CARBON MEMBRANE LAMINATED BODY AND METHOD FOR MANUFACTURING THE SAME

• US 20090242478A1
• Filed: 05/26/2009
• Published: 10/01/2009
• Est. Priority Date: 11/29/2006
• Status: Active Grant

• Current Assignee: NGK Insulators Limited
• Original Assignee: NGK Insulators Limited
• Inventors: Yabuki, Miyuki, Ichikawa, Akimasa
• Granted Patent: US 7,891,499 B2
• Time in Patent Office: Days
• US Class Current: 210/500.330
• CPC Class Codes: B01D 2325/04 Characteristic thickness
• CPC Class Codes: B01D 53/228 characterised by specific membranes
• CPC Class Codes: B01D 63/066 with a porous block having membrane coated passages
• CPC Class Codes: B01D 67/0067 by carbonisation or pyrolysis
• CPC Class Codes: B01D 69/12 Composite membranes; Ultra-thin membranes
• CPC Class Codes: B01D 69/1213 Laminated layers
• CPC Class Codes: B01D 69/125 In situ manufacturing by polymerisation, polycondensation, cross-linking or chemical reaction
• CPC Class Codes: B01D 71/021 Carbon

Abstract

A carbon membrane laminated body includes: a porous substrate, a first porous carbon membrane as a carbon membrane underlayer disposed on a surface of the porous substrate, and a second porous carbon membrane as a carbon membrane separation layer disposed on a surface of the carbon membrane underlayer, having a smaller film thickness, and a smaller average pore diameter, compared with those of the carbon membrane underlayer. It is preferable to form the carbon membrane underlayer and the carbon membrane separation layer by carbonizing a carbon membrane underlayer precursor disposed on a surface of the porous substrate and the carbon membrane separation layer precursor disposed on a surface of the carbon membrane underlayer precursor at 400 to 1000° C. in a non-oxidation atmosphere. The carbon membrane laminated body is a separation membrane excellent in both separation performance and flux when it is used as a separation membrane of a mixture.

Claims

1. A carbon membrane laminated body comprising:

a porous substrate,

a first porous carbon membrane as a carbon membrane underlayer disposed on a surface of the porous substrate, and

a second porous carbon membrane as a carbon membrane separation layer disposed on a surface of the carbon membrane underlayer, having a smaller film thickness and a smaller average pore diameter than those of the carbon membrane underlayer.

2. A carbon membrane laminated body according to claim 1, wherein the carbon membrane underlayer and the carbon membrane separation layer are formed by carbonizing a carbon membrane underlayer precursor as an underlayer precursor disposed on a surface of the porous substrate and a carbon membrane separation layer precursor as a separation layer precursor disposed on a surface of the underlayer precursor at 400 to 1000°

C. in a non-oxidation atmosphere.

3. A carbon membrane laminated body according to claim 2, wherein the underlayer precursor is a layer containing a polyimide resin as a main component.

4. A carbon membrane laminated body according to claim 2, wherein the separation layer precursor is a layer containing lignin as a main component.

5. A carbon membrane laminated body according claim 1, wherein the carbon membrane underlayer has a thickness of 0.05 to 5.0 μ

m, and the carbon membrane separation layer has a thickness of 0.001 to 1.0 μ

m.

6. A carbon membrane laminated body according to claim 1, wherein the carbon membrane underlayer has an average pore diameter of 0.2 to 100 nm, and the carbon membrane separation layer has an average pore diameter of 0.1 to 5.0 nm.

7. A carbon membrane laminated body according to claim 6, wherein the carbon membrane underlayer has an average pore diameter of 0.2 to 10 nm, and the carbon membrane separation layer has an average pore diameter of 0.1 to 1.0 nm.

8. A method for manufacturing a carbon membrane laminated body comprising the steps of:

disposing a first carbon membrane precursor as an underlayer precursor on a porous substrate to form an underlayer precursor-disposed body,

disposing a second carbon membrane precursor as a separation membrane precursor which is thinner than the underlayer precursor on a surface of the underlayer precursor to form a carbon membrane precursor laminated body, and

subjecting the carbon membrane precursor laminated body to a thermal treatment for carbonization of the underlayer precursor and the separation layer precursor to form respectively a carbon membrane underlayer disposed on a surface of the porous substrate and a carbon membrane separation layer disposed on a surface of the carbon membrane underlayer;

the carbon membrane separation layer having a smaller average pore diameter and a smaller film thickness than those of the carbon membrane underlayer.

9. A method for manufacturing a carbon membrane laminated body according to claim 8, wherein the thermal treatment is performed at 400 to 1000°

C. in a non-oxidation atmosphere.

10. A method for manufacturing a carbon membrane laminated body according to claim 8, wherein the underlayer precursor is a layer containing a polyimide resin as a main component.

11. A method for manufacturing a carbon membrane laminated body according to claim 8, wherein the separation layer precursor is a layer containing lignin as a main component.

12. A method for manufacturing a carbon membrane laminated body according to claim 8, wherein the carbon membrane underlayer has a thickness of 0.05 to 5.0 μ

m, and the carbon membrane separation layer has a thickness of 0.001 to 1.0 μ

m.

13. A method for manufacturing a carbon membrane laminated body according to claim 8, wherein the carbon membrane underlayer has an average pore diameter of 0.2 to 100 nm, and the carbon membrane separation layer has an average pore diameter of 0.1 to 5.0 nm.

14. A carbon membrane laminated body according to claim 13, wherein the carbon membrane underlayer has an average pore diameter of 0.2 to 10 nm, and the carbon membrane separation layer has an average pore diameter of 0.1 to 1.0 nm.