Decorated-part having a fine decoration using a laser processed groove

Abstract

A method for manufacturing a decorated-part comprises a first and second base coat-layer-forming process, a surface coat-layer-forming process and a laser-decorating process. In the first base coat-layer-forming process, the first base coat-layer colored in a highly light color at a lightness-level of 70 or more is formed on the surface of the resin base-material 12. In the second base coat-layer-forming process, the second base coat-layer 21C colored in a chromatic color is formed on the first base coat-layer. In the surface coat-layer-forming process, the surface coat-layer colored in a less-bright color at a lightness-level of 20 or less is formed on the second base coat-layer 21C. In the laser-decorating process, the first laser-processed groove penetrating the surface coat-layer and exposing partially the second base coat-layer is made by irradiating the infrared laser onto such surface coat-layer, thus providing a fine decoration onto the surface of said decorated-part.

Claims

1. A decorated-part of which a fine decoration is provided on a surface of the decorated-part by a laser-processed groove, the decorated part comprising: a resin base-material; the first base coat-layer formed on a surface of the resin base-material; at least one second base coat-layer formed on a surface of the first base coat-layer; and a surface coat-layer formed on the second base coat-layer, a thickness of the surface coat-layer being greater than a thickness of the second base coat-layer; and further characterized in comprising a first laser-processed groove that goes through the surface coat-layer and partially exposes the second base coat-layer but does not expose the first base coat-layer, and a second laser-processed groove, which has a groove depth less than a groove depth of the first laser-processed groove, the second laser-processed groove not penetrating the surface coat-layer, the surface coat-layer, including the second laser-processed groove, being a single layer colored in black, an entire top surface of the surface coat-layer being totally visible; the first base coat-layer being colored in white, invisible, and having no surface design; and the second base coat-layer being colored in a chromatic color brighter than the color of the surface coat-layer, a top surface of the second base coat layer being partially visible; wherein a roughness (Ra) of the exposed area, which is at a bottom of the first laser-processed groove of the second base coat-layer, is 2 μm or less, wherein the surface coat layer further comprises: a plurality of first drawn patterns of rectangular shape; and a plurality of second drawn patterns of rectangular shape; each of the first drawn patterns including the second laser processed grooves, the second laser processed grooves drawn in parallel and extending obliquely upward to the right in plan view for each of the first drawn patterns; each of the second drawn patterns including the second laser processed grooves, the second laser processed grooves drawn in parallel and extending obliquely upward to the left in plan view for each of the second drawn patterns; the first and second drawn patterns adjacent to each other on the surface coat-layer.

2. A decorated-part according to claim 1, characterized in that a width of the first laser-processed groove is greater than a width of the second laser-processed groove.

3. A decorated part according to claim 1, further wherein the second laser-processed groove is spaced from a side wall of the first laser-processed groove such that a portion of the surface coat-layer is positioned between the side wall and the second laser-processed groove.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a layout-sketch of the laser-decorating device as an embodiment of this invention.

(2) FIG. 2 is a partially enlarged plan-view of the automobile interior-part as an embodiment of this invention.

(3) FIG. 3 is the enlarged cross-sectional view of the main part of the automobile interior-part as an embodiment of this invention.

(4) FIG. 4 is the enlarged cross-sectional view of the main part that explains the manufacturing process of the automobile interior-part as an embodiment of this invention.

(5) FIG. 5 is the enlarged cross-sectional view of the main part that explains the manufacturing process of the automobile interior-part as an embodiment of this invention.

(6) FIG. 6 is the enlarged cross-sectional view of the main part that explains the manufacturing process of the automobile interior-part as an embodiment of this invention.

(7) FIG. 7 is the enlarged cross-sectional view of the main part that explains the manufacturing process of the automobile interior-part as an embodiment of this invention.

(8) FIG. 8 is the enlarged cross-sectional view of the main part that explains the manufacturing process of the automobile interior-part as an embodiment of this invention.

(9) FIG. 9 is the enlarged cross-sectional view of the main part that explains the manufacturing process of the automobile interior-part as an embodiment of this invention.

