Low emissivity film

Abstract

A low emissivity film which comprises: a substrate; and a coating of oxide and metallic films alternately formed on the substrate in a total of (2n+1) layers where n is an integer being equal to or more than 1, with the innermost layer being an oxide film, wherein the oxide film (B) formed on the outer side of the metallic film (A) being most apart from the substrate, has an internal stress which is equal to, or less than 1.1x1010 dyne/cm2.

We claim:  
     
       1. A low emissivity film which comprises: 
       a substrate; and  
       a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of (2n+1) layers where n is an integer being equal to or more than 1, with the layer closest to the substrate being an oxide film, wherein the oxide film (B) formed on the outer side of the metallic film (A) being most remote from the substrate, has an internal stress which is equal to, or less than 1.1×10 10  dyne/cm 2  and is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr, said oxide film (B) having a thickness of 200 to 700 Å and said metallic film having a thickness of 50 to 150 Å.  
     
     
       2. The low emissivity film according to claim  1 , wherein at least one layer of the oxide film except the oxide film (B) has an internal stress, whose value is equal to or less than 1.1×10 10  dyne/cm 2 . 
     
     
       3. The low emissivity film according to claim  1 , wherein the oxide of the oxide film most remote from the substrate of zinc or tin is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr in an amount of at most 10% atomic ratio based on the total amount of metal present. 
     
     
       4. The low emissivity film according to claim  1 , wherein the oxide film (B) is a multi-layer film comprising at least two layers, having a film layer which has an internal stress, whose value is equal to or less than 7.0×10 9  dyne/cm 2  and whose major component is tin oxide. 
     
     
       5. The low emissivity film according to claim  4 , wherein the oxide film layer (B) is a multi-layer film layer having at least a film whose major component is zinc oxide, and a film having an internal stress, whose value is equal to or less than 7.0×10 9  dyne/cm 2 , and whose major component is tin oxide. 
     
     
       6. The low emissivity film according to claim  1 , wherein the oxide film (B) is composed of a single layer or a multi-layer, having at least a layer of which major component is zinc oxide. 
     
     
       7. The low emissivity film according to claim  6 , wherein the layer of said oxide film (B) most remote from the substrate comprises a layer for controlling adhesive strength thereof with a plastic intermediate film for lamination with another substrate. 
     
     
       8. The low emissivity film according to claim  6 , wherein the crystal structure of said zinc oxide is hexagonal, and the value of the diffraction angle 2θ (center of gravity position) of ( 002 ) diffraction line of the hexagonal zinc oxide in X-ray diffraction method using CuKα radiation, is not smaller than 33.88° and not larger than 35.00°. 
     
     
       9. The low emissivity film according to claim  8 , wherein the value of the diffraction angle 2θ (center of gravity position) of ( 002 ) diffraction line of the hexagonal zinc oxide in X-ray diffraction method using CuKα radiation, is not smaller than 34.00° and not larger than 34.88°. 
     
     
       10. A low emissivity film which comprises: 
       a substrate; and  
       a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of (2n+1) layers where n is an integer being equal to or more than 1, with a layer thereof closest to the substrate being an oxide film,  
       wherein the oxide film (B) formed on the side of the metallic film (A) being most remote from the substrate, is a single layer film or a multi-layer film having at least a film whose major component is hexagonal zinc oxide and is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr; and  
       the value of the diffraction angle 2θ (center of gravity position) or ( 002 ) diffraction line of the hexagonal zinc oxide of the low emissivity film in X-ray diffraction method using CuKα radiation, is not smaller than 33.88° and not larger than 35.00° wherein said oxide film (B) has a thickness of 200 to 700 Å and said metallic film has a thickness of 50 to 150 Å.  
     
     
       11. The low emissivity film according to claim  10 , wherein the oxide of the oxide film most remote from the substrate of zinc or tin is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr in an amount of at most 10% atomic ratio based on the total amount of metal present. 
     
     
       12. The low emissivity film according to claim  10 , wherein the layer of said oxide film (B) most remote from the substrate comprises a layer for controlling adhesive strength thereof with a plastic intermediate film for lamination with another substrate. 
     
     
       13. The low emissivity film according to claim  10 , wherein the value of the diffraction angle 2θ (center of gravity position) of ( 002 ) diffraction line of the hexagonal zinc oxide in x-ray diffraction method using CuKα radiation is not smaller than 34.00° and not larger than 34.88°. 
     
