Patent Publication Number: US-6036826-A

Title: Titanium electrodeposition drum

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an titaniumi electrodeposition drum in a copper foil manufacturing machine for producing a copper foil. 
     Electrodeposition drums for electrolytically deposing a copper foil having a uniform and smooth surface at a constant thickness are known. Currently, in many cases, a titanium plate that is superior in corrosion-resistance against electrolyte liquid is attached on a surface of an inner drum and a copper foil having a uniform and smooth surface and a constant thickness is formed on an outer circumferential surface of titanium plate. 
     In general, the titanium plate is attached on an outer circumferential portion of the inner drum, which is formed of soft steel or stainless steel, and an electric application is effected through the outer circumferential portion. 
     SUMMARY OF THE PRESENT INVENTION 
     The present inventors have studied the possibility that, if conductivity on the inner drum side is good, it is unnecessary to improve the conductivity of the titanium plate, and if contactability between the titanium plate and the inner drum is kept well, a desired constant thickness copper foil having a uniform and smooth surface may be formed. A titanium electrodeposition drum in which an inner side of a titanium plate was lined with a copper plate or the like was produced for tests by the present inventors. Furthermore, in order to obtain an effective electrodeposition effect by further increasing an electric supply, a copper plate or the like was additionally provided on right and left side walls or an intermediate reinforcement plate of the inner drum. Such electrodeposition drums were made and the tests were repeated to reduce the present invention to practice. 
     According to a first aspect of the invention, there is provided a titanium electrodeposition drum in which a titanium plate is provided on an outer circumferential surface of an outer circumferential plate of an inner drum, characterized in that a circumferential copper system plate such as a copper plate or a copper alloy plate is interposed between an outer circumferential surface of the outer circumferential plate of the inner drum and an inner circumferential surface of a titanium plate under an intimate contact condition on each of said upper and lower surfaces of the circumferential copper system plate. 
     Also, in the titanium electrodeposition drum according to a first aspect of the invention, side copper system plates such as copper plates or copper alloy plates are provided on outer surfaces of right and left side wall plates of the inner drum, and the side copper plates and the circumferential copper system plate are provided close to or integrally with each other under a conductive condition. 
     Also, in the titanium electrodeposition drum according to the first and second aspects of the invention, an intermediate copper system plate such as a copper plate or a copper alloy plate is provided on an intermediate reinforcement plate of the inner drum, and the intermediate copper system plate and the circumferential copper system plate are provided close to or integrally with each other in a conductive condition. 
     A preferred embodiment of the present invention will briefly be described as follows. 
     According to the first aspect of the invention, linear expansion coefficients of the copper alloy such as copper, brass, titanium and iron are given as follows: 
     
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titanium         8.41 × 10.sup.-6 (20° C.)                   
iron             11.76 × 10.sup.-6 (20° C.)                  
copper           16.5 × 10.sup.-6 (20° C.)                   
brass            20 to 21 × 10.sup.-6 (20° C.)               
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     As described above, the copper system plate expands 2 to 2.5 times more than the titanium. Accordingly, the circumferential copper plate 3a is adhered to the inner circumferential surface of the titanium plate 2 by the temperature increase during the manufacture. The contactability between the titanium plate 2 and the circumferential copper plate 3a is enhanced. 
     The electric resistances of the four components are as follows: 
     