(10) FIG. 10 shows photographs (in the left column) of the enlarged plan-view and of the three-dimensional image of the first laser-processed groove of the conventional automobile interior-part and shows (in the right column) photographs of the enlarged plan-view and of the three-dimensional image of the first laser-processed groove of the automobile interior-part as an embodiment of this invention.

(11) FIG. 11 is an enlarged cross-sectional view of the main-part of the conventional automobile interior-part as a comparative example.

MODES FOR CARRYING OUT THE INVENTION

(12) Hereinafter, an embodiment of this invention showing an automobile interior-part and a method for manufacturing the same is precisely described in reference to FIGS. 1 to 10.

(13) As shown in FIGS. 2 and 3, the automobile interior-part 11 (i.e. the decorated part) of this invention comprises a three-dimensional resin-base material 12 and a plurality of coat-layers (the first base coat-layer 21B, the second base coat-layer 21C and surface coat-layer 31) formed in a laminated fashion so as to cover the surface 13 of the resin base-material 12. The resin base-material 12 as the embodiment of this invention is described as comprising a flat-shaped main part 14 and a pair of side parts 15 set so as to connect to the flat-shaped main part 14 (see FIG. 1). Since the angle between the main part 14 and the pair of side parts 15 is approximately 90 degrees, this resin base-material 12 is of substantially a U-shaped form. The automobile interior-part 11 as the embodiment of this invention is a part for configuring e.g. an armrest of an automobile door.

(14) For example, an ABS resin or the like is used as the resin-base material 12 of the embodiment of this invention. It is possible also to choose a resin material such as a PC resin or a mixture of the ABS resin and the PC resin. The color of the resin base-material 12 is not specified. Any color of such resin material can be used according to the product feature, type or the like. However, the color black is used here in this invention.

(15) The first base coat-layer 21B is formed on the surface 13 of the resin-base material 12. The first base coat-layer 21B is made of a coat-layer colored in a highly light color at a lightness-level of 70 or more (specifically, of a white-resin material at a lightless-level of 80 or more; of a milky-white resin-material at a lightness-level of 70 or more; of a grayish-white resin-material at a lightness-level of 70 or more; or made of an ivory-resin material colored at a lightness level of 70 or more). Of the above coloring designation of the first base coat-layer 21B, “a highly light color at a lightness level of 70 or more” and not only a non-chromatic color is used. Yet, a slightly chromatic color can be used.

(16) Here, the thickness of the first base coat-layer 21B is not particularly limited, but it is favorable to set the thickness at least at 5 μm or more, because if the thickness of the first base coat-layer 21B is too thin, the infrared laser L1 is insufficiently reflected by the base coat-layer 21B in the laser-decorating process. Yet, going through the side of the resin base-material 12 carries the high risk that the heat of the infrared laser L1 is likely to be absorbed therein. In this case, gasification of the resin base-material 12 cannot be effectively prevented, and then an air-foam-induced bulge is likely to be formed. Considering such circumstances, it is preferable to set the thickness of the first base coat-layer 21B at 10 to 30 μm (specifically at 15 to 20 μm for the embodiment of this invention). In fact, the thickness of the first base coat-layer 21B should be minimal, since the first base coat-layer 21B is simply for providing reflexibility of the infrared laser L1. Also, increasing the thickness of the base coat-layer 21 unnecessarily (such as at 30 μm or more) may result in higher costs in production.

(17) The second base coat-layer 21C, colored in a chromatic color except in black and white, is formed on the surface of the first base coat-layer 21B. Specifically, the second base coat-layer 21C, colored in red by adding a red pigment, is formed, and, as for the embodiment of this invention, is colored in red at a lightness-level of about 90 and at the chromatic-value of about 90.

(18) The surface coat-layer 31, colored in a low-light color at a lightness-level of 20 or less, is formed on the second base coat-layer 21C. Specifically, by adding carbon black as a black pigment (of a content of four percent per volume or more), the surface coat-layer 31, colored in black at a lightness-level of about 18 and at the chromatic-value of about 2, is formed. The surface coat-layer 31 is colored by using a black pigment for the embodiment of this invention, but a dark color other than black (e.g. a blackish green, a blackish brown or the like) can be used if the condition of the lightness-level being 20 or less is satisfied. Specifically, it is possible to color the surface coat-layer 31 by mixing a black pigment with a dark chromatic color pigment other than black, accordingly.

