Patent Publication Number: US-2010119842-A1

Title: Injection preform plastic having surface effect of metallic appearance

Description:
CLAIM OF PRIORITY 
     This application claims priority to application entitled “Injection Preform Plastic Having Surface Effect of Metallic Appearance” filed with the Korean Intellectual Property Office on Nov. 12, 2008 and assigned Serial No. 10-2008-0112073, the contents of which are incorporated herein by reference in its entirety. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a synthetic-resin molded product for the replacement of metal materials and application of a hair-line metallic texture by mold discharge corrosion. More particularly, the present invention relates to an injection preform providing a metallic texture and a fabrication method thereof. 
     2. Description of the Related Art 
     Generally, “a portable communication device” refers to a device with which the user can wirelessly communicate with another party. The portable communication device typically includes a hand-held phone (HHP), a cordless telephone generation  2  (CT-2) cellular phone, a digital phone, a personal communications service (PCS) phone, a personal digital assistant (PDA), etc., and is divided into various types based on the external shape of the device. For example, according to the external shape, types of a mobile terminal are divided into a bar-type, a flip-type, or a folder-type mobile terminal. The above enumerated conventional portable terminals necessarily include an antenna device, a data input/output device, and a data transmitting/receiving device. Of course, the data input device generally employs a keypad by which data can be input through finger-pressing of a screen and/or buttons. 
     Also, the portable communication devices generally include a synthetic resin outer case. Synthetic resin has been used in the replacement of metal materials in fields where metal materials have been conventionally used. Due to the mechanical property of synthetic resins, such as strength, being similar to or better than that of metal materials, their popularity has increased. Especially, as synthetic resin has can be easily changed and is light-weight, compared to metal materials, and thus its application range has been gradually expanded. In addition, a synthetic-resin molded product has the characteristic of high surface gloss. 
     Meanwhile, a synthetic resin material having the above-mentioned characteristics can be applied to various products in the replacement of metal materials due to its advantages in terms of strength and light-weight. However, while synthetic resin has the aforementioned advantages, there is a disadvantage in that synthetic resin has a texture that is poorer than that of metal materials. 
     Accordingly, in an attempt to bypass the disadvantage regarding the texture of the synthetic resin on the surface of the synthetic resin material and the metal material, in the conventional art a hair-line metallic texture, which is generally referred to in the art as a “hair-line” was applied by mold discharge corrosion. Herein, a metallic texture is referred to as a hair-line. Note that the term, “mold discharge corrosion”, indicates a process of forming various patterns on a surface of an injection preform by corroding a surface of an electrode by heat due to a discharge, electronic or mechanical power, which belongs to a conventional art. 
     However, such formation of the hair-line on the metal material cannot meet the customer&#39;s demand for various patterns due to the limited changeable range of the hair-line patterns, and also there are limitations in applying the hair-line to the exterior of a communication device, because the hair-line can reduce/adversely affect the performance of an antenna. 
     Also, there is a disadvantage in that after the injection of the synthetic resin material, the finishing cannot be perfectly completed. 
     In order to overcome the aforementioned disadvantages, there is a long-felt need in the art to coat the surface of the synthetic resin material and the metal material with a thin film primer. 
     SUMMARY OF THE INVENTION 
     Accordingly, the present invention provides an injection preform providing a metallic texture and a fabrication method thereof, in which on the surface of an injection substrate, a thin film primer coating layer is formed to express a metallic texture formed with various patterns and to preserve the texture on the surface of the injection substrate. The injection preform according to the present invention is freely applicable to the exterior of a variety of products, and thus, improves the exterior appearance of products and meets the consumer demand for products with a variety of different textures. Also, it is possible to secure the reliability and mass production of products having at least the aforementioned advantages via the injection preform of the present invention. 
