

The plating layer 30 is formed so as to have fine irregularities having an average protrusion diameter of 0.1 μm to 2.0 μm. The "average protrusion diameter" is obtained by observing the surface of the plating layer 30 formed on a flat test piece at a magnification of 9000 using a laser microscope and calculating the average value of the diameters of about 100 protrusions (the average protrusion diameter). See Figure 3). As a result of diligent research, the inventors of the present application have a correlation between the average protrusion diameter of fine irregularities and the design of the vehicle interior material 50, and the molding die 20 provided with the plating layer 30 having such fine irregularities is used. For example, it was found that the effect of improving the design of the vehicle interior material 50 can be obtained. The fine unevenness is made finer than the uneven shape 23 for forming the grain pattern 53 of the mold base material 21. In the present embodiment, the fine unevenness is made finer than another unevenness (secondary grain, unevenness formed by sandblasting or electrolytic etching) formed on the mold base material 21.

The plating layer 30 is formed so that the arithmetic mean roughness Ra of the surface having fine irregularities is within the range of 0.2 μm or more and 1.0 μm or less. The measurement of "arithmetic mean roughness Ra of a surface having fine irregularities" was performed using a plating layer 30 formed on a flat test piece in order to avoid the influence of the irregular shape 23 and the like. When the arithmetic mean roughness Ra is 0.2 μm or more, the surface can be made rougher than the so-called glossy plating layer, which is preferable. If the arithmetic mean roughness Ra is 1.0 μm or less, it is finer than, for example, the uneven shape 23 that can be formed by chemical etching or another unevenness (secondary grain, unevenness formed by sandblasting or electrolytic etching). It is preferable because it can have various irregularities.

The plating layer 30 has a layer thickness of 5 μm or more and 20 μm or less. As a result of diligent research, the inventors of the present application have found that fine irregularities can be suitably formed on the plating layer according to such a layer thickness. Further, the layer thickness of the plating layer 30 is preferably 10 μm or more and 20 μm or less, and particularly preferably about 15 μm in order to form fine irregularities.

Subsequently, a method for manufacturing the molding die 20 will be described with reference to FIG. 2. The method for manufacturing the mold 20 includes a coating step of coating the mold base material 21 with the coating material 60, a plating layer forming step of forming the plating layer 30, and a coating material for removing the coating material 60 from the mold base material 21. It has a removal process. Each step is sequentially performed in this order, and another step such as a washing step or a drying step may be appropriately performed between the steps. In the manufacturing method of the molding die 20, a grain pattern forming step is performed prior to the coating step.

In the grain pattern forming step, the uneven shape 23 is formed by an etching process. The etching treatment is performed using an acidic solution (for example, nitric acid) that corrodes the metal constituting the mold base material 21 and an acid-resistant ink that blocks this solution. First, after cleaning the mold base material 21, the surfaces other than the molding surface 21A are masked with tape or the like. Subsequently, the grain pattern 53 is transferred to the molding surface 21A of the mold base material 21 with the acid-resistant ink. The molded surface is then corroded with an acidic solution. Then, the portion covered with the acid-resistant ink is not corroded and becomes the remaining convex portion 23A, and the uncovered portion is corroded to become the concave portion 23B. As a result, the uneven shape 23 is formed on the molding surface 21A of the mold base material 21.

In the coating step, the inner surface 25 of the concave portion 23B is covered with a coating material 60 that does not melt under the plating treatment conditions described later, and the protruding end surface 24 of the convex portion 23A is exposed. As the coating material 60, a wax having an insulating property having a melting point of about 50 to 90 ° C. or the like can be preferably used. First, the molten coating material 60 is applied to the surface of the mold base material 21 having the uneven shape 23. At this time, the coating material 60 is filled in the recess 23B. Then, after the coating material 60 is solidified, the coating material 60 applied to the protruding end surface 24 of the convex portion 23A is removed. The unnecessary covering material 60 is removed by, for example, using a rubber type scraper 61 or the like that is softer than the hardness of the mold base material 21 to grind the covering material 60 deposited on the protruding end surface 24 of the convex portion 23A. ..

