Claims
- 1. A composite coating for maintaining low moisture levels at the surface of solid substrates, which composite coating comprises:
- a substantially continuous first layer comprising first elastomeric polymer on said substrate, said first elastomeric polymer being substantially non-reactive with said substrate and being present in a thickness of at least about 0.1 millimeter;
- a substantially continuous second layer, on said first layer, comprising a mixture of desiccant and second elastomeric polymer having low permeability to water.
- 2. The composite coating according to claim 1, wherein said first elastomeric polymer is selected from the group consisting of: silicone elastomers, epoxy resins, vinyl plastisols and polyurethane.
- 3. The composite coating according to claim 1, wherein said first layer is present in a thickness between about 0.1 and about 10 millimeters.
- 4. The composite coating according to claim 1, wherein said first elastomeric polymer is substantially non-electronically conductive.
- 5. The composite coating according to claim 1, wherein said desiccant is selected from the group consisting of: silica gel, activated alumina, anhydrous calcium sulfate, magnesium perchlorate and hygroscopic salts wherein saturated solution of said hygroscopic salt corresponds to a relative humidity of less than about 50 percent.
- 6. The composite coating according to claim 5, wherein said hygroscopic salt is selected from the group consisting essentially of: calcium chloride, magnesium nitrate, sodium acetate, lithium chloride, and their salt hydrates.
- 7. The composite coating according to claim 5, wherein a saturated solution of said hygroscopic salt corresponds to a relative humidity between about 10 and about 30 percent.
- 8. The composite coating according to claim 1, wherein said second elastomeric polymer is selected from the group consisting essentially of polysiloxane, polyurethane rubbers, epoxy resins and vinyl plastisols.
- 9. The composite coating according to claim 1, wherein said second elastomeric polymer has a water permeability of less than 0.1 mg-mm/cm-day.
Parent Case Info
This is a division of application Ser. No. 07/133,820, filed Dec. 16,1987 now U.S. Pat. No. 4,939,014.
US Referenced Citations (20)
Divisions (1)
|
Number |
Date |
Country |
Parent |
133820 |
Dec 1987 |
|