Light transparent multilayer moisture barrier for electrochemical cell tester and cell employing same

• US 5,607,789 A
• Filed: 01/23/1995
• Issued: 03/04/1997
• Est. Priority Date: 01/23/1995
• Status: Expired due to Term

• Current Assignee: Gillette Company (The Procter & Gamble Company)
• Original Assignee: Duracell Incorporated (Berkshire Hathaway Incorporated)
• Inventors: Fenn, John B., Gibbard, H. Frank, Lagos, Bryan C., Treger, Jack, Wei, Guang
• Primary Examiner(s): NUZZOLILLO, MARIA
• Application Number:
  US08/376,274
• Time in Patent Office: 771 Days
• Field of Search: 429/90, 429/91, 429/92, 429/93, 324/435, 324/426, 324/433, 320/48
• US Class Current: 429/90
• CPC Class Codes: H01M 50/117 Inorganic material
• CPC Class Codes: H01M 50/121 Organic material
• CPC Class Codes: H01M 50/128 with two or more layers of only inorganic material
• CPC Class Codes: H01M 50/129 with two or more layers of only organic material
• CPC Class Codes: H01M 50/141 for protecting against humidity
• CPC Class Codes: H01M 50/24 adapted for protecting batteries from their environment, e.g. from corrosion thermal insulation H01M10/658
• CPC Class Codes: H01M 6/5044 Cells or batteries structurally combined with cell condition indicating means
• CPC Class Codes: H10K 50/8445 multilayered coatings having a repetitive structure, e.g. having multiple organic-inorganic bilayers
• CPC Class Codes: H10K 50/846 comprising getter material or desiccants

Abstract

A light transparent moisture barrier useful for preventing moisture from destroying the effectiveness of a moisture sensitive cell condition tester on an electrochemical cell comprises a plurality of very thin, alternating layers of an inorganic material and an organic material on a flexible, polymeric substrate. The layers are not laminated, but are formed on the substrate by a deposition or coating process and the thickness of any layer is less than 5 microns. The organic material is a hydrophobic polymer and the inorganic material is a metal oxide, nitride, a glass or silicon.

Claims

1. An electrochemical cell having a moisture sensitive cell condition tester and a light transparent moisture barrier, wherein said moisture barrier comprises a composite on a polymeric substrate, said composite comprising at least three alternating layers of a water insoluble inorganic material selected from the group consisting of at least one inorganic compound, silicon and mixture thereof and a water insoluble organic material wherein the thickness of said inorganic compound layers and said organic compound layers ranges between about 100 to 10,000 angstroms and between about 100 angstroms to 5 microns, respectively.

2. A cell according to claim 1 wherein the number of said alternating layers is at least four.

3. A cell according to claim 2 in which the outer layers of said moisture barrier are polymeric.

4. A cell according to claim 3 in which said moisture barrier has at least three layers of said inorganic material and at least three layers of said organic material.

5. A cell according to claim 1 wherein said moisture barrier has a moisture vapor transmission rate no greater than 15 micrograms of water per square inch of surface area over a twenty four hour period.

6. A cell according to claim 1 in which said organic material is hydrophobic.

7. A cell according to claim 6 in which said inorganic material comprises a glass.

8. A cell according to claim 7 wherein said glass comprises a tin-lead-phosphor-oxyfluoride.

9. A cell according to claim 8 wherein said moisture barrier has a moisture vapor transmission rate no greater than 15 micrograms of water per square inch of surface area over a twenty four hour period.

10. A cell according to claim 1 wherein said organic material comprises an acrylic polymer having hydrocarbon chains of at least six carbon atoms.

11. A cell according to claim 1 wherein said inorganic material is selected from the group consisting essentially of a nitride, an oxide, and mixture thereof.

12. A cell according to claim 11 wherein said organic material comprises a hydrophobic polymer.

13. A cell according to claim 12 wherein said moisture barrier has a moisture vapor transmission rate no greater than 15 micrograms of water per square inch of surface area over a twenty four hour period.

14. A cell according to claim 13 wherein said moisture barrier has at least three layers of said inorganic material and at least three layers of said organic material.

15. A cell according to claim 14 wherein said moisture barrier has a moisture vapor transmission rate no greater than 5 micrograms of water per square inch of surface area over a twenty four hour period.

16. A cell according to claim 15 wherein said moisture vapor transmission rate is no greater than 2 of water per square inch of surface area over a twenty four hour period.

17. A cell according to claim 1 wherein said moisture barrier has a moisture vapor transmission rate no greater than 2 micrograms of water per square inch of surface area over a twenty four hour period.

18. A cell according to claim 17 wherein said organic material comprises a hydrophobic polymer.