In the plating layer forming step, the mold base material 21 whose inner surface 25 of the recess 23B is covered with the coating material 60 is plated to form the plating layer 30 on the protruding end surface 24 of the convex portion 23A. First, the mold base material 21 coated with the coating material 60 is immersed in a plating bath 70 (chromium plating bath, Sargent bath) containing chromic acid and sulfuric acid as main components, and connected to a power source. Then, by using the mold base material 21 as the negative electrode and the electrode as the positive electrode, electroplating is performed on the mold base material 21. As a result, the chromium ions in the plating bath 70 are reduced and deposited as the plating layer 30 on the protruding end face 24 of the convex portion 23A of the mold base material 21. Here, the plating process is performed until the thickness of the plating layer reaches the above-mentioned thickness under the condition that fine irregularities are formed. At this time, the plating treatment conditions can be, for example, a bath temperature of 37 ° C. and a current density of 60 A / dm ² .

In the coating material removing step, the coating material 60 is removed from the mold base material 21 in which the plating layer 30 is formed on the protruding end surface 24 of the convex portion 23A, and the plating layer 30 is selectively formed on the protruding end surface 24 of the convex portion 23A. The formed mold 20 is obtained. Specifically, a method of applying high-pressure steam to the molding surface 21A of the mold base material 21 to dissolve the covering material 60 filled inside the recess 23B and removing it from the recess 23B, or a method of removing the mold base material 21 from the inside of the recess 23B. The coating material 60 can be removed from the mold base material 21 by immersing the coating material 60 in boiled water, dissolving the coating material 60, and pouring the coating material 60 having a specific gravity smaller than that of water out of the recess 23B.

Subsequently, a method of manufacturing the interior material 50 for a vehicle will be described. The method for manufacturing the vehicle interior material 50 includes a molding step of injection molding the vehicle interior material 50 using the molding apparatus 10 (molding mold 20). First, as shown in FIG. 1, the pair of molding dies 11 and 20 are closed. As a result, a molding space S1 that follows the shape of the vehicle interior material 50 is formed between the molding surface 20A and the molding surface 11A. Next, the black molten resin is injected from the injection device 15 into the molding space S1 through the runner 12. After that, the molten resin filled in the molding space S1 is cooled, so that the vehicle interior material 50 is molded.

In the molding step, the valley portion 53A is formed by the convex portion 23A and the mountain portion 53B is formed by the concave portion 23B to form a grain pattern 53 on the design surface 51 of the vehicle interior material 50, and the valley portion 53A is formed by fine unevenness. The bottom surface 54 is roughened. In other words, in the molding process, the textured pattern 53 is formed on the design surface 51 of the vehicle interior material 50 by transferring the uneven shape 23, and the bottom surface 54 of the valley portion 53A is formed by transferring the fine uneven shape. The surface is rougher than the outer surface 55 of the portion 53B. Further, the shape to which the shape of the fine unevenness is transferred is schematically drawn by a plurality of circles in FIG. 4, and is schematically drawn in a plurality of dome shapes in FIG. After that, the pair of molding dies 11 and 20 are opened, and the vehicle interior material 50 is removed. This completes the production of the vehicle interior material 50.

Subsequently, the effect of this embodiment will be described. According to the present embodiment, when the valley portion 53A is formed by the convex portion 23A and the mountain portion 53B is formed by the concave portion 23B to form the grain pattern 53 on the design surface 51 of the vehicle interior material 50, the valley portion is formed. The bottom surface 54 of 53A can be roughened. Therefore, it is possible to increase the contrast of the grain pattern 53 while reducing the brightness and glossiness of the design surface 51 of the vehicle interior material 50, and it is possible to mold the vehicle interior material 50 having excellent design. ..

Further, in the present embodiment, the plating layer 30 has fine irregularities having an average protrusion diameter of 0.1 μm to 2.0 μm. Therefore, the brightness and glossiness of the design surface 51 of the vehicle interior material 50 can be suitably reduced.

<Embodiment 2>
Next, the second embodiment will be described with reference to FIGS. 6 to 8. In the present embodiment, a molding die 120 having a plating layer 130 having fine irregularities finer than the concave-convex shape 23, which is selectively formed on the inner surface 25 of the concave portion 23B, is exemplified. It should be noted that overlapping description of the same configuration, operation and effect as in the above-described embodiment will be omitted.