(19) The thickness of the surface coat-layer 31 is set greater than that of the second base coat-layer 21C. Specifically, the former should be 20 μm to 40 μm (approximately 30 μm for the embodiment of this invention), and the latter should be 10 μm to 20 μm (approximately 15 μm for the embodiment of this invention). Making the thickness of the surface coat-layer 31 less than that of the second base coat-layer 21C may inhibit the function of the surface coat-layer 31 as being a sufficient protective-layer on the uppermost surface of the surface coat-layer 31 and may also make it difficult to form the second laser-processed groove 32. In addition, the thickness of the second base coat-layer 21C should be minimal, since the base coat-layer 21C is simply for providing contrast in coloring. Also, increasing the thickness of the base coat-layer 21C unnecessarily may result in higher costs in production.

(20) As shown in FIGS. 2 and 3, a plurality of two different laser-processed grooves 22, 32 respectively are formed in the surface coat-layer 31 as the embodiment of this invention. Specifically, as shown in FIG. 2, two rectangular-shaped patterns are drawn on the surface of the surface coat-layer 31. One of two such patterns incorporates both of the two different laser-processed grooves 22, 32, with a plurality of second laser-processed grooves 32 therein drawn in parallel obliquely upward to the right. The other drawn pattern incorporates only the one type of laser-processed grooves 32 that are plurally drawn therein in parallel obliquely upward to the left. Also, these two drawn patterns are alternately provided.

(21) As shown in FIG. 3, the first laser-processed groove 22 fully penetrates the surface coat-layer 31 to expose partially the surface of the second base coat-layer 21C that is red in color. The first laser-processed groove 22 as the embodiment of this invention is formed L-shape in planar view. On the other hand, the second laser-processed groove 32 is shallower than the first laser-processed groove 22 and is formed so as not to penetrate the surface coat-layer 31. Specifically, the depth of the first laser-processed groove 22 is 20 μm to 40 μm (approximately 30 μm for the embodiment of this invention), and the depth of the second laser-processed groove 32 is 5 μm to 15 μm (approximately 10 μm for the embodiment of this invention). Also, the width w1 of the first laser-processed groove 22 is greater than the width w2 of the second laser-processed groove 32. Specifically, the width of the former should be set at 80 μm to 150 μm (approximately 100 μm, for the embodiment of this invention), and the width of the latter should be set at 50 μm to 100 μm (approximately 70 μm for the embodiment of this invention).

(22) The exposed surface-area 26 of the second base coat-layer 21C at the bottom of the first laser-processed groove 22 is relatively flat, and its arithmetic-average roughness (Ra) is 2 μm or less. The maximum height (Ry) of the exposed area 26 is 7 μm or less, and the 10-point average roughness (Rz) of said exposed area 26 is 8 μm or less. The non-exposed area 27 of the second base coat-layer 21C not at the bottom of the first laser-processed groove 22, is of average value in height h1 from the standard point, that is, from the surface 13 of the resin base-material 12 up to the surface of the exposed area 26, is 100 or more and 130 or less, under the condition that the average value in height h2 from the standard point, that is, from the surface 13 of the resin base-material 12 up to the surface of the non-exposed area 27 is 100.

(23) FIG. 1 shows the laser-decorating device 41 used in providing a design on the pre-decorated automobile interior-part 11. Such laser-decorating device 41 as the embodiment of this invention comprises a supporting table 42 for supporting the automobile interior-part 11; a work-displacement robot 43 for moving the supporting table 42 to change the posture and position or the like of said automobile interior-part 11; a laser-irradiating device 44 for irradiating the infrared laser L1 onto the decorated-surface of the automobile interior-part 11; and a control device 45 for activating and controlling the work-displacement robot 43 and the laser-irradiating device 44.

