Abstract:
A coating compound and method for a portable electronic apparatus having frequent contact with users, such as a portable terminal, a Portable Multimedia Player (PMP), a Personal Digital Assistant (PDA), or the like. A housing of the portable electronic apparatus has the coating compound coated arranged thereon, and a bead portion is blended and added to the coating compound prior to applying the coating compound onto the housing so that convexes and concaves are formed on and in an outer surface of the housing by the bead portion. The coating method includes manufacturing a housing of the portable electronic apparatus by injection, coating the coating compound onto the manufactured housing, and drying the coating compound coated onto the housing so that particles of acrylic beads and urethane beads included in the coating compound protrude from an outer surface of the housing.

Description:
CLAIM OF PRIORITY 
       [0001]    This application claims the benefit under 35 U.S.C. §119(a) from a Korean Patent Application filed in the Korean Intellectual Property Office on Nov. 24, 2008 and assigned Serial No. 2008-0117100, the entire disclosure of which is hereby incorporated by reference in its entirety. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a coating compound for a portable electronic apparatus and a coating method for the portable electronic apparatus. More particularly, the present invention relates to a coating compound for a housing of an portable electronic apparatus having frequent contact with users, such as a portable terminal, a Portable Multimedia Player (PMP), a Personal Digital Assistant (PDA), or the like, and a coating method for same. 
         [0004]    2. Description of the Related Art 
         [0005]    Generally, portable electronic apparatuses, such as portable terminals, MP3 players, Portable Multimedia Players (PMPs), Personal Digital Assistants (PDAs), and so forth, allow users to enjoy various contents while moving around on foot, bicycle, in motor vehicles, airplanes, boats, etc. Such portable electronic apparatuses are becoming increasingly multifunctional and yet miniaturized to comply with consumers&#39; demands. 
         [0006]    In particular, portable terminals refers to electronic apparatuses which enable users to perform wireless communication with other such devices or a network while carrying them around. Typically, portable terminals are classified into several categories, including bar-type portable terminals, flip-type portable terminals, folder-type portable terminals, and sliding-type portable terminals based, the categories being based on how these devices are opened or closed. To enhance portability, such portable terminals are often miniaturized when compared to older versions, so as to facilitate increased portability. 
         [0007]    However, as multimedia functions, such as digital multimedia broadcasting (DMB), moving picture file appreciation, and the like, are expanding in functionality and content, the size of the portable terminal is increasing to some extent so that a sufficient size of a display device can be secured to view the content. As a result, the effort in size-reduction of the portable terminal has been focused on reducing an overall thickness of the portable terminal by reducing a thickness of an outer housing of the portable terminal, thereby making the portable terminal slimmer. 
         [0008]    To secure shock and abrasion resistances for the slim portable terminal in spite of the small thickness, a housing is made in part of a metal material and another part of the housing is made of a synthetic resin material. The synthetic resin used to make the housing comprises poly carbonate, which is generally deformed at a temperature of about 100° C., and thus the exterior of the housing is coated with a coating material such as urethane resin and then dried at a low temperature of less than 80° C. However, in order to prevent deformation of a synthetic resin part of the housing of the conventional portable terminal, for at least 90 minutes and at most 180 minutes are taken at a low temperature of less than 80° C. after coating, lowering productivity. Moreover, the synthetic resin part of the housing of the conventional portable terminal is easily damaged because of its vulnerability to shock. 
         [0009]    With regard to the housing, a coating material used in the housing comprises a waterborne polyurethane resin, a water-soluble chlorinated polyolefin emulsion, a water-soluble polyethylene resin, a waterborne acrylic urethane resin, and so forth. Generally, however, a solvent-based oily resin is normally used in consideration of workability. To represent the texture of the appearance through coating of the housing, glass beads or acrylic beads are used. When either only glass beads or only acrylic beads are used, they generally have an average diameter of 5-8 μm, resulting in degradation of the effect in expressing the texture. Furthermore, two or more coating materials have to be used for texture expression. 
