High Thermal Conductivity Mica Paper Tape

• US 20080050580A1
• Filed: 09/25/2007
• Published: 02/28/2008
• Est. Priority Date: 06/15/2004
• Status: Abandoned Application

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: Smith, James, Wood, John, Lutz, Andreas, Stevens, Gary
• Application Number:
  US11/860,635
• Publication Number:
  US 20080050580A1
• Time in Patent Office: Days
• US Class Current: 428/327
• CPC Class Codes: B32B 2255/04 on a particulate layer
• CPC Class Codes: B32B 2255/24 Organic non-macromolecular coating
• CPC Class Codes: B32B 2260/021 Fibrous or filamentary layer layers of natural mineral fibres or particles being impregnated in a plastic substance B32B19/02
• CPC Class Codes: B32B 2260/025 Particulate layer layers of natural mineral fibres or particles being impregnated in a plastic substance B32B19/02
• CPC Class Codes: B32B 2260/046 Synthetic resin
• CPC Class Codes: B32B 2264/102 Oxide or hydroxide
• CPC Class Codes: B32B 2264/104 Oxysalt, e.g. carbonate, sulfate, phosphate or nitrate particles
• CPC Class Codes: B32B 2264/108 Carbon, e.g. graphite particles
• CPC Class Codes: B32B 2307/206 Insulating
• CPC Class Codes: B32B 2307/302 Conductive
• CPC Class Codes: B32B 2405/00 Adhesive articles, e.g. adhesive tapes labels B32B2519/00
• CPC Class Codes: B32B 2457/00 Electrical equipment
• CPC Class Codes: B32B 2581/00 Seals; Sealing equipment; Gaskets
• CPC Class Codes: B32B 2605/00 Vehicles
• CPC Class Codes: B32B 27/20 using fillers, pigments, thixotroping agents
• CPC Class Codes: B32B 29/02 next to a fibrous or filamentary layer
• CPC Class Codes: B32B 5/16 characterised by features of a layer formed of particles, e.g. chips, powder or granules layer formed of natural mineral particles B32B19/00; layer being formed of wood fibres, chips or particles B32B21/02
• CPC Class Codes: B32B 5/24 one layer being a fibrous or filamentary layer
• CPC Class Codes: B32B 5/30 one layer being formed of particles, e.g. chips, granules, powder
• CPC Class Codes: H01B 19/02 Drying; Impregnating
• CPC Class Codes: H01B 3/004 : with conductive additives or conductive layers
• CPC Class Codes: H01B 3/04 : mica
• CPC Class Codes: Y10T 428/25 : Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/254 : Polymeric or resinous material

Abstract

The impregnation of a composite tape (56) having a porous matrix with HTC particles provides for permeating a fabric substrate layer (51) of the composite tape with HTC particles and impregnating an impregnating resin into the composite tape (51). The HTC particles in the fabric (51) layer are comprised of a meso-micro mixture, which is between 1:4 to 4:1 meso sized particles to micro sized particles. Other smaller particles may also be included at lesser concentrations. The impregnating resin itself may also contain HTC particles.

Claims

1. A method for impregnating a composite tape with HTC particles for enhancing a thermal conductivity of said composite tape comprising:

permeating a fabric layer of said composite tape with HTC particles, wherein said HTC particles comprise a meso-micro mixture;

impregnating an impregnating resin into said composite tape through said fabric layer;

wherein at least 1% of said HTC particles permeated into said fabric layer are carried out of said fabric layer and into a mica layer bound to said fabric layer by said impregnating resin;

wherein said meso-micro mixture comprises meso sized HTC particles and micro sized HTC particles, and wherein the ratio of meso to micro is between 1;

4 and 4;

1 by weight;

whereby said HTC particles carried out of said fabric layer and into said mica layer provide a thermal conductivity effective for allowing reducing a thickness of said composite tape while maintaining a voltage endurance of said composite tape.