(24) The work-displacement robot 43 comprises a robot arm 46 with a supporting table 42 at the tip. Of the work-displacement robot 43, the robot arm 46 is activated to move the supporting table 42 from side to side, up and down and in a rotational direction to change the position and posture of the automobile interior-part 11, thus changing the irradiation position and irradiation angle of the infrared laser L1 against the decorated-surface of the automobile interior-part 11.

(25) The laser-irradiating device 44 comprises a laser generator 51 for generating the infrared laser L1 at a given wavelength (e.g. a YVO.sub.4 laser of a wavelength of 1,064 nm); a laser deflector 52 for deflecting the infrared laser L1; a laser controller 53 for controlling the laser generator 51 and the laser deflector 52. The laser deflector 52 is an optics system comprising a lens 54 and a reflective mirror 55. The irradiation position and the focal point of the infrared laser L1 can be adjusted by changing the position of the lens 54 and the reflective mirror 55. The laser controller 53 controls the laser generator 51 and the laser deflector 52, thus adjusting the laser-irradiation conditions such as the irradiation intensity and the scanning rate of the infrared laser L1.

(26) The controller 45 is configured of a well-known computer made of a CPU 61, of a memory 62, and of an input-output port 63 or the like. The controller 45 is connected electrically to the work-displacement robot 43 and the laser-irradiating device 44 that are driven and controlled by various drive-signals.

(27) The memory 62 of the controller 45 incorporates programs and data for drawing the design onto the decorative surface of the automobile interior-part 11. Specifically, such data is configuration-data for indicating the three-dimensional formation of the automobile interior-part 11 and other data such as pattern-data or the like according to the pattern to be drawn onto said automobile interior-part 11. Also, the memory 62 incorporates the programs and the data for controlling the work-displacement robot 43 and the laser-irradiating device 44.

(28) The method for manufacturing the automobile interior-part 11 is described in reference to FIGS. 4 to 7.

(29) Firstly, prepare the resin base-material formed by using the ABS resin (see FIG. 4) Then, make the first base coat-layer 21B, colored in white at a lightness-level of 80 or more, or colored in a milky-white at a lightness-level of 70 or more, or colored in a grayish-white or in ivory, on the surface 13 of the resin base-material 12 by the conventionally known method (see FIG. 5 of the first base coat-layer-forming process). Furthermore, make the second base coat-layer 21C, colored in red by adding the red pigment, on the first base coat-layer 21B by the conventionally known method (see the FIG. 6 of the second base coat-layer-forming process). After that, make the surface coat-layer 31 in a less-light color at a lightness-level of 20 or less on the second base coat-layer 21C (see FIG. 7 of the surface coat-layer-forming process), so that the whole area of the surface 13 of the three-dimensional resin base-material 12 (of the main part 14 and of the side parts 15) becomes a decorative surface.

(30) In the next laser-decorating process, first set the resin base-material 12 on the supporting table 42 of the work-displacement robot 43 (see FIG. 1). Next, the CPU 61 retrieves from the memory 62 the laser-irradiation data for irradiating the laser. The CPU 61 then produces a drive-signal according to the laser-irradiation data and then emits such drive-signal to the laser-irradiating device 44, which then irradiates the infrared-laser L1 according to the drive-signal being emitted by the CPU 61. Also, the laser controller 53 of the laser-irradiating device 44 makes the laser generator 51 irradiate the laser L1 and controls the laser deflector 52 according to the pattern of the given image data. Such control determines the irradiating position and the focal point of the infrared laser L1. All of the above controls make it possible to conduct a certain laser irradiation to form a group of laser-processed grooves of the multiple laser-processed grooves 22, 32, thus providing a certain pattern, as shown in FIG. 2, and therefore providing a fine decoration on the surface of the automobile interior-part 11.

(31) In the laser-decorating process, the laser-irradiation is conducted specifically in the following order.

(32) Firstly, make the first laser-processed groove 22, which penetrates the surface coat-layer 31, to expose partially the second base coat-layer 21C, by irradiating the infrared laser L1 onto the surface coat-layer 31 (see FIG. 8). Then, without penetrating the surface coat-layer 31, make the second laser-processed groove 32, which is shallower than the first laser-processed groove 22, on the surface coat-layer 31 by irradiating the infrared laser L1 onto the surface of said surface coat-layer 31 (see FIG. 9). The above ordered process prevents smoke and soot from gathering in the second laser-processed groove 32, while forming the first laser-processed groove 22, which brings the advantage of eliminating the possibility of gloss-deterioration.