As shown in FIG. 6, the plating layer 130 is formed only on the inner surface 25 of the concave portion 23B, and is not formed on the protruding end surface 24 of the convex portion 23A. In this embodiment, the mold base material 21 is exposed to the outside on the protruding end surface 24 of the convex portion 23A. When the surface of the mold base material 21 is a smooth surface, the region where the plating layer 130 is formed in the molding die 120 has a surface roughness equivalent to that of fine irregularities, and the protrusion of the smooth convex portion 23A. The surface is roughened as compared with the end surface 24. When the surface of the mold base material 21 is a surface having finer irregularities than the uneven shape 23, the region where the plating layer 130 is formed in the molding die 120 is imparted with fine irregularities on the surface of such fine irregularities. As a result, the surface has a complicated and fine uneven shape as compared with the protruding end surface 24 of the convex portion 23A. The properties of the plating layer 130 are the same as those of the plating layer 130 of the first embodiment, and the description thereof will be omitted.

Subsequently, a method for manufacturing the molding die 120 will be described. The manufacturing method of the mold 120 includes a plating layer forming step of forming the plating layer 130, a coating step of covering the mold base material 21 with the covering material 60, and a plating layer 130 formed on the protruding end surface 24 of the convex portion 23A. It is provided with a plating layer removing step of dissolving and removing the coating material, and a coating material removing step of removing the coating material 60 from the mold base material 21. Each step is sequentially performed in this order, and another step such as a washing step or a drying step may be appropriately performed between the steps. In the manufacturing method of the molding die 120, the same grain pattern forming step as in the first embodiment is performed prior to the plating layer forming step.

In the plating layer forming step, the plating layer 130 is formed on both the protruding end surface 24 of the convex portion 23A and the inner surface 25 of the concave portion 23B. The plating treatment conditions are the same as those in the plating layer forming step of the first embodiment, and the description thereof will be omitted.

In the coating step, the inner surface 25 of the recess 23B of the mold base material 21 on which the plating layer 130 is formed is coated with the coating material 60 that does not melt under the reverse electrolytic treatment conditions, and the protruding end surface 24 of the convex portion 23A is exposed. Make it a state. The covering material 60 and its covering mode are the same as those in the first embodiment, and the description thereof will be omitted.

In the plating layer removing step, the mold base material 21 whose inner surface 25 of the concave portion 23B is covered with the coating material is subjected to reverse electrolysis treatment to dissolve the plating layer 130 formed on the protruding end surface 24 of the convex portion 23A. Remove. First, the mold base material 21 coated with the coating material 60 is immersed in a plating bath 70 (chromium plating bath, Sargent bath) containing chromic acid and sulfuric acid as main components as in the first embodiment, and connected to a power source. Then, by using the mold base material 21 as the positive electrode and the electrode as the negative electrode, the plating layer 130 laminated on the protruding end surface 24 of the convex portion 23A of the mold base material 21 is electrolytically peeled off. As a result, the plating layer 130 formed on the protruding end surface 24 of the convex portion 23A is selectively peeled off while the plating layer 130 formed on the inner surface 25 of the concave portion 23B remains.

In the coating material removing step, the coating material 60 is removed from the mold base material 21 from which the plating layer 130 formed on the protruding end surface 24 of the convex portion 23A has been removed, and the plating layer 130 is selectively formed on the inner surface 25 of the concave portion 23B. A molding die 120 in which the above is formed is obtained. The removal mode of the covering material 60 is the same as that of the covering material removing step of the first embodiment, and the description thereof will be omitted.

Subsequently, a method for manufacturing the interior material 150 for a vehicle will be described. The method for manufacturing the vehicle interior material 150 includes a molding step of injection molding the vehicle interior material 150 using the molding apparatus 10 (molding mold 120). In the molding process, the valley portion 53A is formed by the convex portion 23A and the mountain portion 53B is formed by the concave portion 23B to form a grain pattern 53 on the design surface 51 of the vehicle interior material 150, and the mountain portion 53B is formed by fine unevenness. The outer surface 155 is roughened. In other words, in the molding process, the textured pattern 53 is formed on the design surface 51 of the vehicle interior material 50 by transferring the uneven shape 23, and the protruding end surface 153 of the mountain portion 53B is transferred by transferring the fine uneven shape. The surface is rougher than the bottom surface 154 of the valley portion 53A. In addition, the shape to which the shape of the fine unevenness is transferred is schematically drawn by a plurality of circles in FIG. 7, and is schematically drawn in a plurality of dome shapes in FIG.

