APPLYING ELECTROCONDUCTIVE HEATING CIRCUITS TO GLASS

• US 3,772,075 A
• Filed: 07/20/1971
• Issued: 11/13/1973
• Est. Priority Date: 07/01/1969
• Status: Expired due to Term

• Current Assignee: Milton S. Tarnopol, Thomas P. Snyder
• Original Assignee: Milton S. Tarnopol, Thomas P. Snyder
• Inventors: Tarnopol, Milton S., Snyder, Thomas P.
• Primary Examiner(s): Leavitt, Alfred L.
• Assistant Examiner(s): Esposito, M. F.
• Application Number:
  US05/164,264
• Time in Patent Office: 847 Days
• Field of Search: 204/38.41,38.2 117/70,71,124,211,215,217,47,212,45 106/1
• US Class Current: 204/488
• CPC Class Codes: C03C 17/36 at least one coating being a metal
• CPC Class Codes: C03C 17/3607 Coatings of the type glass/inorganic compound/metal
• CPC Class Codes: C03C 17/3649 made of metals other than silver
• CPC Class Codes: C03C 17/3673 specially adapted for use in heating devices for rear window of vehicles
• CPC Class Codes: C03C 17/3684 the multilayer coating being used for decoration purposes
• CPC Class Codes: C03C 2217/452 Glass
• CPC Class Codes: C03C 2217/479 Metals
• CPC Class Codes: C03C 2217/485 Pigments
• CPC Class Codes: C03C 2217/72 Decorative coatings
• CPC Class Codes: C03C 2218/34 Masking
• CPC Class Codes: C23C 18/1608 from pretreatment step, i.e. selective pre-treatment
• CPC Class Codes: C23C 18/1653 Two or more layers with at least one layer obtained by electroless plating and one layer obtained by electroplating
• CPC Class Codes: H05B 2203/017 Manufacturing methods or apparatus for heaters
• CPC Class Codes: H05B 3/84 Heating arrangements specially adapted for transparent or reflecting areas, e.g. for demisting or de-icing windows, mirrors or vehicle windshields

Abstract

Applying a decorative coating or design of electroconductive material to a glass base. When the base is transparent, the resulting article is useful as a readily heated window from which fog and ice can be readily removed on heating. A frit composition having an appropriate coefficient of expansion, an appropriate maturing temperature, and which matures into a rough, porous coating, is applied to a glass sheet surface in the cirucit pattern desired, the sheet is heated and then cooled rapidly to produce a tempered glass sheet having a rough, porous frit coating conforming to the pattern desired for the electroconductive heating circuit, and a conductive metal coating is selectively deposited on the rough, porous frit by electroless plating. The frit may be sensitized by incorporating a minor amount of a sensitizing metal therein or by applying a sensitizing composition.

Claims

2. A method of depositing a pattern of electroconductive material on a trasparent glass base as in claim 1 which comprises the following steps:

3. The method as in claim 2, wherein said sensitizing step is performed between the fusing step and the electroless plating step and comprises treating the fritcoated glass sheet with a sensitizing composition of a metal taken from the class of sensitizing metals consisting of cuprous copper, stannous tin, nickel, palladium and mixtures thereof.

4. sensitizing said rough, porous frit,

5. The method as in claim 4, wherein said sensitizing metal is incorporated in the form of a soluble compound of said sensitizing metal.

6. applying a protective coating of electrical insulator material to the metallic coating so formed by electropainting.

7. The method as in claim 4, further including the step of applying to said surface a mild, acidic, etching solution that does not harm the transparent glass base but that reacts with said frit for sufficient time to increase the number of free atoms of said sensitizing metal that is exposed but insufficient time to remove said frit completely after said rapid cooling step and before said exposure to said electroless bath.

8. The method as in claim 1, wherein said finely divided sensitized ceramic frit is applied along a series of elongated grooves previously formed along the surface area of said transparent glass sheet.