Electrically conductive coating

• US 3,962,488 A
• Filed: 08/09/1974
• Issued: 06/08/1976
• Est. Priority Date: 08/09/1974
• Status: Expired due to Term

• Current Assignee: PPG Industries Incorporated (Nouryon BV)
• Original Assignee: PPG Industries Incorporated (Nouryon BV)
• Inventors: Gillery, Frank H.
• Primary Examiner(s): Weiffenbach, Cameron K.
• Application Number:
  US05/495,974
• Time in Patent Office: 669 Days
• Field of Search: 117/211, 117/217, 117/221, 117/106 R, 117/107.1, 117/124 T, 117/124 C, 161/192, 161/213, 427/109, 427/126, 427/164, 427/166
• US Class Current: 427/109
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3613 Coatings of type glass/inorganic compound/metal/inorganic compound/metal/other
• CPC Class Codes: C03C 17/3644 the metal being silver
• CPC Class Codes: C03C 17/3649 made of metals other than silver
• CPC Class Codes: C03C 17/3652 the coating stack containing at least one sacrificial layer to protect the metal from oxidation
• CPC Class Codes: C03C 17/3655 the multilayer coating containing at least one conducting layer
• CPC Class Codes: C03C 17/3673 specially adapted for use in heating devices for rear window of vehicles
• CPC Class Codes: C03C 17/3681 the multilayer coating being used in glazing, e.g. windows or windscreens
• CPC Class Codes: C23C 14/083 of refractory metals or yttrium
• CPC Class Codes: C23C 14/18 on other inorganic substrates

Abstract

An optically clear, electrically conductive, transparent coating on a substrate and a method of coating are disclosed. The coating comprises a first transparent layer deposited as TiO_x on the substrate, where x preferably has a value within the range of 1.3 to 1.7, a layer of silver or gold deposited on the first layer, and a third transparent layer deposited as TiO_x on the second layer, where x preferably has a value within the range of 1.3 to 1.7. The coating is deposited under vacuum in a partial pressure of oxygen on a rigid transparent substrate such as glass or a flexible plastic substrate and the resultant coated substrate used in electrically heated windows.

Claims

1. A method of making a coated article comprising:

a. vacuum depositing in a partial pressure of oxygen titanium oxide having the form TiO_x where x is from 1.3 to 1.7 on a substrate to form a transparent film having a thickness of from 200 to 500 Angstroms;

b. vacuum depositing silver or gold on the previously deposited TiO_x film at a rate sufficiently fast to form a transparent continuous metal film having a thickness of from 60 to 250 Angstroms and having a sheet resistance of less than 10 ohms per square, and

c. vacuum depositing in a partial pressure of oxygen titanium oxide having the form TiO_x where x is from 1.3 to 1.7 on the previously deposited metal film to form a transparent film having a thickness of from 200 to 500 Angstroms.

2. The method of claim 1 in which the TiO_x films are deposited from a source of titanium metal.

3. The method of claim 1 in which the partial pressure of oxygen is within the range of 1.0 to 3.0 ×

10^-4 Torr.

4. The method of claim 1 in which the coated article has a luminous transmittance of at least 75 percent.

5. The method of claim 4 in which the coated article has a luminous transmittance of at least 80 percent.

6. The method of claim 1 in which the substrate is selected from the class consisting of rigid transparent materials and flexible plastic materials.

7. The method of claim 6 in which the substrate is glass.

8. The method of claim 6 in which the substrate is polyester.