     
       14. The low emissivity film according to claim  10 , wherein the metallic film (A) is a metallic film whose major component is Ag. 
     
     
       15. A low emissivity film which comprises: 
       a substrate; and  
       a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of (2n+1) layers where n is an integer being equal to or more than 1, with the layer closest to the substrate being an oxide film,  
       wherein the oxide film (B) formed on the side of the metallic film (a) being most remote from the substrate is a multi-layer and is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr, comprising at least three layers in which a single layer or a plurality of layers, the major component thereof being zinc oxide and a single layer or a plurality of layers, the major component thereof being tin oxide, are alternatively formed, said oxide film (B) having a thickness of 200 to 700 Å and said metallic film having a thickness of 50 to 150 Å, wherein the oxide film (B) formed on the side of the metallic film (A) being most remote from the substrate has an internal stress which is equal to, or less than 1.1×10 10  dyne/cm 2 .  
     
     
       16. The low emissivity film according to claim  15 , wherein the oxide of the oxide film most remote from the substrate of zinc or tin is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr in an amount of at most 10% atomic ratio based on the total amount of metal present. 
     
     
       17. The low emissivity film according to claim  15 , wherein the crystal structure of said zinc oxide is hexagonal, and the value of the diffraction angle 2θ (center of gravity position) of ( 002 ) diffraction line of the hexagonal zinc oxide in X-ray diffraction method using CuKα radiation, is not smaller than 33.88° and not larger than 35.00°. 
     
     
       18. The low emissivity film according to claim  15 , wherein the metallic film (A) is a metallic film whose major component is Ag. 
     
     
       19. The low emissivity film according to claim  15 , wherein the oxide film (B) has a multi-layer film comprising three layers or five layers in which a plurality of layers, the major component thereof being zinc oxide (C), and a single layer or a plurality of layers, the major component thereof tin oxide (D), are alternatively laminated in an order of (C) layer, (D) layer, and (C) layer. 
     
     
       20. The low emissivity film according to claim  15 , wherein the oxide film (B) has a multi-layer film comprising three layers or five layers in which a single layer or a plurality of layers whose major component is zinc oxide (E), and a plurality of layers whose major component is tin oxide (F), are alternatively laminated in an order of (F) layer, (E) layer, and (F) layer. 
     
     
       21. The low emissivity film according to claim  15 , wherein at least one layer of the oxide films except the oxide film (B) is a multi-layer film having at least a layer whose major component is zinc oxide and a layer whose major component is tin oxide. 
     
     
       22. A low emissivity film which comprises: 
       a substrate; and  
       a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of (2n+1) layers where n is an integer being equal to or more than 1, with the layer closest to the substrate being an oxide film,  
       wherein the oxide film (B) being most remote from the substrate is composed of a multi-layer having at least one layer of which major component is zinc oxide, at least one of said layer whose major component is zinc oxide being doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr, said oxide film (B) comprising at least three layers in which a single layer or a plurality of layers, the major component thereof being zinc oxide and a single layer or a plurality of layers, the major component thereof being tin oxide, are alternatively formed, said oxide film (B) having a thickness of 200 to 700 Å and said metallic film having a thickness of 50 to 150 Å, wherein the layer of the oxide film (B) formed on the side of the metallic film (A) being most remote from the substrate whose major component is zinc oxide has an internal stress which is equal to, or less than 1.1×10 10  dyne/cm 2  and  
       wherein the layer of said oxide film (B) most remote from the substrate comprises a layer for controlling adhesive strength thereof with a plastic intermediate film for lamination with another substrate.  
     
     
       23. A low emissivity film which comprises: 
       
         a substrate; and  
       
         a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of  (   2 n+ 1   )  layers where n is an integer being equal to or more than  1 , with the layer closest to the substrate being an oxide film,    
         wherein the oxide film  ( B )  formed on the side of the metallic film  ( a )  being most remote from the substrate is a multi - layer, comprising at least three layers, each layer of which comprises zinc oxide or tin oxide, alternatively formed, said oxide film  ( B )  having a thickness of  200  to  700  Å and said metallic film having a thickness of  50  to  150  Å, wherein the crystal structure of said zinc oxide is hexagonal, and the value of the diffraction angle  2 θ  ( center of gravity position )  of  (   002   )  diffraction line of the hexagonal zinc oxide in X - ray diffraction method using CuKα radiation, is not smaller than  33 . 88 ° and not larger than  35 . 00 °.   
     