(33) The automobile interior-part 11 as the embodiment of this invention, and a comparative example of the conventional automobile interior-part, were actually made and observed. The result is as follows:

(34) FIG. 10 shows photographs (in the left column) of the enlarged plan-view and of the three-dimensional image of the first laser-processed groove 22 of a conventional automobile interior-part and shows (in the right column) photographs of the enlarged plan-view and of the three-dimensional image of the first laser-processed groove 22 of the automobile interior-part 11 as an embodiment of this invention. FIG. 11 is an enlarged cross-sectional view of the main part of the conventional automobile interior-part as a comparative example. The only difference of this comparative example from the embodiment of this invention is that this comparative example does not have the first base coat-layer 21B.

(35) As shown in FIG. 11, it was identified in the comparative example of the conventional automobile interior-part that the exposed area 26 of the second base coat-layer 21C at the bottom of the first laser-processed groove 22 bulges, that the surface-flatness of the exposed area 26 is less realized, and that an air-foam B1 is formed on the surface of the resin base-material 12 beneath the base coat-layer 21 of the exposed area 26 of the base coat-layer 21, which may suggest a deterioration of the adhesion between the resin base-material 12 and the second base coat-layer 21C. The laser-microscope determination of the surface-roughness of the exposed area 26 of the second base coat-layer 21C showed that the arithmetic-average roughness (Ra) was 2.773 μm, that the maximum height (Ry) was 10.749 μm, and that the ten-point average roughness (Rz) was 11.569 μm respectively. Also, the planar-view microscope-determination of the exposed area 26 identified that the formed air-foam B1 deteriorates the surface of the exposed area 26 (see the left column of FIG. 10). The planar view unaided observation of the comparative example of the conventional automobile-interior-part showed that the red color of the exposed area 26 was unclear and of a less high contrast.

(36) Contrarily, as shown in FIGS. 2 and 3, it was identified in the automobile interior-part 11 as the embodiment of this invention that the surface of the exposed area 26 of the second base coat-layer 21C at the bottom of the first laser-processed groove 22 is not bulged, that the flatness of the exposed area 26 is realized, that such realized flatness is kept at a high level, and that there is not an air-foam B1 formed at all on the surface of the resin base-material 12 beneath the base coat-layer at the bottom of the exposed area 26, which means that the adhesion between such resin base-material 12 and base coat-layer is kept in a preferable state. The laser-microscope determination of the surface-roughness of the exposed area 26 of the second base coat-layer 21C showed that the arithmetic-average roughness (Ra) was 0.814 μm, that the maximum height (Ry) was 2.768 μm, and that the ten-point average roughness (Rz) was 3.207 μm, which were obviously less than the values of the comparative example. The planar-view unaided determination of the comparative example of the automobile interior-part 11 of this invention showed that the surface condition of the exposed area 26 was extremely good (see the right column of FIG. 10). The planar view unaided observation of the automobile interior-part 11 of this invention showed that the red color of the exposed area 26 was clear and of a high contrast.

(37) Therefore, the following effects can be achieved by the embodiments of this invention.

(38) (1) In the manufacturing process of the automobile interior-part 11 as an embodiment of this invention, the first base coat-layer 21B, colored in a highly light color at a lightness-level of 70 or more, is formed on the resin base-material 12. Then, the laser-decorating process is proceeded. As such, in the laser-decorating process, the infrared laser L1 is reflected by the first base coat-layer 21B, thus avoiding heat absorption. Moreover, the resin will not be gasified and thus an air foam-induced bulge is not readily formed. Therefore, the flatness of the exposed area 26 of the second base coat-layer 21C at the bottom of the first laser-processed groove 22 is realized. As a result, the exposed area 26 shows a clear color and a high contrast, thus making it possible to obtain an automobile interior-part 11 with an excellent design. Also, the adhesion of the base coat-layer 21 against the resin base-material 12 does not lessen, thus making it possible to obtain a reliable decorated-part 11.

