Patent Publication Number: US-2007108651-A1

Title: Decorative member

Description:
TECHNICAL FIELD  
      The present invention relates to a decorative member for use in, for example, a door panel or a cage wall panel of an elevator.  
     BACKGROUND ART  
      In a conventional sandblasting technique, a masking material (photomask) is attached to a base member to be worked such as glass or ceramic with a view to obtaining a worked face of a predetermined shape. (e.g., see-Patent Document 1).  
      However, such a technique requires films and developing agents each time. Also, cleaning with water involves generation of waste fluid. Thus, there have been demands for a countermeasure against adverse impacts on the environment.  
      Although there has been also proposed a method of performing sandblasting without using any masking material (e.g., see Patent Document 2), this method requires too much time to treat a large area. Further, the diameter of abrasive particles ranges approximately from 100 μm to several millimeters, so sufficient accuracy cannot be guaranteed in forming a pattern by means of sandblasting.  
      Patent Document 1: JP 10-138142 A  
      Patent Document 2: JP 10-560 A  
     DISCLOSURE OF THE INVENTION  
     Problems to be Solved by the Invention  
      As described above, the conventional working methods necessitates a countermeasure against adverse impacts on the environment. This countermeasure takes a lot of time and effort.  
      The present invention is made to solve the problems described above. It is thus an object of the invention to obtain a decorative member with an artistically accomplished design while sufficiently suppressing adverse impacts on the environment.  
      Means for Solving the Problems  
      To this end, according to one aspect of the present invention, there is provided a decorative member comprising: a base member having a design face; and a paint layer formed on the design face and containing a frosting paint for creating a frosted state during curing thereof, wherein the frosting paint is applied as a large number of dots; and the frosting paint is changed in application density to form a pattern on the paint layer. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a front view showing a decorative member according to Embodiment 1 of the present invention.  
       FIG. 2  is an enlarged illustrative view showing a first example of a state of application of the frosting paint to the uniform region of  FIG. 1 .  
       FIG. 3  is an enlarged illustrative view showing a second example of a state of application of the frosting paint to the uniform region of  FIG. 1 .  
       FIG. 4  is an illustrative chart showing a result of a comparative experiment in which degrees of finish resulting from different application methods of the frosting paint are compared with one another.  
       FIG. 5  is an illustrative view showing another example of a method of applying the frosting paint according to Embodiment 1.  
       FIG. 6  is an illustrative view showing still another example of the method of applying the frosting paint according to Embodiment 1.  
       FIG. 7  is an illustrative view showing yet another example of the method of applying the frosting paint according to Embodiment 1.  
       FIG. 8  is a schematic diagram showing a first example of a printing system for applying the frosting paint of  FIG. 1 .  
       FIG. 9  is a schematic diagram showing a second example of a printing system for applying the frosting paint of  FIG. 1 .  
       FIG. 10  is a perspective view showing how a base member  1  is inserted into the printer of  FIG. 9 .  
       FIG. 11  is a side view showing essential parts of the printer body of  FIG. 9 .  
       FIG. 12  is a side view showing how air is sprayed onto the base member of  FIG. 11 .  
       FIG. 13  is a side view showing how a paint is applied to the base member of  FIG. 12  and ultraviolet rays are radiated.  
       FIG. 14  is a sectional view showing a decorative member according to Embodiment 2 of the present invention.  
       FIG. 15  is a sectional view showing another method of applying the frosting paint of  FIG. 14 .  
       FIG. 16  is a sectional view showing a decorative member according to Embodiment 3 of the present invention. 
    
    
     BEST MODES FOR CARRYING OUT THE INVENTION  
      Preferred embodiments of the present invention will be described hereinafter with reference to the drawings.  
     Embodiment 1  
       FIG. 1  is a front view showing a decorative member according to Embodiment 1 of the present invention. Referring to this figure, a base member  1  is made of a metal panel. Usable as this metal are, for example, a stainless steel, aluminum, an aluminum alloy, a magnesium alloy, titanium, or a titanium alloy.  
      The base member  1  has a design face  1   a . Only one of a plurality of faces constituting the base member  1  may be used as a design face  1   a  or some of those faces may be used as design faces  1   a . Each design face  1   a  is polished to enhance glossiness thereof.  
      A paint layer  2  is formed on the design face  1   a  by applying a paint thereto. The paint layer  2  includes a transparent frosting paint region that is frosted as a frosting paint cures, and a normal transparent paint region to which a normal transparent paint different from the frosting paint is applied.  