     
       24. The low emissivity film according to claim  23 , wherein the oxide of the zinc oxide film most remote from the substrate is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr in an amount of at most  10 %  atomic ratio based on the total amount of metal present.   
     
     
       25. The low emissivity film according to claim  23 , wherein the metallic film ( A )  is a metallic film whose major component is Ag.   
     
     
       26. The low emissivity film according to claim  23 , wherein the oxide film ( B )  has a multi - layer film comprising three layers or five layers in which a plurality of layers, the major component thereof being zinc oxide  ( C ) , and a single layer or a plurality of layers, the major component thereof being tin oxide  ( D ) , are alternatively laminated in an order of  ( C )  layer,  ( D )  layer, and  ( C )  layer.   
     
     
       27. The low emissivity film according to claim  23 , wherein the oxide film ( B )  has a multi - layer film comprising three layers or five layers in which a single layer or a plurality of layers whose major component is zinc oxide  ( E ) , and a plurality of layers whose major component is tin oxide  ( F ) , are alternatively laminated in an order of  ( F )  layer,  ( E )  layer, and  ( F )  layer.   
     
     
       28. The low emissivity film according to claim  23 , wherein at least one layer of the oxide films except the oxide film ( B )  is a multi - layer film having at least a layer whose major component is zinc oxide and a layer whose major component is tin oxide.   
     
     
       29. The low emissivity film according to claim  23 , wherein said oxide film ( B )  comprises three layers, wherein the three layers comprise, respectively, ZnO/SnO   2   /ZnO.   
     
     
       30. The low emissivity film according to claim  23 , wherein said oxide film ( B )  comprises three layers, wherein the three layers comprise, respectively, SnO   2   /ZnO/SnO   2 . 
     
     
       31. The low emissivity film according to claim  23 , wherein said oxide film ( B )  is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr.   
     
     
       32. The low emissivity film according to claim  23 , wherein said oxide film ( B )  formed on the side of the metallic film  ( A )  being most remote from the substrate has an internal stress which is equal to or less than  1 . 1 × 10     10    dyne/cm   2 . 
     
     
       33. A low emissivity film which comprises: 
       
         a substrate; and  
       
         a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of  (   2 n+ 1   )  layers where n is an integer being equal to or more than  1 , with the layer closest to the substrate being an oxide film,    
         wherein the oxide film  ( B )  formed on the side of the metallic film  ( a )  being most remote from the substrate is a multi - layer, comprising at least three layers, each layer of which comprises zinc oxide or tin oxide, alternatively formed, said oxide film  ( B )  having a thickness of  200  to  700  Å and said metallic film having a thickness of  50  to  150  Å, wherein said oxide film  ( B )  formed on the side of the metallic film  ( A )  being most remote from the substrate has an internal stress which is equal to or less than  1 . 1 × 10     10    dyne/cm   2 . 
     
     
       34. The low emissivity film according to claim  33 , wherein the oxide of the zinc oxide film most remote from the substrate is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr in an amount of at most  10 %  atomic ratio based on the total amount of metal present.   
     
     
       35. The low emissivity film according to claim  33 , wherein the metallic film ( A )  is a metallic film whose major component is Ag.   
     
     
       36. The low emissivity film according to claim  33 , wherein the oxide film ( B )  has a multi - layer film comprising three layers or five layers in which a plurality of layers, the major component thereof being zinc oxide  ( C ) , and a single layer or a plurality of layers, the major component thereof being tin oxide  ( D ) , are alternatively laminated in an order of  ( C )  layer,  ( D )  layer, and  ( C )  layer.   
     
     
       37. The low emissivity film according to claim  33 , wherein the oxide film ( B )  has a multi - layer film comprising three layers or five layers in which a single layer or a plurality of layers whose major component is zinc oxide  ( E ) , and a plurality of layers whose major component is tin oxide  ( F ) , are alternatively laminated in an order of  ( F )  layer,  ( E )  layer, and  ( F )  layer.   
     
