HYDROPHILIC BODY AND METHOD OF MANUFACTURE

• US 20080011676A1
• Filed: 07/17/2006
• Published: 01/17/2008
• Est. Priority Date: 07/17/2006
• Status: Active Grant

• Current Assignee: Parker-Hannifin Corporation
• Original Assignee: General Electric Company
• Inventors: Olson, Karmin Lorraine
• Granted Patent: US 7,584,860 B2
• Time in Patent Office: Days
• US Class Current: 210/500.36
• CPC Class Codes: B01D 2323/02 Hydrophilization
• CPC Class Codes: B01D 2325/36 Hydrophilic membranes
• CPC Class Codes: B01D 67/0027 by stretching
• CPC Class Codes: B01D 67/0088 Physical treatment with compounds, e.g. swelling, coating or impregnation
• CPC Class Codes: B01D 71/36 Polytetrafluoroethene
• CPC Class Codes: B01D 71/54 Polyureas; Polyurethanes
• CPC Class Codes: B01D 71/70 Polymers having silicon in the main chain, with or without sulfur, nitrogen, oxygen or carbon only

Abstract

A hydrophilic body includes a porous membrane with hydrophobic properties. The porous membrane includes at least one of expanded polytetrafluoroethylene, woven polytetrafluoroethylene, and non woven polytetrafluoroethylene. A coating is formed on at least a portion of the porous membrane. The coating has hydrophilic properties and includes at least one of an organofunctional siloxane and a polyether urethane polymer.

Claims

1. A hydrophilic body consisting essentially of:

a porous membrane having hydrophobic properties and comprising at least one of expanded polytetrafluoroethylene, woven polytetrafluoroethylene, and non woven polytetrafluoroethylene; and

a coating formed on at least a portion of said porous membrane, said coating having hydrophilic properties and comprising at least one of an organofunctional siloxane and a polyether urethane polymer.

2. A hydrophilic body in accordance with claim 1 wherein said membrane is not laminated with a base material.

3. A hydrophilic body in accordance with claim 2 wherein said membrane comprises a weight of between about 0.1 and about 0.5 ounces per square yard.

4. A hydrophilic body in accordance with claim 2 wherein said membrane having a nominal pore size of between about 0.1 and about 1.0 microns.

5. A hydrophilic body in accordance with claim 2 wherein said membrane having a nominal pore size of between about 0.15 and about 0.5 microns.

6. A hydrophilic body in accordance with claim 1 wherein said coating comprises a coating composition having between about 1.0 and about 3.0 wt % solids based on the total weight of said coating composition.

7. A hydrophilic body in accordance with claim 1 wherein said hydrophilic body comprises an air permeability of between about 0.2 and about 0.6 CFM per square foot as measured in accordance with ASTM D737.

8. A hydrophilic body in accordance with claim 1 wherein said hydrophilic body remains hydrophilic after at least five wet then dry cycles.

9. A hydrophilic body in accordance with claim 1 wherein said hydrophilic body comprises a water permeability of between about 10 and 40 milliliters per minute per square centimeter at about 27 inches of mercury vacuum.

10. A hydrophilic body consisting essentially of:

a porous membrane having hydrophobic properties and comprising at least one of expanded polytetrafluoroethylene, woven polytetrafluoroethylene, and non woven polytetrafluoroethylene; and

a coating formed on at least a portion of said porous membrane, said coating having hydrophilic properties and comprising at least one of an organofunctional siloxane and a polyether urethane polymer

wherein said hydrophilic body does not include a base material.

11. A hydrophilic body in accordance with claim 10 wherein said membrane having a nominal pore size of between about 0.15 and about 0.5 microns.

12. A hydrophilic body in accordance with claim 11 wherein said coating comprises a coating composition having between about 1.0 and about 3.0 wt % solids based on the total weight of said coating composition.

13. A method for manufacturing a hydrophilic coating, said method comprising:

mixing a hydrophilic solid with a solvent, the hydrophilic solid comprising at least one of an organofunctional siloxane and a polyether urethane polymer;

mixing an activator having an ammonium containing salt with the mixture of the resin and the solvent.

14. A method in accordance with claim 13 wherein said actuator is ammonium hydroxide.

15. A method in accordance with claim 14 wherein said solvent comprises isopropyl alcohol,

16. A method of making a hydrophilic body, said method comprising:

mixing organofunctional siloxane and a solvent such that the organofunctional siloxane and the solvent form a coating solution;

applying the coating solution to a porous membrane.

17. A method in accordance with claim 16 wherein said method further comprises mixing an actuator in the coating solution.

18. A method in accordance with claim 16 further comprising curing the coating solution after the coating solution has been applied to the porous membrane at a temperature equal to or less than about 300°

F.

19. A method in accordance with claim 16 wherein said curing the coating solution comprises curing the coating solution at a temperature between about equal to or less than about 250°

F.