Process for producing thin transparent gold coatings

• US 6,168,825 B1
• Filed: 11/02/1999
• Issued: 01/02/2001
• Est. Priority Date: 11/02/1998
• Status: Expired due to Fees

• Current Assignee: Gerald S. Jakubowski, James M. Landry, Jerry Vogler, Oʼbrien, Dudley
• Original Assignee: Gerald S. Jakubowski, James M. Landry, Jerry Vogler, Oʼbrien, Dudley
• Inventors: Landry, James M., OʼBrien, Dudley, Vogler, Jerry, Jakubowski, Gerald S.
• Primary Examiner(s): CAMERON, ERMA C
• Application Number:
  US09/432,510
• Time in Patent Office: 427 Days
• Field of Search: 427/421, 427/426, 427/160, 427/162, 427/163.1, 427/164, 427/165, 427/168, 427/368, 427/369
• US Class Current: 427/160
• CPC Class Codes: C03C 17/10 by deposition from the liquid phase
• CPC Class Codes: C03C 17/38 at least one coating being a coating of an organic material
• CPC Class Codes: C03C 2217/255 Au
• CPC Class Codes: C03C 2218/111 by dipping, immersion
• CPC Class Codes: C03C 2218/31 Pre-treatment
• CPC Class Codes: C23C 18/1855 by mechanical pretreatment, e.g. grinding, sanding
• CPC Class Codes: C23C 18/1858 by formation of electrostatic charges, e.g. tribofriction
• CPC Class Codes: C23C 18/1893 with use of organic or inorganic compounds other than metals, first
• CPC Class Codes: C23C 18/285 Sensitising or activating with tin based compound or composition
• CPC Class Codes: C23C 18/44 using reducing agents
• CPC Class Codes: G02B 5/208 for use with infrared or ultraviolet radiation, e.g. for separating visible light from infrared and/or ultraviolet radiation

Abstract

A process for forming a thin blue colored gold deposit, which transmits substantially more visible light than infrared energy. A suitable substrate, usually transparent, is selected and aggressively cleaned to such an extent that water will sheet rather than bead on the surface. The surface is sensitized with a solid phase sensitizing agent such as tin chloride. The surface is either rubbed with a slurry of the solid phase sensitizing agent or it is or it is dipped into an agitated slurry of the agent. Two very dilute reagent solutions are prepared; a reducing solution, and a gold ion containing solution. The reagent solutions are co-mingled and simultaneously projected onto the cleaned surface. The reagent solutions react to form a blue colored gold deposit on the surface. This blue colored deposit passes more visible than infrared energy by a factor of approximately two.

Claims

1. Process of applying a blue coating of gold on a surface of a substrate comprising:

selecting a substrate having a clean surface, said surface being cleaned sufficiently to permit the adhesion of said blue coating of gold to said surface;

applying a solid phase sensitizing material to said clean surface;

forming a liquid mixture of a reducing reagent and a gold ion containing reagent and substantially simultaneously with said forming, applying said liquid mixture to said clean surface; and

allowing said liquid mixture to react on said clean surface and form a substantially transparent blue colored gold deposit on said clean surface.

2. Process of applying a blue coating of gold on a surface of a substrate according to claim 1 wherein the concentration of said gold ion in said gold ion containing reagent is from approximately 0.1 to 1.0 percent by weight.

3. Process of applying a blue coating of gold on a surface of a substrate according to claim 1 wherein said solid phase sensitizing material is tribolically applied to said surface.

4. Process of applying a blue coating of gold on a surface of a substrate according to claim 1 wherein said reducing reagent is supplied to said liquid mixture in stoichiometric excess.

5. Process of applying a blue coating of gold on a surface of a substrate according to claim 1 wherein said gold ion containing reagent has an approximately neutral pH, and said reducing reagent has a pH of between about 8 and 12.

6. Process of applying a thin blue coating of gold on a surface of a substrate according to claim 1 including selecting a glass substrate.

7. Process of applying a blue coating of gold on a surface of a substrate according to claim 1 including selecting a plastic substrate, and said allowing comprises allowing a substantially transparent blue coating of gold to form on said plastic substrate.

8. Process of applying a blue coating of gold on a surface of a substrate according to claim 1 including selecting a polycarbonate substrate.

9. Process of applying a blue coating of gold on a surface of a substrate according to claim 1 including selecting a substantially solid transparent substrate.

11. Process of forming a blue colored deposit of gold on a substrate according to claim 1 including applying a solid phase sensitizing material to said clean surface by dipping said clean surface in a slurry of said solid phase sensitizing material.

10. Process of forming a blue colored deposit of gold on a substrate, said deposit having a transmittance of at least about 40 percent of the incident visible light and less than about 30 percent of the incident infrared energy, said process comprising:

selecting a substantially transparent substrate;

cleaning a surface of said substrate to produce a clean surface, said surface being cleaned sufficiently to prevent water from beading on said clean surface;

tribolically applying a solid phase sensitizing agent to said clean surface to produce a sensitized surface;

preparing a reducing solution of a reducing agent;

preparing a gold ion solution containing from about 0.1 to 1.0 weight percent gold ion;

mixing said gold ion solution with a stoichiometric excess of said reducing solution to form a reactant mixture and substantially simultaneously with said mixing, applying said reactant mixture to said clean surface;

allowing said reactant mixture to react whereby a blue colored gold deposit is formed on said clean surface;

discontinuing allowing said reactant mixture to react before said blue colored gold deposit reaches a thickness of about 300 Angstroms.