      The surface of the frosting paint is not smoothened even after its curing, and forms a three-dimensional painted surface having slight elevations corresponding to respective particles. The frosting paint is cured by, for example, being irradiated with ultraviolet rays. Specific examples of the frosting paint are disclosed in, for example, JP 6-312495 A and Japanese Patent No. 3004897.  
      The frosting paint and the transparent paint are applied as a large number of dots. A pattern (picture or figure) is formed on the paint layer  2  by changing the application density of the frosting paint. The pattern (picture or figure) is formed on the paint layer  2  also through combination of the frosting paint region and the transparent paint region.  
      More specifically, the transparent paint is applied to a translucent region  3  indicated by oblique lines in  FIG. 1 . In the translucent region  3 , the design face  1   a  of the base member  1  as a background is visible through the paint layer  2 . The frosting paint is applied to a uniform region  4  of  FIG. 1  with a constant dot density (application density). The pattern in a change region  5  of  FIG. 1  is gradated by continuously changing the dot density of the frosting paint. The frosting paint is applied to a low-density region  6  of  FIG. 1  uniformly but less densely (coarsely) than to the uniform region  4 .  
       FIG. 2  is an enlarged illustrative view showing a first example of a state of application of the frosting paint in the uniform region  4  of  FIG. 1 .  FIG. 3  is an enlarged illustrative view showing a second example of a state of application of the frosting paint in the uniform region  4  of  FIG. 1 . Referring to  FIG. 2 , a plurality of centerlines passing through the centers of respective dots intersect with one another at right angles. Referring to  FIG. 3 , a plurality of centerlines passing through the centers of respective dots intersect with one another at predetermined angles other than right angles. Referring to  FIGS. 2 and 3 , d and L denote the diameter of the dots and the distance between centers of the dots, respectively.  
       FIG. 4  is an illustrative chart showing a result of a comparative experiment in which degrees of finish resulting from different application methods of the frosting paint are compared with one another. In this experiment, a subjective evaluation was made as to the change in glossiness and the reproducibility of glossiness. It should be noted in the result of this evaluation that each double circle means “very good”, that each circle means “good”, that each triangle means “somewhat problematic”, and that each X mark means “unserviceable”.  
      In the experiment, the degrees of finish were evaluated by changing the condition of a combination of a dot diameter and a dot pitch. The dot pitch represents a ratio of the distance between the centers of the dots to the dot diameter. For instance, a dot pitch of 200% means that the distance L between the dots in  FIGS. 2 and 3  is twice as long as the dot diameter d.  
      As shown in  FIG. 4 , an increase in dot diameter leads to stable reproducibility but makes it impossible to confirm a change in glossiness. In contrast, a visually recognizable change in glossiness becomes obvious in accordance with a decrease in dot diameter. It has also been confirmed that an increase in dot diameter brings about fusion of adjacent dots prior to the curing of the frosting paint and thus makes it impossible to ensure a dot pitch.  
      It is therefore preferable to set the dot diameter of the frosting paint equal to or smaller than 65 μm. Further, it is preferable to apply the frosting paint so that the distance between the centers of adjacent dots becomes larger than the dot diameter and equal to or smaller than 300% thereof.  
      Reference is then made to  FIG. 5 , which is an illustrative view showing another example of a method of applying the frosting paint according to Embodiment 1. In the example of  FIG. 5 , the frosting paint is applied linearly. Thus, a linear pattern of the frosting paint is drawn on the design face  1   a . A gradational expression is made possible by gradually changing the distance between the centers of adjacent dots.  
       FIG. 6  is an illustrative view showing still another example of the method of applying the frosting paint according to Embodiment 1. In the example of  FIG. 6 , the frosting paint is applied in the form of a plurality of straight lines arranged apart from and parallel to one another. A finish similar to that of hairline machining can be obtained by thus drawing a plurality of straight lines using the frosting paint.  
      Further,  FIG. 7  is an illustrative view showing yet another example of the method of applying the frosting paint according to Embodiment 1. In the example of  FIG. 7 , the frosting paint is applied in the form of a plurality of curves. The frosting paint is also applied in the form of a plurality of circles overlapping with one another. A finish similar to that of scratching can be obtained by thus drawing a plurality of curves using the frosting paint.  
      In the decorative member described above, the frosting paint is applied as a large number of dots, and a pattern is formed on the paint layer  2  by changing the application density of the frosting paint. Therefore, waste fluid containing chrome and nickel, a large amount of dust due to sandblasting, waste water and waste materials, various solvents as a result of the manufacture of a masking material can be prevented from being generated, and a decorative member with an artistically accomplished design can be obtained while sufficiently reducing adverse impacts on the environment.  
      The pattern is formed on the paint layer  2  also through combination of the frosting paint region  4 ,  5 , or  6  and the transparent paint region  3 . Thus, a decorative member with a more varied design of high artistic quality can be obtained.  