     Also, the present invention provides an injection preform providing a metallic texture and a fabrication method thereof, in which a non-conductive metal-deposited layer is formed on the surface of the injection substrate, so as not to have an impact on the performance of the antenna provided in the product. 
     In accordance with an exemplary aspect of the present invention, there is provided an injection preform providing a metallic texture, the injection preform including: an injection substrate having a surface on which various patterns are formed by mold discharge corrosion; a thin film primer coating layer, which is formed on the surface of the injection substrate for increasing reflectivity of the surface of the injection substrate, so that the thin film primer coating layer expresses a metallic texture with the various patterns while preserving surface texture of the injection substrate; a non-conductive metal-deposited layer deposited on a surface of the thin film primer coating layer; a color coating layer formed on a surface of the non-conductive metal-deposited layer; and a clear layer formed on a surface of the color coating layer. 
     Also, the thin film primer coating layer may include an oligomer, a monomer, an initiator, a leveling agent, and a solvent. 
     Also, the thin film primer coating layer preferably has a non-volatile content of 17.6%, which is generally about one third of a non-volatile content (48.6%) of an existing conventional injection preform. 
     Also, a component of the oligomer preferably includes a hard-type urethane acrylate or soft-type urethane acrylate. 
     Also, in the component of the oligomer, a content of the hard-type urethane acrylate may comprise about 7%, which is higher than a typical content (4.5%) of an existing conventional injection preform, and a content of the soft-type urethane acrylate may comprise about 1.5%, which is lower than a typical content (21%) of the existing conventional injection preform. 
     Also, the non-conductive metal-deposited layer preferably includes a tin (Sn) deposited layer. 
     Also, the injection substrate preferably includes one of acryl, polycarbonate (PC), and Polyethylene terephthalate (PET). 
     Also, the clear layer preferably includes an ultraviolet (UV) coated layer. 
     In accordance with another exemplary aspect of the present invention, there is provided a method of fabricating an injection preform with a metallic texture, the method including the steps of: forming various patterns on an injection substrate by mold discharge corrosion; forming a thin film primer coating layer on a surface of the injection substrate, the thin film primer coating layer for showing a metallic texture with the various patterns while preserving surface texture of the injection substrate, by increasing reflectivity of the surface of the injection substrate; forming a non-conductive metal-deposited layer on a surface of the thin film primer coating layer; forming a color coating layer on a surface of the non-conductive metal-deposited layer; and forming a clear layer on a surface of the color coating layer. 
     Also, the thin film primer coating layer preferably includes an oligomer, a monomer, an initiator, a leveling agent, and a solvent. 
     Also, the thin film primer coating layer preferably has a non-volatile content of substantially 17.6%, which is about one third of a non-volatile content (48.6%) of an existing conventional injection preform. 
     Also, a component of the oligomer preferably includes a hard-type urethane acrylate or soft-type urethane acrylate. 
     Also, in the component of the oligomer, a content of the hard-type urethane acrylate is 7%, which is typically higher than a content (4.5%) of an existing conventional injection preform, and a content of the soft-type urethane acrylate is substantially 1.5%, which is typically lower than a content (21%) of the existing conventional injection preform. 
     Also, the non-conductive metal-deposited layer preferably includes a tin (Sn) deposited layer. 
     Also, the injection substrate preferably includes acryl, polycarbonate (PC), and Polyethylene terephthalate (PET). 
     Also, the clear layer preferably includes a UV layer. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and other exemplary features, aspects, and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a plan view illustrating an injection preform providing a metallic texture, according to an exemplary embodiment of the present invention; 
         FIG. 2  is an enlarged cross-sectional view of part A as shown in  FIG. 1 ; and 
         FIG. 3  is a flow chart illustrating exemplary steps of a method of fabricating an injection preform providing a metallic texture, according to an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following examples are illustrative only, and the scope of the present invention is not limited to the illustrative examples shown and described. Those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the spirit of the invention and the scope of the appended claims. 
