Deposition of silver layer on nonconducting substrate

• US 5,965,204 A
• Filed: 05/04/1998
• Issued: 10/12/1999
• Est. Priority Date: 05/04/1989
• Status: Expired due to Fees

• Current Assignee: Bactiguard AB (Bactiguard Holding AB)
• Original Assignee: AD Tech Holdings Limited
• Inventors: Lundeberg, Thomas, Sodervall, Billy Valter
• Primary Examiner(s): Talbot, Brian K.
• Application Number:
  US09/072,019
• Time in Patent Office: 526 Days
• Field of Search: 427/98, 427/301, 427/304, 427/305, 427/307, 427/405, 427/437, 427/443.1, 427/2.3, 427/2.31, 427/2.28, 106/15.05, 106/1.23, 106/1.27, 424/618, 424/619, 424/648, 604/265, 604/328
• US Class Current: 427/304
• CPC Class Codes: A61L 15/18 containing inorganic materials
• CPC Class Codes: A61L 15/46 Deodorants or malodour counteractants, e.g. to inhibit the formation of ammonia or bacteria
• CPC Class Codes: A61L 2300/102 Metals or metal compounds, e.g. salts such as bicarbonates, carbonates, oxides, zeolites, silicates
• CPC Class Codes: A61L 2300/104 Silver, e.g. silver sulfadiazine
• CPC Class Codes: A61L 2300/404 Biocides, antimicrobial agents, antiseptic agents
• CPC Class Codes: A61L 2300/45 Mixtures of two or more drugs, e.g. synergistic mixtures
• CPC Class Codes: A61L 2300/452 Lubricants
• CPC Class Codes: A61L 2300/606 Coatings
• CPC Class Codes: A61L 2300/608 having two or more layers
• CPC Class Codes: A61L 2300/61 containing two or more active agents in different layers
• CPC Class Codes: A61L 2300/802 Additives, excipients, e.g. cyclodextrins, fatty acids, surfactants
• CPC Class Codes: A61L 29/106 Inorganic materials other than carbon
• CPC Class Codes: A61L 29/16 Biologically active materials, e.g. therapeutic substances A61L29/048 takes precedence
• CPC Class Codes: A61L 31/088 Other specific inorganic materials not covered by A61L31/084 or A61L31/086
• CPC Class Codes: A61L 31/16 Biologically active materials, e.g. therapeutic substances A61L31/047 takes precedence
• 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: Y10S 604/905 Aseptic connectors or couplings, e.g. frangible, piercable
• CPC Class Codes: Y10T 428/12556 Organic component
• CPC Class Codes: Y10T 428/12562 Elastomer
• CPC Class Codes: Y10T 428/12569 : Synthetic resin
• CPC Class Codes: Y10T 428/12875 : Platinum group metal-base component
• CPC Class Codes: Y10T 428/12889 : Au-base component
• CPC Class Codes: Y10T 428/12896 : Ag-base component
• CPC Class Codes: Y10T 428/31692 : Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31707 : Next to natural rubber

Abstract

Metallic silver is deposited upon the surface of a nonconducting substrate using a multi-step wet deposition process. The surface is cleaned, and then activated in an aqueous solution containing stannous tin. The silver is deposited as a colloidal material from an aqueous solution of a silver-containing salt, a reduction agent that reduces the salt to form the metallic silver, and a deposition control agent that prevents the silver from nucleating throughout the solution. After the substrate is coated, the coating is stabilized in an aqueous solution of a salt of a metal from the platinum group or gold, dissolved in dilute hydrochloric acid. The process is particularly effective for depositing uniform films of 2 to 2000 Angstroms thickness, which strongly adhere to the substrate.

Claims

1. A method to prepare an article that resists bacterial growth, which article comprises a nonconductive substrate having coated on at least a portion of the surface area thereof an adhesive, thin, antimicrobial coating comprising a layer of silver which method comprises:

a) activating said portion of the surface area by treating said portion with stannous ion;

followed by

b) chemically depositing said silver layer by treating said activated surface with an aqueous solution of at least one salt of silver in the presence of a deposition control agent and in the absence of an electric current, said depositing being conducted for only sufficient time to result in a coating of 2-2,000 Å

in thickness;

followed by

c) rinsing said coating in demineralized water and drying said coating.

2. The method of claim 1 wherein said depositing is conducted in the absence of a reducing agent other than the activated portion of the surface area.

3. The method of claim 1 wherein said nonconductive substrate is latex, polystyrene, polyester, polyvinyl chloride, polyurethane, ABS polymers, polycarbonate, polyamide, polytetrafluoroethylene, polyimide, or synthetic rubber.

4. The method of claim 1 wherein said coating further contains a layer of one or more platinum group metal or gold or both and wherein said method further comprises, following step b) and before step c) treating said portion with a solution of a salt of said platinum group metal or gold or both in the absence of an electric current said treating being conducted for only sufficient time to result in said thin coating.

5. The method of claim 1 wherein said deposition control agent is sodium citrate, sodium acetate, sodium hydroxide, potassium hydroxide, ammonium or a combination of two or more of the foregoing.

6. The method of claim 1 which further comprises further coating said coated portion with a hydrogel layer.

7. The method of claim 4 which further comprises further coating said coated portion with a hydrogel layer.