Linear-Hyperbranched Polymers as Performance Additives for Solid Electrolytic Capacitors

• US 20140160632A1
• Filed: 12/06/2013
• Published: 06/12/2014
• Est. Priority Date: 12/07/2012
• Status: Active Grant

• Current Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Original Assignee: Kemet Electronics Corporation (Yageo Corporation)
• Inventors: Chacko, Antony P., Shi, Yaru, Lessner, Philip M., Sivasankarapillai, Gopakumar
• Granted Patent: US 9,378,898 B2
• Time in Patent Office: Days
• US Class Current: 361/532
• CPC Class Codes: C09D 177/12 Polyester-amides
• CPC Class Codes: C09D 5/24 Electrically-conducting paints conductive materials H01B1/00
• CPC Class Codes: H01B 1/124 Intrinsically conductive polymers
• CPC Class Codes: H01G 9/0029 Processes of manufacture
• CPC Class Codes: H01G 9/028 Organic semiconducting electrolytes, e.g. TCNQ
• CPC Class Codes: H01G 9/0425 specially adapted for cathode
• CPC Class Codes: H01G 9/15 Solid electrolytic capacitors H01G11/00 takes precedence

Abstract

Provided herein is an improved capacitor and a method for forming an improved capacitor. The method includes providing an anode and forming a dielectric on the anode. A linear-hyperbranched polymer is formed and a conductive polymer dispersion is prepared comprising at least one conducting polymer, one polyanion and the linear-hyperbranched polymer. A layer of the conductive polymer dispersion if formed wherein said dielectric is between the anode and the layer.

Claims

1. A method for forming a capacitor comprising:

providing an anode;

forming a dielectric on said anode;

preparing a linear-hyperbranched polymer;

preparing a conductive polymer dispersion comprising at least one conducting polymer, one polyanion and said linear-hyperbranched polymer; and

forming a layer of said conductive polymer dispersion wherein said dielectric is between said anode and said layer.

2. The method for forming a capacitor of claim 1 wherein said anode comprises a valve metal or a conductive compound of said valve metal.

3. The method for forming a capacitor of claim 1 wherein said cathode comprises a conductive polymer or manganese dioxide.

4. The method forming a capacitor of claim 3 wherein said conductive polymer is selected from the group consisting of polypyrrole, polyaniline, polythiophene and substituted derivatives thereof.

5. The method for forming a capacitor of claim 1 wherein said dielectric is an oxide of said anode.

6. The method for forming a capacitor of claim 1 wherein said linear-hyperbranched polymer comprises a linear portion.

7. The method for forming a capacitor of claim 6 wherein said linear portion comprises at least two reactive groups.

8. The method for forming a capacitor of claim 7 wherein said reactive groups are selected from the group consisting of hydroxyl, amino and epoxy.

9. The method for forming a capacitor of claim 6 wherein said linear portion comprises at least one pendant group selected from polyimide-ester-amide, polyesteramide and polyesteramine.

10. The method for forming a capacitor of claim 6 wherein said linear portion comprises:

11. The method for forming a capacitor of claim 10 wherein said R₂₁ and R₂₅ are selected from the atoms necessary to form hydroxyl, amine or epoxy.

12. The method for forming a capacitor of claim 1 wherein said preparing of said linear-hyperbranched polymer comprises reacting a diol, an anhydride and an acrylate to form a linear portion.

13. The method for forming a capacitor of claim 12 wherein said diol is OH—

R₁—

OH wherein R₁ is a linear polymer with reactive groups.

14. The method for forming a capacitor of claim 12 wherein said anhydride is defined by:

15. The method for forming a capacitor of claim 14 wherein said ring is an aromatic ring.

16. The method for forming a capacitor of claim 12 wherein said acrylate is defined by:

17. The method for forming a capacitor of claim 16 wherein said acrylate is defined by:

18. The method for forming a capacitor of claim 16 wherein said acrylate is selected from the group consisting of 2-hydroxyethyl methacrylate, 2-hydroxyethyl acrylate (HEA), 2,2-bis(hydroxymethyl)propyl acrylate;

19. The method for forming a capacitor of claim 12 wherein said preparing of said linear-hyperbranched polymer comprises reacting said linear portion with a hydroxyl amine.

20. The method for forming a capacitor of claim 19 wherein said hydroxyl amine is defined by

21. The method for forming a capacitor of claim 20 wherein said hydroxyl amine is selected from:

22. The method for forming a capacitor of claim 1 wherein said linear-hyperbranched polymer comprises at least Generation 1 branching.

23. The method for forming a capacitor of claim 22 wherein said linear-hyperbranched polymer comprises at least Generation 2 branching.

24. The method for forming a capacitor of claim 22 wherein said linear-hyperbranched polymer has an acid number of at least 100 to no more than 1000.

25. The method for forming a capacitor of claim 24 wherein said linear-hyperbranched polymer has an acid number of no more than 500.

26. The method for forming a capacitor of claim 24 wherein said linear-hyperbranched polymer has an acid number of no more than 200.

27. The method for forming a capacitor of claim 1 wherein said binder has no more than 10 wt % sulfonate.

28. The method for forming a capacitor of claim 27 wherein said binder has no more than 0.1 wt % sulfonate.

29. The method for forming a capacitor of claim 1 wherein binder has no more than 10 wt % primary or secondary amines.

30. The method for forming a capacitor of claim 29 wherein binder has no more than 0.1 wt % primary or secondary amines.

31. The method for forming a capacitor of claim 1 further comprising cross-linking said cathode.

32. The method for forming a capacitor of claim 31 wherein cross-linking includes reacting reactive groups of said cathode with a crosslinker.

33. The method for forming a capacitor of claim 32 wherein said crosslinker is selected from a silane and a ethylene glycol diglycidyl ether.

34. The method for forming a capacitor of claim 33 wherein said crosslinker is selected from the group consisting of:

35. A capacitor comprising:

an anode;

a cathode wherein said cathode comprises a linear-hyperbranched polymer; and

a dielectric between said anode and said cathode.

36-64. -64. (canceled)

65. A capacitor comprising:

an anode;

a dielectric coated on the anode; and

a cathode comprising a reaction product of a hydroxyl amine with a reaction product of a diol an anhydride and an acrylate.

66-94. -94. (canceled)

95. A process of manufacturing a capacitor comprising:

providing an anode;

forming a dielectric on said anode;

forming a linear-hyperbranched polymer by reacting a diol a anhydride and an acrylate to form a linear portion and then reacting said linear portion with a hydroxyl amine;

forming a dispersion comprising said linear-hyperbranched polymer and a conductor; and

forming a cathode of said dispersion with said dielectric between said cathode and said anode.

96-124. -124. (canceled)

125. A dispersion for forming a conductive coating on a surface comprising a conductive polymer and a linear-hyperbranched polymer.

126-156. -156. (canceled)