Transparent substrate coated with a silver layer

Abstract

A transparent substrate carrying a coating stack which has undergone a bending or tempering type of heat treatment and a method of manufacturing this product, the coating stack comprising at least one metallic coating layer comprising silver or a silver alloy characterized in that before the said heat treatment, each metallic coating layer is in contact with two non-absorbent transparent dielectric coating layers, each comprising a sub-layer based on a partially oxidized combination of two metals. The product in accordance with the invention is intended for incorporation in a laminated glazing, particularly to form a vehicle windshield.

1 . A transparent substrate carrying a coating stack including at least one metallic coating layer including silver or a silver alloy, each metallic coating layer being in contact with two non-absorbent the transparent dielectric coating layers, the coated substrate being adapted to withstand a bending of tempering type of heat treatment, wherein prior to such heat treatment, each of the dielectric coating layers includes a sub-layer based on a partially but not totally oxidized combination of at least two metals.  
     
     
         2 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein one of the said two metals is Ni.  
     
     
         3 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein one of the said two metals is Cr.  
     
     
         4 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein the said combination of two metals is based on Ni and Cr.  
     
     
         5 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein at least one metallic coating layer of the said coating stack is in contact with at least an underlying sub-layer of an oxide of a metal selected from Ti, Ta, Nb and Sn.  
     
     
         6 . The transparent substrate carrying a coating stack in accordance with  claim 5 , wherein at least the sub-layer based on a partially oxidized combination of two metals which is closest to the substrate is in contact with an underlying sub-layer of an oxide of titanium.  
     
     
         7 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein the dielectric coating layer positioned between the substrate and the first metallic coating layer includes sub-layers of metal oxides or of oxides of combinations of metals.  
     
     
         8 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein at least one of the two non-absorbent transparent dielectric coating layers includes a sub-layer of at least one nitride.  
     
     
         9 . The transparent substrate carrying a coating stack in accordance with  claim 8 , wherein at least one nitride is a nitride of Si, Al, or a combination of these elements.  
     
     
         10 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein the at least one metallic coating layer is selected from the group consisting of silver, a combination of silver and platinum, a combination of silver and palladium, and a combination of silver, platinum and palladium.  
     
     
         11 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein the coating stack contains a single metallic coating layer.  
     
     
         12 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein the optical thickness of the dielectric coating layer closest to the substrate is between 50 and 90 nm, that of the other dielectric coating layer is between 63 and 110 nm, that of the sub-layers based on a combination of two metals is between 3 and 24 nm and the geometrical thickness of the metallic coating layer is between 8 and 15 nm.  
     
     
         13 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein after a tempering or bending type heat treatment the substrate has a haze of less than 0.3%.  
     
     
         14 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein after a tempering or bending type heat treatment the substrate has an emissivity of less than 0.08.  
     
     
         15 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein following a tempering or bending type heat treatment the luminous transmittance of the substrate under Illuminant A varies by less than 10% with respect to its value prior to the tempering or bending type heat treatment.  
     
     
         16 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein following a tempering or bending type heat treatment its color purity in reflection varies by less than 5% with respect to its value prior to the tempering or bending type heat treatment.  
     
     
         17 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein following a tempering or bending type heat treatment the dominant wavelength in reflection varies by less than 3 nm with respect to its value prior to the tempering or bending type heat treatment.  
     
     
         18 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein following a tempering or bending type heat treatment the luminous transmittance of the substrate under Illuminant A varies by less than 10%, its color purity in reflection varies by less than 5% and its dominant wavelength in reflection varies by less than 3 nm with respect to the values prior to the tempering or bending type heat treatment.  
     
     
         19 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein the coating stack includes, in order, the transparent substrate, a first non-absorbent transparent dielectric coating layer, a first metallic coating layer, an intermediate non-absorbent transparent dielectric coating layer, a second metallic coating layer and a third non-absorbent transparent dielectric coating layer.  
     
     
         20 . The transparent substrate carrying a coating stack in accordance with  claim 19 , wherein the optical thickness of the dielectric coating layer closest to the substrate is between 50 and 80 nm, that of the dielectric coating layer spaced furthest from the substrate is between 16 and 63 nm, that of the intermediate dielectric coating layer is between 16 and 163 nm, that of the sub-layers based on a composition of two metals is between 3 and 24 nm and the geometrical thickness of the metallic coating layers is between 8 and 15 nm.  
     
     
         21 . The transparent substrate carrying a coating stack in accordance with  claim 1 , wherein after a tempering or bending type of heat treatment the substrate has a haze of less than 0.5% and a TLA greater than 76%.  
     