         [0010]    Accordingly, there is a long-felt need in the art for a coating compound for a portable electronic apparatus, which makes it possible to express texture with a single coating layer, instead of conventional two or more coating layers, and a coating method for the portable electronic apparatus. There is also a long-felt need in the art for a coating compound for a portable electronic apparatus, which allows expression of vivid metallic texture through diffused reflection brightness by using acrylic beads or urethane beads and also allows expression of a color impression like aluminum sanding, and a coating method for the portable electronic apparatus. 
         [0011]    There is also a long-felt need in the art for a coating compound for a portable electronic apparatus, which makes it possible to implement various color impressions according to the mixing composition of the coating compound and to implement tactile expression according to the expression of exterior texture, and a coating method for the portable electronic apparatus, that also permits the apparatus to be able to withstand a certain amount of shock and not crack the coating. 
       SUMMARY OF THE INVENTION 
       [0012]    An exemplary aspect of the present invention is to provide a coating compound for a portable electronic apparatus, which makes it possible to provide a desired degree of texture with a single coating layer. In addition, a coating method for coating items such as a portable electronic apparatus is described herein. 
         [0013]    Another exemplary aspect of the present invention is to provide a coating compound for a portable electronic apparatus, which allows expression of vivid metallic texture through diffused reflection brightness by using acrylic beads or urethane beads and also allows expression of a color impression like aluminum sanding, and a coating method for the portable electronic apparatus. 
         [0014]    Still another exemplary aspect of the present invention is to provide a coating compound (and coating method) for a portable electronic apparatus that makes it possible to implement various color impressions according to the mixing composition of the coating compound and to implement tactile impressions according to the expression of exterior texture for the portable electronic apparatus. 
         [0015]    According to an exemplary aspect of the present invention, there is provided a coating compound for a portable electronic apparatus, which includes a housing and the coating compound coated onto the housing, and in which a bead portion is blended and added to the coating compound and the coating compound is coated onto the housing and then dried, such that convexes and concaves are formed on and in an outer surface of the housing by the bead portion. 
         [0016]    According to another exemplary aspect of the present invention, there is provided a coating method for a portable electronic apparatus onto which a coating compound is to be coated, the method including manufacturing a housing of the portable electronic apparatus by injection, coating the coating compound onto the manufactured housing, drying the coating compound coated onto the housing, and allowing particles of acrylic beads and urethane beads included in the coating compound to protrude from an outer surface of the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]    The above and other exemplary features and advantages of an exemplary embodiment of the present invention will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
           [0018]      FIG. 1  illustrates a state in which a coating compound is coated on a housing according to an exemplary embodiment of the present invention; 
           [0019]      FIG. 2  illustrates a state in which the coating compound coated on the housing is dried according to the exemplary embodiment of the present invention; 
           [0020]      FIG. 3  illustrates a state in which convexes and concaves are formed on and in an outer surface of the housing by a bead portion according to the exemplary embodiment of the present invention; and 
           [0021]      FIG. 4  is a flowchart illustrating a coating method for a portable electronic apparatus according to the exemplary embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    Hereinafter, a coating compound for a portable electronic apparatus according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. Descriptions of well-known functions and constructions may be omitted for clarity and conciseness when their inclusion may obscure appreciation of the claimed subject matter by a person of ordinary skill in the art. In addition, like reference numerals are generally used to refer to like components having the same functions as conventional functions. 
         [0023]    As shown in the examples in  FIGS. 1 through 3 , the portable electronic apparatus  100  includes a housing  110  and a coating compound  120  to which a bead portion  130  is blended and added. The housing  110  is preferably manufactured by injection. The coating compound  120  is preferably coated onto the housing  110  as a single layer. As the coating compound  120  is coated onto the housing  110  and then dried, the bead portion  130  gathers toward an outer surface of the coating compound  120 , thus forming convexes and concaves on and in a surface of the housing  110 . 
         [0024]    As shown in the examples in  FIGS. 1 through 3 , if the housing  110  is injection-manufactured with polycarbonate (PC), which is a plastic material, and acrylonitrile-butadiene-styrene (ABS) resin, a single coating layer is formed by applying the coating compound  120  onto the outer surface of the housing  110 . Since the bead portion  130  is blended and added to the coating compound  120 , uniform texture can be acquired on the outer surface of the housing  110  even if the coating compound  120  is applied as a single layer. 
