# US 10,373,727 B2 · Prepreg mica tape and coil using same > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,373,727 B2 - Document ID: US10373727B2 - Status: Granted - Kind: B2 - Application number: 15/027,802 - Filed: 2014-10-09 - Published: 2016-08-25 - Granted: 2019-08-06 - Earliest claimed: 2013-10-09 - Assignees: Hitachi Chemical Company, Ltd. - Applicants: Hitachi Chemical Company, Ltd. - Inventors: Shihui Song; Takaya Yamamoto; Yoshitaka Takezawa - Web page: https://patentgrep.com/patent/US10373727B2 ## CPC - H01B 3/04: mica - C09J 7/20: characterised by their carriers - H01F 5/06: Insulation of windings - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) - C09J: ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES (preparation of glue or gelatine C09H) - H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES ## Abstract A prepreg mica tape includes: a backing material (3); a boron nitride-containing layer (1) that is provided on or above one surface of the backing material (3) and that includes a boron nitride particle (5) and a first resin (4); and a mica-containing layer (2) that is provided on or above the surface of the backing material (3) on which the boron nitride-containing layer (1) is provided and that includes mica (6) and a second resin (4). ## Claims ### Claim 1 A prepreg mica tape, comprising: a backing material; a boron nitride-containing layer that is provided on or above one surface of the backing material, and that comprises boron nitride and a first resin; and a mica-containing layer that is provided on or above the one surface of the backing material on which the boron nitride-containing layer is provided, and that comprises mica and a second resin, wherein a content of the boron nitride is from 10 to 50% by volume, with respect to a total amount of all solid contents except the backing material and the mica included in the prepreg mica tape, wherein the boron nitride-containing layer and the mica-containing layer are provided in this order on or above the one surface of the backing material, and wherein the backing material comprises a glass cloth, the first resin comprises an epoxy resin, the second resin is the first resin, and the first resin extends into the mica-containing layer, through the boron nitride-containing layer, and into the backing material. ### Claim 2 (depends on 1) The prepreg mica tape according to claim 1, wherein a percentage of mica pieces having a particle size of 2.8 mm or more, obtained by sieving the mica using a JIS standard sieve, is 50% by mass or more. ### Claim 3 (depends on 1) The prepreg mica tape according to claim 1, wherein the boron nitride has an average particle size of from 1 μm to 40 μm. ### Claim 4 (depends on 1) A coil, comprising an insulation layer that is a layered body of the prepreg mica tape according to claim 1. ### Claim 5 (depends on 1) The prepreg mica tape according to claim 1, formed by a process comprising: applying a boron nitride-containing resin varnish comprising the boron nitride and the first resin to the backing material, and bonding a mica paper to a surface of the backing material coated with the boron nitride-containing resin varnish so as to allow the mica paper to be impregnated with the first resin, the mica-containing layer comprising the mica paper and the first resin. ### Claim 6 (depends on 1) The prepreg mica tape according to claim 1, wherein the first resin extends through the backing material so as to cover opposite surfaces of the backing material, and the boron nitride is within portions of the first resin covering the opposite surfaces of the backing material. ### Claim 7 (depends on 1) The prepreg mica tape according to claim 1 having a thickness ranging from 200 to 400 μm. ### Claim 8 A prepreg mica tape, comprising: a backing material; a boron nitride-containing layer that is provided on or above one surface of the backing material, and that comprises boron nitride and a first resin; and a mica-containing layer that is provided on or above the one surface of the backing material on which the boron nitride-containing layer is provided, and that comprises mica and a second resin, wherein a content of the boron nitride is from 10 to 50% by volume, with respect to a total amount of all solid contents except the backing material and the mica included in the prepreg mica tape, and wherein at least a portion of the boron nitride-containing layer is disposed between the mica-containing layer and the backing material, the backing material comprises a glass cloth, the first resin and the second resin comprise an epoxy resin, and the epoxy resin extends into the mica-containing layer, through the boron nitride-containing layer, and into the backing material. ### Claim 9 (depends on 8) The prepreg mica tape according to claim 8, wherein the boron nitride-containing layer and the mica-containing layer are provided in this order on or above the one surface of the backing material. ### Claim 10 (depends on 8) The prepreg mica tape according to claim 8, wherein a percentage of mica pieces having a particle size of 2.8 mm or more, obtained by sieving the mica using a JIS standard sieve, is 50% by mass or more. ### Claim 11 (depends on 8) The prepreg mica tape according to claim 8, wherein the boron nitride has an average particle size of from 1 μm to 40 μm. ### Claim 12 (depends on 8) A coil, comprising an insulation layer that is a layered body of the prepreg mica tape according to claim 8. ### Claim 13 (depends on 8) The prepreg mica tape according to claim 8, formed by a process comprising: applying a boron nitride-containing resin varnish comprising the boron nitride and the first resin to the backing material, and bonding a mica paper to a surface of the backing material coated with the boron nitride-containing resin varnish so as to allow the mica paper to be impregnated with the first resin, the mica-containing layer comprising the mica paper and the first resin. ### Claim 14 (depends on 8) The prepreg mica tape according to claim 8, wherein the first resin extends through the backing material so as to cover opposite surfaces of the backing material, and the boron nitride is within portions of the first resin covering the opposite surfaces of the backing material. ### Claim 15 (depends on 8) The prepreg mica tape according to claim 8 having a thickness ranging from 200 to 400 μm.