     
         22 . A multiple glazing including a coated substrate in accordance with  claim 1 .  
     
     
         23 . A laminated glazing including a coated substrate in accordance with  claim 1 .  
     
     
         24 . A vehicle windshield including a coated substrate in accordance with  claim 1 .  
     
     
         25 . A method of manufacturing a the transparent substrate carrying a coating stack in accordance with  claim 1 , wherein at least one metallic coating layer is sputter deposited in an oxidizing atmosphere.  
     
     
         26 . The method in accordance with  claim 25 , wherein the said atmosphere includes less than 10% oxygen.  
     
     
         27 . The method in accordance with  claim 25 , wherein the said atmosphere includes 3 to 7% oxygen.  
     
     
         28 . A glass substrate carrying a coating stack including, in order from the glass substrate: 
 a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of at least two metals;    a metallic coating layer selected from the group consisting of silver and silver alloys;    a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of at least two metals.    
     
     
         29 . A glass substrate carrying a coating stack which includes, in order from the glass substrate: 
 a non-absorbent transparent coating layer including a layer of an oxide of titanium and an overlying layer of a partially but not totally oxidized combination of Ni and Cr;    a metallic coating layer selected from the group consisting of silver and silver alloys;    a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of Ni and Cr and an overlying layer of a nitride selected from the group consisting of nitrides of silicon, nitrides of aluminum and mixed nitrides of silicon and aluminum.    
     
     
         30 . A glass substrate carrying a coating stack including, in order from the glass substrate: 
 a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of at least two metals;    a metallic coating layer selected from the group consisting of silver and silver alloys;    a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of at least two metals;    a metallic coating layer selected from the group consisting of silver and silver alloys;    a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of at least two metals.    
     
     
         31 . The glass substrate carrying a coating stack in accordance with  claim 30 , in which at least one of the layers which includes a partially oxidized combination of at least two metals includes Ni.  
     
     
         32 . The glass substrate carrying a coating stack in accordance with  claim 30 , in which at least one of the layers which includes a partially but not totally oxidized combination of at least two metals includes Cr.  
     
     
         33 . The glass substrate carrying a coating stack in accordance with  claim 30 , in which at least one of the layers which includes a partially but not totally oxidized combination of at least two metals includes Ni and Cr.  
     
     
         34 . The glass substrate carrying a coating stack in accordance with  claim 30 , in which at least one of the layers which includes a partially but not totally oxidized combination of at least two metals is a sub-layer of its non-absorbent transparent coating layer.  
     
     
         35 . The glass substrate carrying a coating stack in accordance with  claim 30 , in which at least one of the layers which includes a partially but not totally oxidized combination of at least two metals is partially oxidized across its entire thickness.  
     
     
         36 . The glass substrate having a haze of less than 0.5% including a glass substrate in accordance with  claim 30  which has been subjected to a heat treatment selected from bending and tempering.  
     
     
         37 . The glass substrate having an emissivity of less than 0.08 including a glass substrate in accordance with  claim 30  which has been subjected to a heat treatment selected from bending and tempering.  
     
     
         38 . A glass substrate carrying a coating which includes, in order from the glass substrate: 
 a non-absorbent transparent coating layer including a layer of an oxide of titanium and an overlying layer of a partially but not totally oxidized combination of Ni and Cr;    a metallic coating layer selected from the group consisting of silver and silver alloys;    a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of Ni and Cr;    a metallic coating layer selected from the group consisting of silver and silver alloys;    a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of Ni and Cr and an overlying layer of a nitride selected from the group consisting of nitrides of silicon, nitrides of aluminum and mixed nitrides of silicon and aluminum.    
     
     
         39 . A glass substrate carrying a coating stack including, in order from the glass substrate: 
 a non-absorbent transparent coating layer including a layer of an oxide of titanium and an overlying layer of a partially but not totally oxidized combination of at least two metals;    a metallic coating layer selected from the group consisting of silver and silver alloys; and    a non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of at least two metals.    
     
     
         40 . The glass substrate carrying a coating stack in accordance with  claim 39 , in which the coating stack further includes: 
 a second metallic coating layer selected from the group consisting of silver and silver alloys; and    a third non-absorbent transparent coating layer including a layer of a partially but not totally oxidized combination of at least two metals.    
     
     
         41 . A transparent substrate carrying a coating stack, comprising: 
 at least one metallic coating layer including silver or a silver alloy, each metallic coating layer being in contact with two non-absorbent transparent dielectric coating layers, the coated substrate being adapted to withstand a bending or tempering type of heat treatment, wherein prior to such heat treatment, each of the dielectric coating layers includes a sub-layer based on a partially oxidized combination of two metals.