         [0025]    As shown in  FIGS. 1 through 3 , if the housing  110  includes a metal member, including but in no way limited to magnesium (Mg), aluminium (Al), stainless steel (STS), a primer layer for improving adherence or color matching between the housing  110  and the coating compound  120  is further coated. If the housing  110  is injection-manufactured with a compound of polycarbonate, which is a plastic material, and glassfiber (PC+GF) or polyphthalmide (PPA) for superior physical properties such as shock resistance in spite of small thickness, the primer layer for improving adherence or color matching between the housing  110  and the coating compound  120  is further coated. 
         [0026]    According to an exemplary aspect of the present invention, the coating compound  120  preferably includes at least one or more of polyester polyol, urethane polyol, polybutadiene polyol, and acrylic polyol. 
         [0027]    In addition, the preferable content of the coating compound  120  is substantially 40 to 50% by weight (or wt %). 
         [0028]    Moreover, the coating compound  120  further preferably substantially includes: 0 to 10 wt % of aluminium paste, 0 to 10 wt % of pearl pigment, 0 to 10 wt % of an additive, and 0 to 10 wt % of a color pigment. 
         [0029]    According to another exemplary aspect of the present invention, the coating compound  120  is applied in a state of being included in a solvent. The solvent is prepared by mixing at least two or more, preferably two to four, of xylene, toluene, methanol, ethanol, isoprophylene alcohol, isobutyl alcohol, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, ethyl acetate, and butyl acetate. The content of the solvent is substantially 20 to 50% by weight. The bead portion  130  is made by blending acrylic beads and urethane beads. By coating the coating compound  120  onto the housing  110  and then drying it, the particles of the acrylic beads and the urethane beads that were added to the coating compound  120  protrude from the outer surface of the housing  110 , thus forming a plurality of convex and concave surfaces. The acrylic beads and the urethane beads are generally formed to have a size of about 5 to 20 μm in consideration of spray-line workability and mass production during application of the coating compound  120  onto the housing  110 , and are added to the coating compound  120  preferably after being blended. The acrylic beads and the urethane beads have different textures and chemical physical properties, and thus a composition ratio thereof may vary with the extent to which their physical properties are secured. 
         [0030]    With reference to  FIGS. 1 through 3 , a more detailed description will now be made of the coating compound  120  for the portable electronic apparatus according to an exemplary embodiment of the present invention. 
         [0031]    As shown in  FIG. 1 , the coating compound  120  is applied onto the housing  110  of the portable electronic apparatus. The coating compound  120  includes at least one or more of, for example, polyester polyol, urethane polyol, polybutadiene polyol, and acrylic polyol, and the content thereof is 40 to 50% by weight. When the coating compound  120  is applied onto the housing  110 , it may further include substantially about: 0 to 10 wt % of aluminium paste, 0 to 10 wt % of pearl pigment, 0 to 10 wt % of an additive, and 0 to 10 wt % of a color pigment to represent metallic texture of the housing  110 . The coating compound  120  is coated onto the housing  110  in a state of being included in the solvent which is prepared by mixing at least two or more of xylene, toluene, methanol, ethanol, isoprophylene alcohol, isobutyl alcohol, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, ethyl acetate, and butyl acetate. The preferable content of the solvent is 20 to 50% by weight. The acrylic urethane beads  130  are blended together and added to the coating compound  120  such that colors which are vivid and represent a metallic texture through diffused reflection brightness can be expressed and natural, mineral, warm, and organic impressions can be expressed. The acrylic beads and the urethane beads generally have a size of about 5 to 20 μm in consideration of spray-line workability and mass production during coating of the coating compound  120  onto the housing  110 . These acrylic and urethane beads  130  are added to the coating compound  120  according to their colors and tactile impressions. The acrylic beads and the urethane beads have different textures and chemical physical properties, and thus a composition ratio thereof may vary with the extent to which their physical properties are secured. Accordingly, the coating compound  120  including the foregoing components is applied (coated) onto the injection-manufactured housing  110  and then dried. 