Subsequently, the effect of this embodiment will be described. According to the present embodiment, when the valley portion 53A is formed by the convex portion 23A and the mountain portion 53B is formed by the concave portion 23B to form the grain pattern 53 on the design surface 51 of the vehicle interior material 150, the mountain portion is formed. The outer surface 155 of 53B can be roughened. Therefore, it is possible to reduce the contrast of the grain pattern 53 while reducing the brightness and glossiness of the design surface 51 of the vehicle interior material 150, and it is possible to mold the vehicle interior material 150 having excellent design. ..

<Embodiment 3>
Next, the third embodiment will be described with reference to FIGS. 9 to 11. In the present embodiment, the first plating layer 30 having the first unevenness finer than the uneven shape 23 formed on the protruding end surface 24 of the convex portion 23A and the uneven shape 23 formed on the inner surface 25 of the concave portion 23B are finer and finer. An example is a molding mold 220 including a second plating layer 40 having a second unevenness having a roughness different from that of the first unevenness. It should be noted that overlapping description of the same configuration, operation and effect as in the above-described embodiment will be omitted.

The first plating layer 30 has the same structure as the plating layer 30 of the first embodiment, and the first unevenness corresponds to the above-mentioned fine unevenness. The second plating layer 40 is made of chrome plating and has a second unevenness that is coarser than the first unevenness. When the surface of the mold base material 21 is a smooth surface, the region where the first plating layer 30 is formed in the mold 220 has the same surface roughness as the first unevenness, and the mold 220 has the same surface roughness. The region where the second plating layer 40 is formed has a surface roughness equivalent to that of the second unevenness. When the surface of the mold base material 21 is a surface having finer irregularities than the uneven shape 23, the region where the first plating layer 30 is formed in the molding die 220 is first on the surface of such fine irregularities. The surface having a complicated and fine uneven shape with irregularities is formed, and the region where the second plating layer 40 is formed in the molding die 220 is a complex having the second irregularities imparted to the surface of such fine irregularities. The surface has an uneven shape. The properties of the first plating layer 30 are the same as those of the plating layer 30 of the first embodiment, and the description thereof will be omitted.

The second plating layer 40 has a layer thickness larger than that of the first plating layer 30. As a result of diligent research, the inventors of the present application have determined the layer thickness of the plating layer and the interior material for vehicles under conditions where a plating layer having fine irregularities (corresponding to the first plating layer 30 of the present embodiment) can be formed. It was found that there is a correlation with the design of 250, and that the larger the layer thickness, the higher the brightness and gloss value of the vehicle interior material 250 tend to be. Then, by making the layer thickness of the second plating layer 40 larger than that of the first plating layer 30, the brightness and gloss value of the outer surface 255 of the mountain portion 53B in the grain pattern 53 are set to the brightness of the bottom surface 254 of the valley portion 53A. And it was found that the contrast of the grain pattern 53 can be appropriately adjusted by making it higher than the gloss value.

Subsequently, a method for manufacturing the molding die 220 will be described. The manufacturing method of the mold 220 is formed on a second plating layer forming step of forming the second plating layer 40, a covering step of covering the mold base material 21 with the covering material 60, and a protruding end face 24 of the convex portion 23A. A second plating layer removing step of melting and removing the second plating layer 40, a first plating layer forming step of forming the first plating layer 30, and a coating for removing the coating material 60 from the mold base material 21. It is equipped with a material removal process. Each step is sequentially performed in this order, and another step such as a washing step or a drying step may be appropriately performed between the steps. In the manufacturing method of the molding die 220, the same grain pattern forming step as in the first embodiment is performed prior to the second plating layer forming step.

In the second plating layer forming step, the second plating layer 40 is formed on both the protruding end surface 24 of the convex portion 23A and the inner surface 25 of the concave portion 23B. In the present embodiment, the plating bath 70 similar to the plating layer forming step of the first embodiment is used, and the second plating is different from the plating treatment conditions (first plating treatment conditions) of the plating layer forming step of the first embodiment. Plating is performed under the processing conditions. Here, as the second plating treatment condition, the plating treatment condition is such that the average protrusion diameter of the protrusions on the surface of the plating layer is larger than that of the first plating layer 30 and the second unevenness is formed coarser than the first unevenness. Let's take the case of this as an example.