(39) (2) In the laser-decorating process of the method for manufacturing the embodiment of this invention, in addition to the first laser-processed groove 22, the second laser-processed groove 32 is made, so that a complex and fine design can be expressed, thus making it possible to improve the excellency of the design.

(40) (3) In the laser-decorating process of the method for manufacturing an embodiment of this invention, the second laser-processed groove 32 is made after the first laser-processed groove 22 is made. If the first laser-processed groove 22 of a relatively deep groove is made later than the second laser-processed groove 32 of a relatively shallow groove, then more gas is produced in the making of the first laser-processed groove 22, which causes soot and smoke to gather in the second laser-processed groove 32, which could result in less gloss of the second laser-processed groove 32. Contrarily, the embodiment of this invention that the first laser-processed groove 22 is started to be made in advance of the second laser-processed groove 32 prevents smoke and soot from gathering in the second laser-processed groove 32, which eliminates the risk of gloss-deterioration, thus making it possible to obtain a high-quality-designed automobile interior-part 11 of a clear second-laser-processed groove 32.

(41) (4) The automobile interior-part 11 as an embodiment of this invention comprises the second base coat-layer 21C colored in red as a chromatic color and the surface coat-layer 31 colored in black and to be formed on the base coat-layer 21. Of this automobile interior-part 11, the first laser-processed groove 22 penetrates the surface coat-layer 31 to expose partially the second base coat-layer 21C, while the second laser-processed groove 32 that is shallower than the first laser-processed groove 22 does not penetrate the surface coat-layer 31. Also, of the exposed area 26 of the second base coat-layer 21C, the arithmetic-average roughness (R1) is 2 μm or less, the maximum height (Ry) is 7 μm or less, and the 10-points average roughness (Rz) is 8 μm or less, which makes the flatness of the exposed area 26 realized, thus making it possible to achieve an exposed area 26 with distinctive coloring and high contrast.

(42) (5) Of the automobile interior-part 11 as an embodiment of this invention, the average value in the height h1 from the surface 13 of the resin base-material 12, as the standard point, up to the surface of the exposed area 26, is within the preferable range of 100 or more and 130 or less (specifically approximately 100). Contrarily, of the comparative example of the conventional automobile interior-part, the height h1 greatly exceeds the above preferable range (specifically over 150). In other words, the height of the bulge of the exposed area 26 of the automobile interior-part 11 of this invention, compared to the comparative example, is obviously very low, with the flatness of the exposed area realized, which makes the coloring of such an area distinctive and the contrast greater.

(43) (6) Of the automobile interior-part 11 as an embodiment of this invention, the thickness D1 (see FIG. 3) of the surface coat-layer 31 is greater than the thickness D2 of the second base coat-layer 21C. Making the thickness D1 of the surface coat-layer 31 less than the thickness D2 of the base coat-layer 21 may make it impossible to provide the function of the surface coat-layer 31 as being a sufficient protective layer on the uppermost surface of the surface coat-layer 31. In addition, the thickness of the base coat-layer 21 should be minimal, since the second base coat-layer 21C is simply for providing contrast. Increasing the thickness of the base coat-layer 21 unnecessarily may result in higher costs in production. On the contrary, the embodiment of this invention that the thickness D1 of the surface coat-layer 31 is greater than the thickness D2 of the second base coat-layer 21C can provide the function of the surface coat-layer 31 as being a protective layer on the uppermost surface of the surface coat-layer 31 and can prevent an increase of unnecessary thickness of the second base coat-layer 21C, thus making it possible to avoid higher costs in production. As such, the first laser-processed groove 22 and the second laser-processed groove 32 are readily made respectively, thus making it possible to avoid higher costs in production.

(44) Each embodiment of this invention can be modified, as described below.

(45) As described in the above embodiment of this invention, the second base coat-layer 21C is colored in red. However, it is possible to color it in another chromatic color (e.g. in blue, green, brown, orange, purple, yellow or the like).