         [0032]    As shown in  FIG. 2 , as the coating compound  120  is dried, the urethane beads  130  and the acrylic beads  130  gather while protruding from the outer surface of the coating compound  120 . As a result, when the coating compound  120  is completely dried, convexes and concaves (i.e. convex and concave surfaces) are formed on and in the outer surface of the housing  110  as shown in  FIG. 3 , thus forming a texture on the outer surface of the housing  110 . 
         [0033]    With reference to the accompanying drawings, a detailed description will now be made of a coating method for the portable electronic apparatus according to the exemplary embodiment of the present invention. 
         [0034]    Exemplary operation of the method of coating according to the present invention is shown in the flowchart of  FIG. 4 . The coating method includes step S 1  of manufacturing the housing  110  for the portable electronic apparatus by injection, step S 2  of coating an exterior of the injection-manufactured housing  110 , step S 3  of drying the coating compound  120  coated onto the housing  110 , and step S 4  in which particles of acrylic/urethane beads included in the coating compound  120  protrude from the outer surface of the housing  110 . 
         [0035]    According to an exemplary aspect of the present invention, if the housing  110  is manufactured with polycarbonate (PC) and acrylonitrile-butadiene-styrene (ABS) resin, the coating compound  120  is directly coated onto the outer surface of the housing  110 . 
         [0036]    According to another exemplary aspect of the present invention if the housing  110  includes a metal member, a compound of polycarbonate and glassfiber (PC+GF), or polyphthalamide (PPA) in step S 1 , then as shown in  FIG. 4 , step S 11  of coating a primer layer for improving adherence or color matching between the housing  110  and the coating compound  120  is further provided. 
         [0037]    According to the present invention, the coating compound  120  includes at least one or more of polyester polyol, urethane polyol, polybutadiene polyol, and acrylic polyol. The preferable content of the coating compound  120  is 40 to 50% by weight. The coating compound  120  preferably includes 0 to 10 wt % of aluminium paste, 0 to 10 wt % of pearl pigment, 0 to 10 wt % of an additive, and 0 to 10 wt % of a color pigment, and the coating compound  120  is applied in a state of being included in a solvent prepared by mixing at least two or more of xylene, toluene, methanol, ethanol, isopropylene alcohol, isobutyl alcohol, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone, ethyl acetate, and butyl acetate. 
         [0038]    Moreover, according to the present invention, the acrylic beads and the urethane beads are blended and added to the coating compound  120  prior to the coating compound  120  being applied and then dried, so that the particles of the acrylic beads and the urethane beads protrude from the outer surface of the housing  110  to form convexes and concaves. 
         [0039]    Accordingly, according to the present invention a single coating layer is coated onto the housing of the portable electronic apparatus to impart texture, thereby providing visual and tactile properties and improving aesthetic quality. Moreover, by forming a desired texture on the outer surface of the housing with single coating, the manufacturing costs can be reduced. Furthermore, the elegance of the portable electronic apparatus can be acquired by applying the coating compound onto a portion of the housing to which a metal material is difficult to apply. 
         [0040]    As is apparent from the foregoing description, according to the present invention, texture can be expressed with a single coating layer, thereby simplifying an assembly process and cutting down the cost of materials. 
         [0041]    Moreover, according to the present invention, by adding acrylic beads or urethane beads to the coating compound, vivid metallic texture can be expressed through diffused reflection brightness and a color impression like aluminum sanding can be achieved, thereby making the exterior design of the portable electronic apparatus more sophisticated and improving the aesthetic quality of the portable electronic apparatus. 
         [0042]    Furthermore, various color impressions can be provided according to the mixing composition of the coating compound and tactile expression can be implemented according to the expression of the exterior texture, thereby providing a more agreeable touch to users and unifying the exterior design of the portable electronic apparatus with metallic texture. 
         [0043]    While the coating compound for the portable electronic apparatus and the coating method for the portable electronic apparatus according to the present invention have been shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.