     As shown in  FIGS. 1 and 2 , an injection preform  10  with a metallic texture includes an injection substrate  11 , a thin film primer coating layer  12 , a non-conductive metal-deposited layer  13 , a color coating layer  14 , and a clear layer  15 . In this example, these layers are successively directly deposited one upon another, however it is possible that there could be additional intervening layers thereon or there between. 
     On the surface of the injection substrate  11 , various patterns with a metallic texture (hair-line) are formed by mold discharge corrosion. 
     The thin film primer coating layer  12  is preferably formed on the surface of the injection substrate  11 , which increases reflectivity of the surface of the injection substrate  11  to express the metallic texture with various patterns and to preserve the surface texture of the injection substrate. 
     The non-conductive metal-deposited layer  13  is preferably deposited on the surface of the thin film primer coating layer  12  so as not to have an influence on the performance of the antenna provided in the product. 
     The color coating layer  14  is preferably formed on the surface of the non-conductive metal-deposited layer  13  so as to further enhance the metallic texture of the injection substrate  11 . 
     The clear layer  15  is preferably formed on the surface of the color coating layer  14  so as to protect the coating layers. 
     The thin film primer coating layer  12  preferably includes an oligomer, a monomer, an initiator, a leveling agent, and a solvent. 
     The thin film primer coating layer  12  has a nonvolatile content of substantially 17.6%, which is about one third of that (48.6%) of a conventional injection preform. 
     The component of the oligomer preferably includes a hard-type urethane acrylate or soft-type urethane acrylate. Herein, the content of the hard-type urethane acrylate is substantially 7%, which is higher than that (4.5%) of the conventional injection preform, and the content of the soft-type urethane acrylate is substantially 1.5%, which is lower than that (typically 21%) of the conventional injection preform. Meanwhile, the non-conductive metal-deposited layer  13  preferably includes a tin (Sn) deposited layer. 
     Note that the component of the oligomer preferably includes both a hard-type urethane acrylate and soft-type urethane acrylate in the present invention to enhance the expression of the metallic texture, and preserve the surface texture of the injection substrate. 
     The injection substrate  11  preferably includes acryl, PC, and PET, and the clear layer  15  includes a UV layer. 
     Hereinafter, the operation of an exemplary process of the injection preform providing a metallic texture, according to a preferred exemplary embodiment of the present invention, as configured above, will be described in more detail with reference to  FIGS. 1 and 2 . 
     As shown in  FIGS. 1 and 2 , in the injection preform  10  with a metallic texture, in which various patterns with a metallic texture (hair-line) are formed on the surface of the injection substrate  11  by mold discharge corrosion, and then the thin film primer coating layer  12  is formed on the surface of the injection substrate  11 , the thin film primer coating layer  12  being for providing a metallic texture with various patterns and preserving the surface texture of the injection substrate  11  by increasing reflectivity of the injection substrate  11 . 
     On the surface of the thin film primer coating layer  12 , the non-conductive metal-deposited layer  13  is preferably formed, on the surface of the non-conductive metal-deposited layer  13 , the color coating layer  14  is preferably formed, and on the surface of the color coating layer  14 , the clear layer  15  is preferably formed. 
     The thin film primer coating layer  12 , when formed, improves the finishing following the injection molding of the injection substrate  11 , and also enhances the expression of the metallic texture, and preserves the surface texture of the injection substrate by increasing the reflectivity. 
     Herein, the injection substrate  11  includes acryl, PC, and PET, and the clear layer  15  includes a UV layer. 
     The thin film primer coating layer  12  includes an oligomer, a monomer, an initiator, a leveling agent, and a solvent, and its coating material composition is noted in Table 1. 
     Also, as noted in Table 1, the thin film primer coating layer  12  has a non-volatile content of substantially 17.6%, which is about one third of that (substantially 48.6%) of the conventional injection preform. 
     Also, the component of the oligomer includes a hard-type urethane acrylate or soft-type urethane acrylate. Herein, the content of the hard-type urethane acrylate is substantially 7%, which is higher than that (4.5%) of the conventional injection preform, and the content of the soft-type urethane acrylate is substantially 1.5%, which is lower than that (21%) of the conventional injection preform. 
     Also, the content of the monomer is substantially 3.5%, which is lower than that (10.5%) of the conventional injection preform. 
     