2. The method of claim 1, wherein the ratio of meso to micro is approximately 1:

1.

3. The method of claim 1, wherein said meso-micro mixture further comprise between 1-10% by weight nano sized HTC particles.

4. The method of claim 3, wherein said nano sized HTC particles are comprised of at least one of Al2O3, AlN, MgO, ZnO, BeO, BN, Si3N4, SiC and SiO2 with mixed stoichiometric and non-stoichiometric combinations.

5. The method of claim 1, wherein said meso-micro mixture is composed essentially of hexagonal boron nitride.

6. The method of claim 1, wherein said mica layer has HTC particles therein prior to the impregnation of the impregnating resin.

7. The method of claim 1, wherein the permeating of said fabric layer is performed after said fabric layer is bound to said mica layer.

8. The method of claim 7, wherein said fabric layer has a resinous backcoating on a side opposite to the side which said mica layer is bound, whereby said resinous backcoating keeps said HTC particles within said fabric layer.

9. The method of claim 1, wherein said impregnating resin contains HTC particles.

10. The method of claim 1, wherein an amount of HTC particles accumulate at the fabric layer/mica layer interface, whereby a region of densely packed HTC particles is created at the interface.

11. The method of claim 1, wherein said HTC particles are dry when they are permeated into said fabric layer.

12. The method of claim 1, wherein said HTC particles are mixed with at least one of resin and solvent when they are permeated into said fabric layer.

13. A method for impregnating a composite tape with HTC particles for enhancing a thermal conductivity of said composite tape comprising:

dry packing a fabric layer of said composite tape with HTC particles, wherein said HTC particles comprise a meso-micro mixture and at least 1-10% nano particles by weight;

sealing exposed surfaces of said fabric layer with a resin layer; and

impregnating said composite tape with an impregnating resin;

wherein said resin layer is soluble in said impregnating resin;

wherein said impregnating resin flows from said fabric layer into a mica layer bound to said fabric layer;

wherein at least 5% of said HTC particles in said fabric layer are carried by said impregnating resin into said mica layer, and where said nano particles tend to be carried furthest into said mica layer;

wherein said meso-micro mixture comprises meso sized HTC particles and micro sized HTC particles, and wherein the ratio of meso to micro is between 1;

4 and 4;

1 by weight;

whereby said HTC particles carried out of said fabric layer and into said mica layer provide a thermal conductivity effective for allowing reducing a thickness of said composite tape while maintaining a voltage endurance of said composite tape.

14. The method of claim 13, wherein said HTC particles have been surface functionalized.

15. The method of claim 14, wherein said smaller particles have been surface functionalized to limit interaction with other smaller particles.

16. The method of claim 13, wherein said HTC particles comprise 0.1-65% by volume of composite tape.

17. The method of claim 16, wherein said HTC particles comprise 1-25% by volume of composite tape.

18. The method of claim 13, wherein said fabric layer is glass.

19. The method of claim 13, wherein HTC materials are distributed and structurally organized by at least one of fluid flow fields, electric fields and magnetic fields.

20. A composite tape with HTC particles having enhanced thermal conductivity comprising:

a fabric layer of said composite tape permeated with HTC particles, wherein said HTC particles comprise a meso-micro mixture;

an resin impregnated into said composite tape;

wherein said meso-micro mixture comprises meso sized HTC particles and micro sized HTC particles, and wherein the ratio of meso to micro is between 1;

4 and 4;

1 by weight;

whereby said meso-micro mixture provides a thermal conductivity effective for allowing reducing a thickness of said composite tape while maintaining a voltage endurance of said composite tape.

21. The composite tape of claim 20, wherein the ratio of meso to micro is approximately 1:

1.

22. The composite tape of claim 20, wherein said meso-micro mixture further comprise between 1-10% by weight nano sized HTC particles.

23. The composite tape of claim 20, wherein said meso-micro mixture is composed essentially of hexagonal boron nitride.