In the coating step, the inner surface 25 of the recess 23B of the mold base material 21 on which the second plating layer 40 is formed is coated with the coating material 60 that does not melt under the reverse electrolysis treatment conditions and the first plating treatment conditions, and is also covered. It is assumed that the protruding end surface 24 of the convex portion 23A is exposed. The covering material 60 and its covering mode are the same as those in the first embodiment, and the description thereof will be omitted.

In the second plating layer removing step, the second plating layer 40 formed on the protruding end surface 24 of the convex portion 23A by subjecting the mold base material 21 whose inner surface 25 of the concave portion 23B is covered with the covering material 60 to a reverse electrolysis treatment. Dissolve and remove. The embodiment for removing the second plating layer 40 is the same as the plating layer removing step of the second embodiment, and the description thereof will be omitted.

In the first plating layer forming step, the mold base material 21 from which the second plating layer 40 formed on the protruding end surface 24 of the convex portion 23A has been removed is subjected to the first plating treatment, and the protruding end surface 24 of the convex portion 23A is applied. The first plating layer 30 having a layer thickness different from that of the second plating layer 40 is formed. In the present embodiment, the first plating layer 30 having a layer thickness smaller than that of the second plating layer 40 is formed. The embodiment of forming the first plating layer 30 is the same as the plating layer forming step of the first embodiment, and the description thereof will be omitted.

In the coating material removing step, the coating material 60 is removed from the mold base material 21 in which the first plating layer 30 is formed on the protruding end surface 24 of the convex portion 23A, and the first is selectively selected on the protruding end surface 24 of the convex portion 23A. A mold 220 is obtained in which the plating layer 30 is formed and the second plating layer 40 is selectively formed on the inner surface 25 of the recess 23B. The removal mode of the covering material 60 is the same as that of the covering material removing step of the first embodiment, and the description thereof will be omitted.

Subsequently, a method for manufacturing the interior material 250 for vehicles will be described. The method for manufacturing the vehicle interior material 250 includes a molding step of injection molding the vehicle interior material 250 using the molding apparatus 10 (molding mold 220). In the molding step, the valley portion 53A is formed by the convex portion 23A and the mountain portion 53B is formed by the concave portion 23B to form a grain pattern 53 on the design surface 51 of the vehicle interior material 250, and the valley portion 53A is formed by the first unevenness. The bottom surface 254 of the above is roughened, and the outer surface 255 of the mountain portion 53B is roughened with a roughness different from that of the bottom surface 254 of the valley portion 53A. In other words, in the molding process, the textured pattern 53 is formed on the design surface 51 of the vehicle interior material 250 by transferring the uneven shape 23, and the valley portion is transferred by transferring the shapes of the first unevenness and the second unevenness. It is assumed that the bottom surface 254 of the 53A and the outer surface 255 of the mountain portion 53B are given uneven shapes with different roughness. In the present embodiment, the bottom surface 254 of the valley portion 53A is provided with a finer uneven shape than the outer surface 255 of the mountain portion 53B. In FIG. 10, the shape to which the shape of the first unevenness is transferred is schematically drawn by a plurality of small diameter circles, and the shape to which the shape of the second unevenness is transferred is schematically drawn by a plurality of large diameter circles. I'm drawing. Further, in FIG. 11, the shape to which the shape of the first unevenness is transferred is schematically drawn into a dome shape having a plurality of small diameters, and the shape to which the shape of the second unevenness is transferred is schematically drawn into a dome having a plurality of large diameters. It is drawn in a shape.

Subsequently, the effect of this embodiment will be described. The inventors of the present application have newly found that the roughness of fine irregularities can be changed by changing the layer thickness of the plating layer. Then, paying attention to the properties of such a plating layer, the roughness of the first unevenness and the second unevenness is different by making the layer thickness of the first plating layer 30 and the layer thickness of the second plating layer 40 different. We have developed the technology of this embodiment. According to the molding die manufactured by such a molding die 220 manufacturing method, the valley portion 53A is formed by the convex portion 23A and the mountain portion 53B is formed by the concave portion 23B, and the design surface 51 of the vehicle interior material 250 is formed. When the grain pattern 53 is formed, the bottom surface 254 of the valley portion 53A is roughened by the first unevenness, and the outer surface 255 of the mountain portion 53B is roughened by the second unevenness, which is different from the roughness of the bottom surface 254 of the valley portion 53A. It can be the face of the mountain. Therefore, the brightness and glossiness of the design surface 51 of the vehicle interior material 250 can be reduced, and the contrast of the grain pattern 53 is appropriately adjusted to form the vehicle interior material 250 having excellent design. Can be done.