      Moreover, the design face  1   a  as the background of the paint layer  2  is polished to enhance glossiness thereof, so a finish providing a feeling of good quality is achieved through effective use of metallic luster of the design face  1   a.    
      Reference is then made to  FIG. 8 , which is a schematic diagram showing a first example of a printing system for applying the frosting paint of  FIG. 1 . A paint injection unit  11  has a nozzle portion  12  for applying the frosting paint to the base member  1  through injection and an angle adjustment portion  13  for adjusting the angle of the nozzle portion  12  with respect to the base member  1 . The paint injection unit  11  is further provided with a discharge amount control portion (not shown) for controlling the discharge amount of the frosting paint. The paint injection unit  11  is supported by a drive unit  14 .  
      The drive unit  14  has a first position control rail  15  for guiding a movement of the paint injection unit  11  in a primary scanning direction (laterally in  FIG. 8 ) and a pair of second position control rails  16   a  and  16   b  for guiding movements of the paint injection unit  11  and the first position control rail  15  in a secondary scanning direction. The drive unit  14  is further provided with a pulse motor (not shown), a wire (not shown), and the like for driving.  
      A paint tank  18  and an air tank  19  are connected to the paint injection unit  11  via a flexible feed tube  17 . The frosting paint is accommodated in the paint tank  18 . A feed control portion  20  controls the feed amount of the frosting paint and the pressure in the air tank  19 .  
      A printer control portion  21  controls the discharge amount control portion of the paint injection unit  11  and the drive unit  12 . A computer  22  such as a personal computer controls the printer control portion  21 . The printer control portion  21  is connected to the computer  22  via a control cable  23 . The computer  22  is connected to a network  24  to which a plurality of other computers  22  are connected.  
      Next, a method of manufacturing a decorative member using the printing system of  FIG. 8  will be described. First, the base member  1  is set at a predetermined position so that the design face  1   a  faces the nozzle portion  12 . A pattern to be recorded on the design face  1   a  is created using graphic-type software on the computer  22 .  
      After that, the created pattern is converted into a predetermined control signal on the computer  22 . This control signal is outputted to the printer control portion  21 . When the control signal is inputted to the printer control portion  21 , the position of the nozzle portion  12  is controlled by controlling the drive unit  12 . Also, the discharge amount control portion for controlling the discharge amount of the frosting paint is controlled to ensure a suitable dot diameter.  
      The transparent paint is applied using a common printer designed to selectively change the paint type. However, the transparent paint can also be applied using another printer after the frosting paint has been applied.  
      Reference is then made to  FIG. 9 , which is a schematic diagram showing a second example of a printing system for applying the frosting paint of  FIG. 1 . Referring to the figure, a plurality of computers  22  and a server  25  are connected to the network  24 . A printer  26  is connected to each of the computers  22  via the control cable  23 .  
      An inkjet printer is used as the printer  26 . Each printer  26  has a printer body  27  and an openable and closable cover  28 . A lateral face of the printer body  27  is provided with an exhaust port  27   a.    
      A clean unit  29  for taking in and purifying air (removing dust therefrom) is connected to the printer  26  via a duct  30 . The air taken in and purified by the clean unit  29  is introduced into the printer  26  via the duct  30 . Provided between the clean unit  29  and each printer  26  is a pressure adjustment unit  31  for adjusting the pressure of air introduced into the printer  26 .  
       FIG. 10  is a perspective view showing how the base member  1  is inserted into the printer  26  of  FIG. 9 . As shown in  FIG. 10 , the base member  1  can be set at a predetermined position within the printer  26  by opening the cover  28 .  
       FIG. 11  is a side view showing essential parts of the printer body  27  of  FIG. 9 . The printer body  27  is provided with a conveyance table  32  for supporting the base member  1  horizontally and causing it to reciprocate in the secondary scanning direction (laterally in the figure). A pair of head guide rails  33  are arranged horizontally above the conveyance table  32 .  
      A printer head  34  is supported by the head guide rails  33 . The printer head  34  is driven in the primary scanning direction along the head guide rails  33  by means of drive means (not shown). In other words, the head guide rails  33  are arranged parallel to the primary scanning direction to guide a movement of the printer head  34  in the primary scanning direction.  
      An on-demand piezoelectric head is used as the printer head  34 . The printer head  34  has a paint nozzle portion  35  for injecting the frosting paint toward the design face  1   a  of the base member  1  and a plurality of air nozzle portions  36  for spraying air introduced through the duct  30  ( FIG. 9 ) onto the design face  1   a . Air in the form of a laminar air curtain is injected from the air nozzle portions  36 . The air nozzle portions  36  are so arranged as to surround the paint nozzle portion  35 .  
