Multi-layered platelet structure

• US 7,846,853 B2
• Filed: 01/23/2007
• Issued: 12/07/2010
• Est. Priority Date: 04/15/2005
• Status: Active Grant

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: Groeppel, Peter, Wood, John W., Stevens, Gary, Smith, James D. B.
• Primary Examiner(s): Piziali; Andrew T
• Application Number:
  US11/656,726
• Publication Number:
  US 20070141324A1
• Time in Patent Office: 1,414 Days
• Field of Search: 442/117, 442/417, 442/110, 442/180
• US Class Current: 442/117
• CPC Class Codes: H01B 3/025 Other inorganic material
• CPC Class Codes: H01B 3/04 mica
• CPC Class Codes: Y10T 428/24994 Fiber embedded in or on the surface of a polymeric matrix
• CPC Class Codes: Y10T 428/251 Mica
• CPC Class Codes: Y10T 428/2911 Mica flake
• CPC Class Codes: Y10T 442/2418 Coating or impregnation increases electrical conductivity or anti-static quality
• CPC Class Codes: Y10T 442/2475 Coating or impregnation is electrical insulation-providing, -improving, or -increasing, or conductivity-reducing
• CPC Class Codes: Y10T 442/2992 Coated or impregnated glass fiber fabric
• CPC Class Codes: Y10T 442/699 Including particulate material other than strand or fiber material

Abstract

An electrical insulation paper that is made of mica flakelets (22), having an average size range of 0.01 to 0.05 mm in their thinnest dimension, hexagonal boron nitride (26), which has an average size range of 10 to 1,000 nm in their longest dimension, and a resin matrix. The mica flakelets and the hexagonal boron nitride are mixed and formed into a paper (17), and the resin is added to the paper after formation, the ratio by weight of the hexagonal boron nitride to the mica flakelets is directly proportional to the average size of the hexagonal boron nitride compared to the average size of the mica flakelets, within an adjustment factor.

Claims

1. An electrical insulation system comprising:

mica flakelets, wherein said mica flakelets have an average size range of 0.01 to 0.05 mm in their thinnest dimension;

hexagonal boron nitride, wherein said hexagonal boron nitride has an average size range of 10 to 100 nm in their longest dimension; and

a resin matrix;

wherein said electrical insulation system comprises an electrical insulation composite comprising a mixture of said mica flakelets and said hexagonal boron nitride;

wherein a ratio by weight of said hexagonal boron nitride to said mica flakelets in said electrical insulation composite is directly proportional to the average size of said hexagonal boron nitride compared to the average size of said mica flakelets, within an adjustment factor of 0.5 to 2; and

wherein the ratio by weight of said hexagonal boron nitride to said mica flakelets in said electrical insulation composite is between 1;

100 and 1;

20 by weight.

2. The electrical insulation system of claim 1, further comprising high thermal conductivity fillers.

3. The electrical insulation system of claim 2, wherein said high thermal conductivity fillers comprises at least one of silica, alumina, magnesium oxide, silicon carbide, boron nitride, aluminum nitride, aluminum oxide, zinc oxide, titanium oxide, diamonds and dendrimers of approximately 1-1000 nm in size, and wherein said high thermal conductivity materials have aspect ratios of 10-50.

4. The electrical insulation system of claim 2, wherein said high thermal conductivity fillers are loaded into said resin matrix and comprise 25-40% by volume of said resin matrix.

5. The electrical insulation system of claim 1, wherein said mixture of mica flakelets and said hexagonal boron nitride are in the form of a paper.

6. An electrical insulation system comprising:

mica flakelets, wherein said mica flakelets have an average size range of 0.01 to 0.05 mm in their thinnest dimension;

hexagonal boron nitride, wherein said hexagonal boron nitride has an average size range of 10 to 1,000 nm in their longest dimension; and

a resin matrix;

wherein said electrical insulation system comprises a structurally stable electrical insulation paper consisting of said mica flakelets and said hexagonal boron nitride prior to addition of said resin matrix to said electrical insulation paper;

wherein the ratio by weight of said hexagonal boron nitride to said mica flakelets is directly proportional to the average size of said hexagonal boron nitride compared to the average size of said mica flakelets, within an adjustment factor of 0.5 to 2; and

wherein the ratio by weight of said hexagonal boron nitride to said mica flakelets is between 1;

100 and 1;

20.

7. The electrical insulation system of claim 6, further comprising high thermal conductivity fillers.

10. The electrical insulation system of claim 6, wherein the ratio of hexagonal boron nitride to mica flakelets is between 1:

100 and 1;

20 by weight.

8. An electrical insulation system comprising:

an electrical insulation composite comprising a mixture of platelet boron nitride and mica flakelets;

wherein said mica flakelets have an average size range of 0.01 to 0.05 mm in their thinnest dimension;

wherein said platelet boron nitride has an average size range of 10 to 10,000 nm in their longest dimension; and

wherein a ratio of said platelet boron nitride to said mica flakelets by weight is directly proportional to the average size ranges of said mica flakelets and said platelet boron nitride within a factor of 0.5 to 2;

wherein the ratio of platelet boron nitride to mica flakelets is between 1;

100 and 1;

20 by weight; and

wherein said electrical insulation composite is combined with a resin matrix to form said electrical insulation system.

9. The electrical insulation system of claim 8, wherein said platelet boron nitride is hexagonal boron nitride.