<Example>
Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples as long as the gist of the present invention is not exceeded.

First, the molding dies and molded products of Examples and Comparative Examples were prepared as follows. The molding die of the first embodiment corresponds to a flat plate of the same material as the mold base material having an uneven shape for forming a grain pattern, and a plating layer 30 on the protruding end face of the convex portion by the method described in the first embodiment. A plating layer was formed. In the molding die of Example 2, a plating layer corresponding to the plating layer 130 was formed on the inner surface of the recess by the method described in the second embodiment on the same flat plate. In the molding die of Example 3, a plating layer corresponding to the first plating layer 30 is formed on the protruding end surface of the convex portion on the same flat plate by the method described in the third embodiment, and the second plating layer is formed on the inner surface of the concave portion. A plating layer corresponding to 40 was formed. In the molding die of Comparative Example 1, a plating layer corresponding to the plating layer 30 was formed on the entire surface of the same flat plate (both the protruding end surface of the convex portion and the inner surface of the concave portion). The molding die of Comparative Example 2 was a flat plate made of the same material as the mold base material having an uneven shape. Then, using each of the above-mentioned molding dies, a black molded product was injection-molded.

The surfaces of the molds of Example 1, Example 2, and Comparative Example 1 were observed at 100 times using a microscope. A photograph of the microscope is shown in FIG.

In addition, the brightness and glossiness of the molded products molded using the molding dies of each Example and each Comparative Example were measured as follows, and the contrast of the grain pattern was evaluated from the following viewpoints. .. The results are shown in the table of FIG.
Lightness (L *): The lightness (brightness in the L * a * b * color system) was measured by a spectrocolorimeter (CM-700d, manufactured by Konica Minolta).
Glossiness: A 60-degree gloss value was measured with a gloss meter (all-in-one gloss meter IQ, manufactured by RHOPOINT INSTRUMENTS).
Contrast: The design surface of the molded product was visually observed, and the contrast between the peaks and valleys of the grain pattern was evaluated based on the appearance of the grain pattern in Comparative Example 2. In the table of FIG. 13, "high" indicates that the contrast is high (for example, the grain pattern is easy to see and has a sense of depth) with respect to Comparative Example 2, and "medium" is based on Comparative Example 2. "Low" indicates that the contrast is the same, and "low" indicates that the contrast is low (for example, the grain pattern is difficult to see and there is no sense of depth) with reference to Comparative Example 2.

As shown in FIG. 12, as a result of observation with a microscope, in the first embodiment, the protruding end surface of the convex portion extending to the ridge is visually recognized as a dark portion as compared with the inner surface of the concave portion, and is selectively selected as the protruding end surface of the convex portion. It was confirmed that a plating layer was formed on the surface. In Example 2, the protruding end surface of the convex portion extending to the ridge was visually recognized as whitish as compared with the inner surface of the concave portion, and it was confirmed that the plating layer was selectively formed on the inner surface of the concave portion. In Comparative Example 1, it was confirmed that there was not much difference in brightness between the convex portion and the concave portion, and that the plating layer was uniformly formed on the entire surface of the molding die.

As shown in the table of FIG. 13, the molded products of Example 1 and Example 2 have lower brightness and glossiness as compared with Comparative Example 2 in which the plating layer having fine irregularities is not formed. .. In particular, the glossiness of the molded products of Examples 1 and 2 is 1.1, which is higher than that of Comparative Example 1 (glossiness = 0.9), but is similar to that of Comparative Example 2 (glossiness = 1.3). It is low compared to general molded products. From this, it was found that the effect of sufficiently reducing the glossiness can be obtained only by forming a plating layer having fine irregularities on either the protruding end surface of the convex portion or the inner surface of the concave portion. The molded products of Examples 1 and 2 had good designability from the viewpoint of low gloss and jet blackness.