      An ultraviolet ray radiation unit  37  for radiating ultraviolet rays onto the frosting paint applied to the design face  1   a  to cure the frosting paint is provided in the vicinity of the printer head  34 . The ultraviolet ray radiation unit  37  is mounted to a structural component of the printer  26 , for example, the cover  28 , except the conveyance table  32 , the head guide rails  33 , and the printer head  34 .  
      Next, a method of manufacturing a decorative member using the printing system of  FIG. 9  will be described. First, the cover  28  is opened and the base member  1  is laid on the conveyance table  32  with the design face  1   a  facing upward. The cover  28  is then closed to seal the printer  26  hermetically. After that, purified air is introduced into the printer  26  through the duct  30 .  
       FIG. 12  is a side view showing how air is sprayed onto the base member  1  of  FIG. 11 . Although not shown in  FIG. 11 , air nozzle portions  38  are provided in the printer  26  below the conveyance table  32  as well. Thus, purified air is injected from the air nozzle portions  36  and  38  arranged at the respective locations in the hermetically sealed printer  26 . At this moment, the angle at which air is sprayed can be adjusted.  
      The injected air is discharged from the exhaust port  27   a  ( FIG. 9 ). Further, a degree of cleanness of the discharged air is monitored. When a preset degree of cleanness is maintained for a predetermined period, the introduction of air into the printer  26  is stopped or the pressure of air is automatically adjusted (reduced) by the pressure adjustment unit  31  to apply a pre-charge pressure to the interior of the printer  26  through the gradual introduction of air.  
      A pattern to be recorded on the design face  1   a  is created using graphic-type software on the computer  22 . Data saved in the server  25  can be used to create the pattern.  
      After that, the created pattern is converted into a predetermined control signal on the computer  22 . This control signal is outputted to the printer  26 . When the control signal is inputted to the printer  26 , the position of the printer head  34  is controlled, and the discharge amount control portion for controlling the discharge amount of the frosting paint is controlled to ensure a suitable dot diameter. Then, the pattern is printed on the design face  1   a . As shown in  FIG. 13 , ultraviolet rays are radiated by the ultraviolet ray radiation unit  37  onto the frosting paint applied to the design face  1   a , to thereby cure the frosting paint.  
      The transparent paint is applied using a common printer designed to selectively change the paint type. However, the transparent paint can also be applied using another printer after the frosting paint has been applied.  
      When the pattern is printed on the design face  1   a  as described above, a distance position between the centers of the dots most suited for the dot diameter is defined by the computer  22 , and the pattern is processed based on information regarding this definition, utilizing error diffusion, a Dither method, or FM screening.  
     Embodiment 2  
      Reference is then made to  FIG. 14 , which is a sectional view of a decorative member according to Embodiment 2 of the present invention. In this example, a large number of bubbles  2   a  are formed in the frosting paint layer  2  made of the frosting paint. In other words, as the frosting paint used in Embodiment 2 cures, the bubbles  2   a  are generated therein to create a frosted state.  
      By thus using the frosting paint generating bubbles during its curing, it becomes possible to keep the surface shape of the dots smooth and prevent microscopic dirt from adhering thereto. That is, while such a frosting paint as creates a frosted state through generation of microscopic uneven regions (or crimps) on the surface during its curing may allow dirt to adhere to the uneven regions, the frosting paint of Embodiment 2 makes the adhesion of dirt relatively unlikely.  
      Although the dots of the frosting paint are spaced apart from one another in  FIG. 14 , the frosting paint may also be applied so that no space is generated among the dots as shown in, for example,  FIG. 15 .  
     Embodiment 3  
      Reference is then made to  FIG. 16 , which is a sectional view of a decorative member according to Embodiment 3 of the present invention. In this example, the paint layer  2  is three-dimensionally formed by laminating a plurality of unit paint layers  41 . The unit paint layers  41  are applied and cured one by one. In other words, after a first one of the unit paint layers  41  has been cured, a second one of the unit paint layers  41  is applied thereto.  
      In this manner, the three-dimensional paint layer  2  can also be formed to achieve a distinctive variation in design.  
      An inorganic material or an organic material can be used as the base member. Usable as the inorganic material other than metal are, for example, glass, stone, china, and ceramic. Usable as the organic material are, for example, resin and wood.  
      During application of the paint, the design face may be vertically erected, horizontally laid, or tilted.  
      Furthermore, although the paint layer is formed directly on the base member in the above-mentioned examples, a background colored layer or an antirust layer may be applied or an ink-stained colored pattern layer may be formed between the base member and the paint layer.