     
       38. The low emissivity film according to claim  33 , wherein at least one layer of the oxide films except the oxide film ( B )  is a multi - layer film having at least a layer whose major component is zinc oxide and a layer whose major component is tin oxide.   
     
     
       39. The low emissivity film according to claim  33 , wherein said oxide film ( B )  comprises three layers, wherein the three layers comprise, respectively, ZnO/SnO   2   /ZnO.   
     
     
       40. The low emissivity film according to claim  33 , wherein said oxide film ( B )  comprises three layers, wherein the three layers comprise, respectively, SnO   2   /ZnO/SnO   2 . 
     
     
       41. The low emissivity film according to claim  33 , wherein said oxide film ( B )  is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr.   
     
     
       42. A low emissivity film which comprises: 
       
         a substrate; and  
       
         a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of  (   2 n+ 1   )  layers where n is an integer being equal to or more than  1 , with the layer closest to the substrate being an oxide film,    
         wherein the oxide film  ( B )  being most remote from the substrate is composed of a multi - layer, said oxide film  ( B )  comprising at least three layers, each layer of which comprises zinc oxide or tin oxide, alternatively formed, said oxide film  ( B )  having a thickness of  200  to  700  Å and said metallic film having a thickness of  50  to  150  Å,    
         wherein the layer of said oxide film  ( B )  most remote from the substrate comprises a layer for controlling adhesive strength thereof with a plastic intermediate film for lamination with another substrate,    
         wherein said oxide film  ( B )  formed on the side of the metallic film  ( A )  being most remote from the substrate has an internal stress which is equal to or less than  1 . 1 × 10     10    dyne/cm   2 . 
     
     
       43. The low emissivity film according to claim  42 , wherein said multilayer has at least one layer of which major component is zinc oxide, at least one of said layer whose major component is zinc oxide being doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr. 
     
     
       44. A low emissivity film which comprises: 
       
         a substrate; and  
       
         a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of  (   2 n+ 1   )  layers where n is an integer being equal to or more than  1 , with the layer closest to the substrate being an oxide film,    
         wherein the oxide film  ( B )  formed on the side of the metallic film  ( a )  being most remote from the substrate is a multi - layer, comprising at least three layers, each layer of which comprises zinc oxide or tin oxide, alternatively formed, said oxide film  ( B )  having a thickness of  200  to  700  Å and said metallic film having a thickness of  50  to  150  Å,    
         wherein said oxide film  ( B )  comprises three layers, wherein the three layers comprise, respectively, ZnO/SnO   2   /ZnO.   
     
     
       45. The low emissivity film according to claim  44 , wherein the oxide of the zinc oxide film most remote from the substrate is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr in an amount of at most  10 %  atomic ratio based on the total amount of metal present.   
     
     
       46. The low emissivity film according to claim  44 , wherein the metallic film ( A )  is a metallic film whose major component is Ag.   
     
     
       47. The low emissivity film according to claim  44 , wherein said oxide film ( B )  is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr.   
     
     
       48. A low emissivity film which comprises: 
       
         a substrate; and  
       
         a coating of an oxide of zinc or tin and metallic films alternately formed on the substrate in a total of  (   2 n+ 1   )  layers where n is an integer being equal to or more than  1 , with the layer closest to the substrate being an oxide film,    
         wherein the oxide film  ( B )  formed on the side of the metallic film  ( a )  being most remote from the substrate is a multi - layer, comprising at least three layers, each layer of which comprises zinc oxide or tin oxide, alternatively formed, said oxide film  ( B )  having a thickness of  200  to  700  Å and said metallic film having a thickness of  50  to  150  Å,    
         wherein said oxide film  ( B )  comprises three layers, wherein the three layers comprise, respectively, SnO   2   /ZnO/SnO   2 . 
     
     
       49. The low emissivity film according to claim  48 , wherein the oxide of the zinc oxide film most remote from the substrate is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr in an amount of at most  10 %  atomic ratio based on the total amount of metal present.   
     
     
       50. The low emissivity film according to claim  48 , wherein the metallic film ( A )  is a metallic film whose major component is Ag.   
     
     
       51. The low emissivity film according to claim  48 , wherein said oxide film ( B )  is doped with at least one dopant selected from the group consisting of Al, Si, B, Ti, Sn, Mg and Cr.