As shown in the table of FIG. 13, when the plating layer is formed on the entire surface of the molding die as in Comparative Example 1, the contrast of the grain pattern is lower than that of Comparative Example 2. On the other hand, in Example 1, the contrast of the grain pattern is higher than that of Comparative Example 2 by forming the plating layer only on the protruding end surface of the convex portion. The design of the molded product of Example 1 was a design in which the grain pattern was conspicuous. Further, in Example 2, by forming the plating layer only on the inner surface of the recess, the contrast of the grain pattern is lower than that in Comparative Example 2. The design of the molded product of Example 2 had a matte impression in which the grain pattern was inconspicuous. Further, in Example 2, although the contrast of the grain pattern was lowered as in Comparative Example 1, the view of the grain pattern of the molded product, for example, the view of the valley portion with respect to the line of sight from an oblique direction, was compared with Comparative Example 2. It is considered to be useful from the viewpoint of realizing the grain pattern of various designs. In Example 3, by forming the first plating layer and the second plating layer, it is possible to realize the same textured contrast as in Comparative Example 2. That is, in Example 1, Example 2, and Example 3, the contrast of the grain pattern is appropriately adjusted by selectively forming a plating layer on one of the protruding end surface of the convex portion and the inner surface of the concave portion. It has been found that a molded product exhibiting a desired design can be formed.

<Other embodiments>
The present invention is not limited to the embodiments described above and the drawings, and for example, the following embodiments are also included in the technical scope of the present invention.
(1) In the above embodiment, an injection molding die is exemplified as a molding die, but the present invention is not limited to this. The molding die may be any as long as it is used in a molding method in which the shape of the molded surface is transferred to the surface of the molded product, and examples thereof include a press molding die used for press molding and a vacuum forming die used for vacuum forming.
(2) In the above embodiment, an example in which the plating layer is chromium is exemplified, but the present invention is not limited to this. For example, the plating layer may be composed of a metal other than chromium (nickel, copper, etc.).
(3) In the above embodiment, the interior material for a vehicle is exemplified as a molded product, but the molded product is not limited to this. Further, the upper trim and the lower trim are exemplified as the interior material for the vehicle, but the present invention is not limited thereto. The interior material for a vehicle may be a member provided on the vehicle and having a design surface, and examples thereof include a skin material made of synthetic resin (for example, an olefin-based thermoplastic elastomer), an instrument panel, an assist grip, and the like. be able to. Further, the interior material for a vehicle may be composed of a plurality of layers.
(4) In the above embodiment, a vehicle interior material exhibiting black color is exemplified, but the color of the vehicle interior material is not limited to black. Even when applied to a vehicle interior material exhibiting a color other than black, its brightness and glossiness can be lowered.
(5) In the above embodiment, a configuration in which a concave-convex shape and fine irregularities are formed on the molded surface is exemplified, but the present invention is not limited to this. For example, any or all of the above-mentioned three types of other irregularities may be further formed. Further, the method of forming the uneven shape for forming the grain pattern can be appropriately changed, and may be formed by, for example, laser processing.
(6) The structure of the plating bath is not limited to that described above. As the plating bath, a chromic acid bath containing chromic acid, sulfuric acid, and silicic acid as main components may be used.
(7) The molding die may be manufactured by a manufacturing method other than the above-described embodiment. For example, the plating layer formed on the protruding end face may be peeled off with hydrochloric acid or the like to manufacture a molding die.

(8) In the third embodiment, the first plating layer has the same structure as the plating layer of the first embodiment, and the second plating layer has a structure having a second unevenness coarser than the first unevenness. However, it is not limited to this. For example, the second plating layer may have the same structure as the plating layer of the first embodiment, and the first plating layer may have a structure having the first unevenness coarser than the second unevenness. Further, the first plating layer and the second plating layer may be composed of different types of metal plating.

20, 120, 220 ... Molding mold, 21 ... Mold base material, 23 ... Concavo-convex shape, 23A ... Convex part, 23B ... Concave part, 24 ... Protruding end face, 25 ... Inner surface, 30, 130 ... Plating layer, First plating layer , 40 ... 2nd plating layer, 50, 150, 250 ... Vehicle interior material (molded product), 51 ... Design surface (surface), 53,153,253 ... Texture pattern, 53A ... Tanibe, 53B ... Yamabe, 54, 154, 254 ... bottom surface, 55 ... outer surface, 60 ... coating material

Claims (5)