       
         
           
               
             
               
                 TABLE 1 
               
             
            
               
                   
               
               
                 Thin-Film Primer Composition 
               
            
           
           
               
               
               
               
               
            
               
                 Composition 
                 Component 
                 Prior Art 
                 Improved 
                 Remarks 
               
               
                   
               
               
                 oligomer 
                 hexafunctional 
                 4.5%  
                   7% 
                 hard type 
               
               
                   
                 urethane acrylate 
               
               
                   
                 bifunctional urethane 
                 21% 
                 1.5% 
                 soft type 
               
               
                   
                 acrylate 
               
               
                 monomer 
                 bifunctional monomer 
                 10.5%   
                 3.5% 
               
               
                   
                 multifunctional 
                 10.5%   
                 3.5% 
               
               
                   
                 monomer 
               
               
                 solvent 
                 hydro carbon 
                 25% 
                  40% 
               
               
                   
                 ester 
                 25% 
                  40% 
               
               
                   
                 ketone 
                 1.4%  
                 2.4% 
               
               
                 additive 
                 photoinitiator 
                  2% 
                   2% 
               
               
                   
                 leveling agent 
                 0.1%  
                 0.1% 
               
               
                   
                 matting agent 
                   
               
            
           
           
               
               
               
               
            
               
                 Total 
                 100%  
                 100%  
                   
               
               
                 NV (Non-Volatile) content 
                 48.6%   
                 17.6%  
               
               
                   
               
            
           
         
       
     
     Hereinafter, a method of fabricating the injection preform providing a metallic texture, according to a preferred exemplary embodiment of the present invention, as configured above, will be described in more detail with reference to  FIG. 3 . 
     Referring to the flowchart in  FIG. 3 , in a fabrication method of the injection preform providing a metallic texture, on an injection substrate  11 , various patterns of hair-lines are formed by mold discharge corrosion (S 1 ). 
     Then, on the surface of the injection substrate  11 , a thin film primer coating layer  12  is formed (S 2 ), such that the thin-film primer coating layer  12  for providing a metallic texture with various patterns and preserving the surface texture of the injection substrate  11  by increasing reflectivity. 
     Then, on the surface of the thin-film primer coating layer  12 , a non-conductive metal-deposited layer  13  including a tin (Sn) deposited layer is formed (S 3 ). 
     Subsequently, on the surface of the non-conductive metal-deposited layer  13  formed, a color coating layer  14  is formed so as to further enhance the metallic texture of the injection substrate  11  (S 4 ). 
     Finally, on the surface of the color coating layer  14 , a clear layer  15  including a UV layer is formed so as to protect the coating layers of the injection substrate  11  (S 5 ). 
     Herein, the injection substrate  11  preferably includes acryl, PC, and PET, and the clear layer  15  preferably includes a UV layer. 
     The thin-film primer coating layer  12  includes an oligomer, a monomer, an initiator, a leveling agent, and a solvent, and its coating material composition is noted in Table 1. 
     Also, as noted in Table 1, the thin-film primer coating layer  12  has a non volatile content of 17.6%, which is about one third of that (48.6%) of the conventional injection preform. 
     In addition, the component of the oligomer preferably includes a hard-type urethane acrylate or soft-type urethane acrylate. Herein, the content of the hard-type urethane acrylate is substantially 7%, which is higher than that (4.5%) of the conventional injection preform, and the content of the soft-type urethane acrylate is substantially 1.5%, which is lower than that (21%) of the conventional injection preform. 
     Also, the content of the monomer is substantially 3.5%, which is lower than that (10.5%) of the conventional injection preform. 
     While the injection preform providing a metallic texture and a fabrication method thereof, according to the present invention, have been shown and described with reference to certain exemplary embodiments and drawings, 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.