HYDROPHOBIC DEAERATION MEMBRANE

• US 20110087187A1
• Filed: 04/29/2009
• Published: 04/14/2011
• Est. Priority Date: 04/30/2008
• Status: Abandoned Application

• Current Assignee: Gambro Lundia AB (Baxter International Inc.)
• Original Assignee: Gambro Lundia AB (Baxter International Inc.)
• Inventors: Beck, Christof
• Application Number:
  US12/937,928
• Publication Number:
  US 20110087187A1
• Time in Patent Office: Days
• US Class Current: 604/500
• CPC Class Codes: A61M 1/3627 Degassing devices; Buffer reservoirs; Drip chambers; Blood filters
• CPC Class Codes: A61M 2205/7536 allowing gas passage, but preventing liquid passage, e.g. liquophobic, hydrophobic, water-repellent membranes
• CPC Class Codes: B01D 19/0031 by filtration
• CPC Class Codes: B01D 2323/26 Spraying processes
• CPC Class Codes: B01D 2325/04 Characteristic thickness
• CPC Class Codes: B01D 67/0088 Physical treatment with compounds, e.g. swelling, coating or impregnation
• CPC Class Codes: B01D 69/06 Flat membranes
• CPC Class Codes: B01D 69/12 Composite membranes; Ultra-thin membranes
• CPC Class Codes: B01D 71/027 Silicium oxide
• CPC Class Codes: B01D 71/36 Polytetrafluoroethene
• CPC Class Codes: B01D 71/70 Polymers having silicon in the main chain, with or without sulfur, nitrogen, oxygen or carbon only

Abstract

An optimized deaeration membrane has a biocompatible coating composition. Methods for preparing the membrane and the use of the membrane in medical devices for separating air from liquid that are administered to a living subject, e. g., blood processing devices used in dialysis and the like, are also described.

Claims

1. A deaeration membrane comprising porous polytetrafluoroethylene in sheet form coated with a defoaming agent comprising a polysiloxane and silicon dioxide particles, wherein the amount of coating is from 4 μ

g per mm² to 15 μ

g per mm² of the membrane and the silicon dioxide particles are present in an average concentration of from 22,000 particles per mm² to 44,000 particles per mm² of the coated deaeration membrane.

2. The membrane of claim 1, wherein the porous polytetrafluoroethylene sheet has a thickness of 0.15 mm to 0.30 mm.

3. The membrane of claim 1 wherein only one face of the polytetrafluoroethylene sheet is coated with the defoaming agent.

4. The membrane of claim 1 wherein the polysiloxane comprises polydimethylsiloxane.

16. The membrane of claim 2 wherein only one face of the polytetrafluoroethylene sheet is coated with the defoaming agent.

17. The membrane of claim 2 wherein the polysiloxane comprises polydimethylsiloxane.

18. The membrane of claim 3 wherein the polysiloxane comprises polydimethylsiloxane.

19. The membrane of claim 16 wherein the polysiloxane comprises polydimethylsiloxane.

5. A method for producing a deaeration membrane comprising porous polytetrafluoroethylene in sheet form coated with a defoaming agent comprising a polysiloxane and silicon dioxide particles, wherein the amount of coating is from 4 μ

g per mm² to 15 μ

g per mm² of the membrane and the silicon dioxide particles are present in an average concentration of from 22,000 particles per mm² to 44,000 particles per mm² of the coated deaeration membrane, the method comprising spray-coating a sheet of porous polytetrafluoroethylene with a solution comprising 0.1 wt. % to 20 wt. % of a defoaming agent comprising a polysiloxane and silicon dioxide particles.

6. The method of claim 5 further comprising cooling the solution to a temperature of from 0°

C. to 15°

C. before it is used for spray-coating the sheet of porous polytetrafluoroethylene.

7. A method for producing the a deaeration membrane comprising porous polytetrafluoroethylene in sheet form coated with a defoaming agent comprising a polysiloxane and silicon dioxide particles, wherein the amount of coating is from 4 μ

g per mm² to 15 μ

g per mm² of the membrane and the silicon dioxide particles are present in an average concentration of from 22,000 particles per mm² to 44,000 particles per mm² of the coated deaeration membrane, the method comprising roll coating a sheet of porous polytetrafluoroethylene with a solution comprising 20 wt. % to 70 wt. % of a defoaming agent comprising a polysiloxane and silicon dioxide particles.

8. The method of claim 7, wherein roll coating a sheet of porous polytetrafluoroethylene comprises roll coating the sheet of porous polytetrafluoroethylene with an anilox roll.

9. The method of claim 8 wherein roll coating a sheet of porous polytetrafluoroethylene with a solution comprising 20 wt. % to 70 wt. % of a defoaming agent comprising a polysiloxane and silicon dioxide particles comprises roll coating the sheet of porous polytetrafluoroethylene with a solution comprising 20 wt. % to 70 wt. % of a defoaming agent comprising polydimethylsiloxane and silicon dioxide particles.

20. The method of claim 7 wherein roll coating a sheet of porous polytetrafluoroethylene with a solution comprising 20 wt. % to 70 wt. % of a defoaming agent comprising a polysiloxane and silicon dioxide particles comprises roll coating the sheet of porous polytetrafluoroethylene with a solution comprising 20 wt. % to 70 wt. % of a defoaming agent comprising polydimethylsiloxane and silicon dioxide particles.

10. A method for removing entrained gases from a liquid comprising passing the liquid containing the entrained gases through a deaeration membrane comprising porous polytetrafluoroethylene in sheet form coated with a defoaming agent comprising a polysiloxane and silicon dioxide particles, wherein the amount of coating is from 4 μ

g per mm² to 15 μ

g per mm² of the membrane and the silicon dioxide particles are present in an average concentration of from 22,000 particles per mm² to 44,000 particles per mm² of the coated deaeration membrane.

11. The method according to claim 10 for removing entrained gases from a liquid containing protein.

12. The method according to claim 11 for removing entrained gases from blood.

13. The method according to claims 10 further comprising administering the liquid to a living subject.

14. The method according to claims 10 comprising placing the membrane is in direct contact with the liquid.

15. The method according to claims 10 further comprising placing the membrane in a deaeration device.