It is a method of manufacturing an interior material for a vehicle, in which an interior material for a vehicle is molded using a molding die.
The molding mold is
A mold base material having convex portions and concave portions forming an uneven shape for forming a grain pattern on the surface of a molded product, and a mold base material.
A plating layer having fine irregularities finer than the uneven shape, which is selectively formed on one of the protruding end surface of the convex portion and the inner surface of the concave portion, is provided .
The valley portion is formed by the convex portion and the mountain portion is formed by the concave portion to form the grain pattern on the design surface of the vehicle interior material.
When the plating layer is formed on the protruding end surface of the convex portion, the bottom surface of the valley portion is roughened by the fine unevenness.
A method for manufacturing an interior material for a vehicle, in which when the plating layer is formed on the inner surface of the concave portion, the outer surface of the mountain portion is roughened by the fine unevenness. The method for manufacturing an interior material for a vehicle according to claim 1, wherein the plating layer has the fine irregularities having an average protrusion diameter of 0.1 μm to 2.0 μm. A mold base material having convex portions and concave portions forming an uneven shape for forming a textured pattern on the surface of a molded product, and fine irregularities formed on the protruding end surface of the convex portion, which are finer than the uneven shape. It is a manufacturing method of a molding die including a plating layer having a plating layer.
A coating step of covering the inner surface of the concave portion with a coating material that does not melt under plating treatment conditions and exposing the protruding end surface of the convex portion.
A plating layer forming step of forming the plating layer on the protruding end surface of the convex portion by subjecting the mold base material whose inner surface of the concave portion is coated with the coating material to a plating treatment.
The molding die in which the coating material is removed from the mold base material on which the plating layer is formed on the protruding end surface of the convex portion, and the plating layer is selectively formed on the protruding end surface of the convex portion. A method of manufacturing a molding die comprising a coating material removing step and a method for obtaining a coating material. A mold base material having convex portions and concave portions forming an uneven shape for forming a textured pattern on the surface of a molded product, and plating having fine irregularities formed on the inner surface of the concave portions and having finer irregularities than the uneven shape. A method of manufacturing a molding die comprising a layer.
A plating layer forming step of forming the plating layer on both the protruding end surface of the convex portion and the inner surface of the concave portion,
A coating step in which the inner surface of the concave portion of the mold base material on which the plating layer is formed is covered with a coating material that does not melt under reverse electrolysis treatment conditions, and the protruding end surface of the convex portion is exposed. When,
Removal of the plating layer by subjecting the mold base material whose inner surface of the concave portion is covered with the coating material to a reverse electrolysis treatment to dissolve and remove the plating layer formed on the protruding end surface of the convex portion. Process and
The molding in which the coating material is removed from the mold base material from which the plating layer formed on the protruding end surface of the convex portion has been removed, and the plating layer is selectively formed on the inner surface of the concave portion. A method for manufacturing a mold, comprising a step of removing a coating material to obtain a mold. A mold base material having convex portions and concave portions forming an uneven shape for forming a textured pattern on the surface of a molded product, and first unevenness finer than the uneven shape formed on the protruding end surface of the convex portion. A molding mold manufacturing method comprising a first plating layer having a first plating layer and a second plating layer having a second unevenness having a roughness different from that of the first unevenness, which is finer than the uneven shape formed on the inner surface of the concave portion. There,
A second plating layer forming step of forming the second plating layer on both the protruding end surface of the convex portion and the inner surface of the concave portion.
The inner surface of the concave portion of the mold base material on which the second plating layer is formed is covered with a coating material that does not melt under the reverse electrolysis treatment condition and the first plating treatment condition, and the convex portion is said. The coating process that leaves the protruding end face exposed, and
The mold base material whose inner surface is coated with the coating material is subjected to reverse electrolysis treatment to dissolve and remove the second plating layer formed on the protruding end surface of the convex portion. 2 Plating layer removal process and
The mold base material from which the second plating layer formed on the protruding end surface of the convex portion has been removed is subjected to the first plating treatment, and the protruding end surface of the convex portion is referred to as the second plating layer. A first plating layer forming step for forming the first plating layer having a different layer thickness,
The coating material is removed from the mold base material on which the first plating layer is formed on the protruding end surface of the convex portion, and the first plating layer is selectively formed on the protruding end surface of the convex portion. A method for manufacturing a molding die, comprising a step of removing a coating material to obtain the molding die in which the second plating layer is selectively formed on the inner surface of the recess.

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