(46) As described in the above embodiment of this invention, the second base coat-layer 21C is only a single coat-layer colored in red. However, double coat-layers in different colors can be adapted. For example, regarding such second base coat-layers 21C, 21C, it is possible to color the bottom layer in red and to color the upper layer in blue. The second base coat-layer 21C in red has the feature of not easily absorbing the infrared-laser L1, compared to the second base coat-layer 21C in blue, so that the infrared laser L1 penetrates the surface coat-layer 31, the first laser-processed groove 22 that partially exposes the second base coat-layer 21C in blue, as well as the surface coat-layer 31 and the second base coat-layer 21C in blue, thus making it possible partially to expose the second base coat-layer 21 in red. Therefore, it is possible to obtain the automobile interior-part 11 comprising the two color-exposed areas 26 of distinctive coloring and of great contrast. Also, instead of the second base coat-layer 21C being blue, it is possible to provide a coat-layer of another color that absorbs the energy of the infrared laser L1 more readily than red, and one that contains a chromatic color-pigment other than blue. Furthermore, it is possible to provide a coat-layer that contains a mixture of silver pigment and black pigment in a certain proportion.

(47) As described in the above embodiment of this invention, the YVO.sub.4 laser is used. However, it is not limited to that. The laser processing can be done using another solid-state laser that can irradiate the infrared laser L1 (e.g. a YAG laser, a ruby laser or the like).

(48) As described in the embodiment of this invention, the method for manufacturing decorative parts is embodied in the method for manufacturing component parts such as an armrest of a door as one of the automobile interior parts. However, it is possible to be embodied in this method for manufacturing decorative parts other component parts of automobile interior parts such as console boxes, instrument panels, sensor clusters, cup holders, glove compartments, upper boxes or safety-assist handles or the like. Besides automobile interior parts, this invention can be naturally embodied as a method for manufacturing decorative parts such as automobile exterior parts (e.g. radiator grills, emblems, mud guards or the like) or for manufacturing the decorative veneers of furniture, electric appliances or the like.

(49) Besides the technical ideas of this invention, as described above, other technical ideas to be understood are described hereinafter.

(50) (1) According to any one of the first through eleventh aspects as described above, the surface roughness (Ry) of the exposed area at the bottom of the first laser-processed groove of the second base coat-layer is 7 μm or less.

(51) (2) According to any one of the first through eleventh aspects as described above, the surface roughness (Rz) of the exposed area at the bottom of the first laser-processed groove of the second base coat-layer is 8 μm or less.

(52) (3) According to any one of the first through eleventh aspects as described above, there is no bulge between the surface of the resin base-material and the first base coat-layer or between the first base coat-layer and the second base coat-layer.

(53) (4) According to any one of the first through eleventh aspects as described above, of the second base coat-layer, the adhesion-intensity of the area at the bottom of the first laser-processed groove is the same as that of the area not at the bottom of the first laser-processed groove.

(54) (5) According to any one of the first through eleventh aspects as described above, the second base coat-layer is red.

(55) (6) According to any one of the first through eleventh aspects as described above, the second base coat-layer is made of two layers. The lower layer is colored in red, and the upper layer is colored in blue.

(56) (7) According to any one of the first through eleventh aspects as described above, the thickness of the surface coat-layer is 20 μm to 40 μm, the thickness of the first base coat-layer is 15 μm to 20 μm, and the thickness of the second base coat-layer is 10 μm to 20 μm.

DESCRIPTION OF REFERENCE NUMERALS

(57) 11: Automobile interior-part as the decorated-part

(58) 12: Resin base-material

(59) 13: Surface of the resin base-material

(60) 21B: First base coat-layer

(61) 21C: Second base coat-layer

(62) 22: First laser-processed groove

(63) 26: Exposed area

(64) 27: Non-exposed area

(65) 31: Surface coat-layer

(66) 32: Second laser-processed groove

(67) D1: Thickness of the second base coat-layer

(68) D2: Thickness of the surface coat-layer

(69) h1: Height from the surface of the resin base-material as the standard point up to the surface of the non-exposed area

(70) h2: Height from the surface of the resin base-material as the standard point up to the surface of the exposed area

(71) L1: Infrared laser

(72) w1: Width of the first laser-processed groove

(73) w2: Width of the second laser-processed groove