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titanium       55 (20 ° C. μ Ω · cm)             
iron           9.71 (20° C. μ Ω · cm)            
copper         1.67 (20° C. μ Ω · cm)            
brass          3.6 to 3.7 (20° C. μ Ω · cm)      
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     As described above, the copper system plate is superior in conductivity, e.g., several tens of times or more than the titanium. Thus, if the circumferential copper system plate 3a that is superior in conductivity is lined under an intimate contact condition on the inside of the titanium plate 2 by utilizing its relatively high linear expansion coefficient, it is possible that the insufficiency of the conductivity of the titanium plate 2 would be expected to be compensated. 
     According to this synergetic effect, foil having the constant thickness and having the uniform and smooth surface over the entire range is produced, and at the same time, it is possible to provide a titanium electrodeposition drum for producing on the surface of the titanium plate foil of superior quality without generation of any local electric resistance heat that causes trouble. 
     According to the second aspect of the invention, the side copper system plates 3b formed on the outer surfaces of the right and left side walls 4 of the inner drum b are provided close to or integrally with the circumferential copper system plate 3a formed on the inside of the titanium plate 2 under a conductive condition. The electric supply to the circumferential copper system plate 3a by the side copper system plates 3b is increased. It is possible to improve the effect of the first aspect in the titanium electrodeposition drum a. 
     According to the third aspect of the invention, the intermediate copper system plate 3c formed on the intermediate reinforcement plate 5 is also provided close to or integrally with the circumferential copper system plate 3a. It is possible to provide the titanium electrodeposition drum in a way which will obtain the electric supply to the titanium plate 2 as desired. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the accompanying drawings: 
     FIG. 1 is an illustration of a copper foil manufacturing machine; 
     FIG. 2 is a longitudinal sectional view showing a primary part of an embodiment in which side copper system plates are provided close to a circumferential copper system plate; 
     FIG. 3 is a longitudinal sectional view showing a primary part of an embodiment in which side copper system plates are provided integrally with a circumferential copper system plate; 
     FIG. 4 is a longitudinal sectional view of a type of drum having an intermediate reinforcement plate provided with the intermediate copper system plate in an intermediate portion, in which hatching for parts other than the copper system plates is omitted; and 
     FIG. 5 is a cross-sectional view showing a linear weld portion shown in FIG. 4 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An embodiment of the present invention will now be described with reference to the accompanying drawings. 
     In a titanium electrodeposition drum a shown in the drawings, a titanium plate 2 is provided on an outer circumferential surface 1a of an outer circumferential plate 1 of an inner drum b. A circumferential copper system plate 3a such as a copper plate or a copper alloy plate is interposed between the outer circumferential surface 1a of the outer circumferential plate 1 of the inner drum b and an inner circumferential surface 2a of the titanium plate 2 with its upper and lower surfaces in intimate contact with the outer circumferential surface 1a and the inner circumferential surface 2a. Side copper plates 3b such as copper plates or copper alloy plates are provided on outer surfaces of right and left side wall plates 4 of the inner drum b. The side copper plates 3b and the circumferential copper plate 3a are provided close to or integrally with each other under a conductive condition. An intermediate copper system plate 3c such as a copper plate or a copper alloy plate is provided on an intermediate reinforcement plate 5 of the inner drum b. The intermediate copper system plate 3c and the circumferential copper plates 3a are provided close to or integrally with each other under a conductive condition. 
     FIG. 1 is an illustration of a copper manufacturing machine A including a conductive line 6, an electrode 7, a power source 8, a rotary shaft 9, a copper sleeve provided around an outer circumference of the rotary shaft 9 and a conductive bearing 10. 
     FIG. 2 is a view showing an embodiment in which the side copper plates 3b are provided close to the circumferential copper system plate 3a. FIG. 3 is a view showing an embodiment in which the side copper plates 3b are provided integrally with the circumferential copper system plate 3a. Reference numeral 13 denotes a welded portion. 
     FIG. 4 is a view showing an embodiment in which the intermediate copper system plate 3c is provided on the intermediate reinforcement plate 5, and outer edge portions of the intermediate copper system plate 3c are formed integrally with the circumferential copper system plate 3a under the conductive condition. As shown in an enlarged view of FIG. 5, a horizontal ring-shaped flange 3c&#39; is formed integrally with the outer edge of the intermediate copper system plate 3c. The flange 3c&#39; and the circumferential copper system plate 3a are formed integrally with each other through a line welded portion 12. 
     The copper system plate is superior in heat conductivity to the titanium plate 2 as follows: 
     copper: 0.94 (20° C.·cal/cm·s·° C.) 
     titanium: 0.037 (20° C.·cal/cm·s·° C.) 
     Accordingly, the above-described provision of the circumferential copper system plate 3a, the side copper system plates 3b and the intermediate copper system plate 3c leads to the improvement in heat conductivity and also exhibits the advantage of preventing the local hot zone. It is thus possible to perform the manufacture of foil having a constant thickness with a smooth surface. 
     One example of a dimension of the electrodeposition drum is given as follows: 
     
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electrodeposition drum                                                    
                    .O slashed.2,300 mm in diameter                       
electrodeposition drum                                                    
                    1,200 mm in width                                     
drum outer circumferential plates 1                                       
                    22 mm in thickness                                    
made of stainless steel or soft iron                                      
titanium plate 2    5 mm in thickness                                     
circumferential copper system                                             
                    4 mm in thickness                                     
plate 3a such as a copper plate or                                        
a copper alloy plate                                                      
side copper system plates 3b                                              
                    5 mm in thickness                                     
such as a copper plate or a                                               
copper alloy plate                                                        
intermediate copper system                                                
                    7 mm in thickness                                     
plate 3c such as a copper plate or                                        
a copper alloy plate                                                      
side wall plates 4 made of                                                
                    22 mm in thickness                                    
stainless steel or soft iron                                              
intermediate reinforcement plate 5                                        
                    22 mm in thickness                                    
made of stainless steel or soft                                           
iron                                                                      
large diameter portion of copper                                          
                    60 mm in thickness                                    
sleeve 3d provided around rotary                                          
shaft 9                                                                   
side titanium plate 11                                                    
                    4 mm in thickness                                     
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     According to a first aspect of the present invention, the copper system plate, which is formed from materials such as copper, copper alloy plate or brass which have superior linear expansion coefficients, is adhered to the inner circumferential surface of the titanium plate. The contactability between the titanium plate and the copper system plate is enhanced. Since the copper system plate is far superior to the titanium plate in conductivity, the insufficiency of conductivity of the titanium plate is compensated for. According to this synergetic effect, the reduction of the insulation preventing effect caused by a skin generation of the surface corrosion layer or the surface oxidized layer is compensated for. The copper foil that is to be continuously produced is manufactured into foil having a constant thickness with a uniform and smooth surface over the full range. In addition, a copper foil that has an excellent quality, and without any generation of electric resistive heat, is produced on the surface of the titanium plate. 
     Also, according to a second aspect of the present invention, the side copper system plates such as copper plates or copper alloy plates are provided on the outer surfaces of the right and left side plates of the inner drum, and the side copper system plates and the circumferential copper system plate are provided close to or integrally with each other under a conductive condition. The electric supply to the circumferential copper system plate by the side copper system plates is increased to further enhance the advantages of the first aspect. 
     Also, according to a third aspect of the present invention, the intermediate copper system plate is provided on the intermediate reinforcement plate of the inner drum, and the intermediate copper system plate and the circumferential copper system plate are provided close to or integrally with each other under a conductive condition. As a result, the electric supply to the titanium plate is increased to thereby further enhance the advantages of the first and second aspects of the present invention. 
     Various details of the invention may be changed without departing from its spirit and scope. Furthermore, the foregoing description of the embodiments according to the present invention is provided for the purpose of illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.