Cellulose material having impregnation and use of the cellulose material

Patent metadata

Field	Value
Publication number	US-9718934-B2
Application number	US-201414780457-A
Country	US
Kind code	B2
Filing date	Mar 11, 2014
Priority date	Mar 28, 2013
Publication date	Aug 1, 2017
Grant date	Aug 1, 2017

Abstract

Cellulose fibers are impregnated with polyethyleneimine so that the impregnation forms a type of network, which can reduce the specific resistance of the cellulose material owing to the electrical conductivity of the network. The cellulose material can thereby be advantageously adapted to use as electrical insulation of transformers, the cellulose material in this case being soaked in transformer oil. An adaptation of the specific resistance of the cellulose material to the specific resistance of the oil lead to improved dielectric strength of the transformer insulation. A method for impregnation of the cellulose material is described.

First claim

The invention claimed is:

1. A cellulose material, comprising:
multiple stacked plies, each ply comprising cellulose fibers with an impregnation of polyethyleneimine,
ionomers of the polyethyleneimine impregnation in each ply cross-linked in polymerized form to adjacent plies, and
the cellulose material having an electrical conductivity in a same order of magnitude as transformer oil.

2. The cellulose material as claimed in claim 1 , wherein the cellulose fibers are also impregnated with particles of titanium oxide.

3. The cellulose material as claimed in claim 2 , wherein the polyethyleneimine is appended to the particles of titanium oxide.

4. The cellulose material as claimed in claim 3 , wherein the cellulose material has a specific resistivity of 10 12 Ωm.

5. The cellulose material as claimed in claim 4 , wherein the cellulose material is flat and has a uniform concentration of the polyethyleneimine throughout.

6. The cellulose material as claimed in claim 3 , wherein the cellulose material is flat and has a uniform concentration of the polyethyleneimine throughout.

7. The cellulose material as claimed in claim 2 , wherein the cellulose material has a specific resistivity of 10 12 Ωm.

8. The cellulose material as claimed in claim 7 , wherein the cellulose material is flat and has a uniform concentration of the polyethyleneimine throughout.

9. The cellulose material as claimed in claim 2 , wherein the cellulose material is flat and has a uniform concentration of the polyethyleneimine throughout.

10. The cellulose material as claimed in claim 1 , wherein the cellulose material has a specific resistivity of 10 12 Ωm.

11. The cellulose material as claimed in claim 10 , wherein the cellulose material is flat and has a uniform concentration of the polyethyleneimine throughout.

12. The cellulose material as claimed in claim 1 , wherein the cellulose material is flat and has a uniform concentration of the polyethyleneimine throughout.

13. Insulation for a transformer containing transformer oil, comprising:
multiple stacked plies, each ply comprising cellulose fibers impregnated with polyethyleneimine,
ionomers of the polyethyleneimine impregnation in each ply cross-linked in polymerized form to adjacent plies, and
the insulation having an electrical conductivity in a same order of magnitude as the transformer oil in the transformer.

Assignees

• Siemens Ag

Inventors

• Heinrichsdorff Frank
• Lüthen Volkmar
• Winkler Gabriele

Classifications

• H01B3/185

  Substances or derivates of cellulose · CPC title

• D21H17/45 Primary

  Nitrogen-containing groups · CPC title

• C08J2379/04

  Polycondensates having nitrogen-containing heterocyclic rings in the main chain; Polyhydrazides; Polyamide acids or similar polyimide precursors · CPC title

• D21H17/56 Primary

  Polyamines; Polyimines; Polyester-imides · CPC title

• H01B3/303

  Macromolecular compounds obtained by reactions forming a linkage containing nitrogen with or without oxygen or carbon in the main chain of the macromolecule, not provided for in groups H01B3/38 or H01B3/302 · CPC title