CN114214863A - Method for preparing high-thermal-conductivity mica paper based on spray freezing casting technology - Google Patents
Method for preparing high-thermal-conductivity mica paper based on spray freezing casting technology Download PDFInfo
- Publication number
- CN114214863A CN114214863A CN202111559836.1A CN202111559836A CN114214863A CN 114214863 A CN114214863 A CN 114214863A CN 202111559836 A CN202111559836 A CN 202111559836A CN 114214863 A CN114214863 A CN 114214863A
- Authority
- CN
- China
- Prior art keywords
- mica paper
- filler
- thermal conductivity
- conductivity
- paper
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21F—PAPER-MAKING MACHINES; METHODS OF PRODUCING PAPER THEREON
- D21F11/00—Processes for making continuous lengths of paper, or of cardboard, or of wet web for fibre board production, on paper-making machines
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
- D21H17/63—Inorganic compounds
- D21H17/67—Water-insoluble compounds, e.g. fillers, pigments
- D21H17/68—Water-insoluble compounds, e.g. fillers, pigments siliceous, e.g. clays
-
- D—TEXTILES; PAPER
- D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
- D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
- D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
- D21H21/14—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by function or properties in or on the paper
Abstract
The invention discloses an improved method for preparing high-thermal-conductivity mica paper, which comprises the following steps: the method comprises the following steps: mixing and stirring the heat-conducting filler, the adhesive and the solvent to obtain uniform filler slurry; step two: treating the uniformly mixed filler slurry by using a spray freeze dryer to obtain spherical porous filler particles; step three: pouring the porous filler and the mica powder into a fine pulp tank together, and fully stirring to prepare a slurry with a proper concentration; step four: and extracting the paper pulp into a paper machine, making and molding, drying, cooling, calendering, and finally coiling and slitting to obtain the high-thermal-conductivity oriented mica paper. The invention solves the problems of high filler content and poor air permeability, impregnability and electrical insulation of the traditional heat-conducting mica paper, and can greatly improve the heat-conducting property of the mica paper.
Description
Technical Field
The invention relates to the technical field of preparation of main insulation high-thermal conductivity mica paper for medium and large motors, and particularly relates to a preparation method for improving the thermal conductivity of mica paper.
Technical Field
Mica paper becomes one of key materials adopted by a stator winding with the rated voltage of more than 1kV by virtue of excellent high-temperature resistance and extremely strong partial discharge resistance. However, as the voltage class and stand-alone capacity of electric machines continue to increase, the market places higher demands on the heat resistance class of equipment insulation materials. The appearance of the mica paper with high thermal conductivity provides an effective solution to the problem. At present, researchers mainly improve the heat conductivity coefficient of mica paper by doping heat-conducting fillers such as aluminum oxide or boron nitride in the preparation process of the mica paper. Research shows that the composite material can only show excellent heat conducting capacity when the concentration of the filler exceeds 60 percent, because the filler particles cannot contact with each other to form a heat conducting channel when the filler is less, and the interface heat resistance between the filler and the paper base is added, the heat conducting effect of the mica paper is not obvious. When the amount of the filler is large, the phenomena of agglomeration, deposition and the like are easy to occur, so that the electrical property and the mechanical property of the insulating material are reduced, the aging speed of the mica paper is increased, and the application and the equipment performance of the mica paper in the field of power equipment are seriously influenced. Therefore, how to improve the stability of the motor insulation system by preparing the high-thermal-conductivity mica paper with high insulation level and good thermal conductivity is a difficult problem which needs to be solved urgently.
Disclosure of Invention
The invention provides a preparation method of a high-thermal-conductivity mica paper material for a motor, aiming at solving the defect that the existing motor main insulation mica paper has low insulation level and poor thermal conductivity. The spherical porous filler skeleton containing the multi-orientation heat conduction network and overlapped by the high molecular adhesive is prepared by adopting a spray freeze drying method, and the mica paper insulating material with high heat conductivity coefficient in the in-plane and out-of-plane directions can be prepared by doping the spherical porous filler skeleton into mica paper pulp under the condition of low filler filling content.
The invention is realized by the following technical scheme: a method for preparing high-thermal-conductivity oriented mica paper by a spray freezing casting technology comprises the following steps:
(1) according to the following steps of 1: weighing the binder and the high-thermal-conductivity powder as fillers according to the mass ratio of 1-2, wherein the mass ratio of the binder to the high-thermal-conductivity powder is 1: weighing deionized water and a dispersing agent in a mass ratio of 1-100 as a solvent to prepare a filler solution. Mixing and stirring the mixture by a dispersion machine, uniformly mixing the mixture, and removing bubbles in the solution by a vacuum defoaming machine.
(2) And (2) pouring the mixed solution obtained in the step (1) into a spray freeze dryer, and atomizing the solution into liquid drops by using an ejector. Under the action of low temperature, the liquid drops start to grow ice crystals from the surface to the center of the sphere, the binder and the inorganic powder are intensively extruded between the ice crystals, and the spherical porous filler particles with the multi-orientation heat-conducting network are prepared after freeze-drying.
(3) And (3) pouring the high-thermal-conductivity porous filler obtained in the step (2) and mica powder into a fine slurry pool, and fully stirring to prepare slurry with proper concentration.
(4) And (4) extracting the mica paper pulp fully and uniformly stirred in the step (3) to a paper machine for papermaking and molding.
(5) And squeezing, drying and cooling the manufactured mica paper to obtain the high-thermal-conductivity mica paper.
The preparation method of the mica paper with high thermal conductivity is characterized in that the solid content of the mixed filler solution in the step (1) is 15-30%.
The preparation method of the mica paper with high thermal conductivity is characterized in that the binder in the step (1) is one or more of povidone, polyethylene glycol, methyl cellulose, carboxymethyl cellulose, sodium carboxymethyl cellulose or polyvinyl alcohol.
The preparation method of the mica paper with high thermal conductivity is characterized in that the dispersant in the step (1) is one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, acetic acid, acetone or toluene.
The preparation method of the mica paper with high thermal conductivity is characterized in that the inorganic powder with high thermal conductivity in the step (1) is one or more of boron nitride, silicon nitride, aluminum nitride, magnesium oxide, silicon oxide or aluminum oxide.
The preparation method of the mica paper with high thermal conductivity is characterized in that the revolution of the dispersion machine in the step (1) is 500-1000 revolutions, and the vacuum defoaming time is 4 min.
The preparation method of the mica paper with high thermal conductivity is characterized in that the high thermal conductivity porous filler powder and the mica powder in the step (1) are mixed according to the weight ratio of 5-30: 70-95 by mass ratio.
Compared with the prior art, the invention has the beneficial effects that:
the heat conduction material prepared by the invention consists of a mica matrix and high-heat-conduction inorganic filler. Wherein, the filler solution is frozen and dried to form spherical porous heat-conducting filler particles with controllable particle size, good dispersibility and high solubility. Because the filler is oriented from the spherical surface to the spherical center, a framework with a multi-orientation heat conduction channel is formed, and high heat conductivity coefficients in the in-plane and the out-plane directions can be simultaneously realized under low filling content. In addition, the porosity of the filler can increase the air permeability of the mica paper to a certain extent, so that the resin can be completely impregnated in the VPI process. The mica paper with high thermal conductivity is used for motor stator insulation, and has higher thermal conductivity and breakdown field strength.
Detailed Description
The technical solutions of the present invention are further described below with reference to the specific embodiments, but the present invention is not limited thereto, and any modifications or equivalent substitutions made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention should be covered by the protection scope of the present invention.
The embodiment provides a method for preparing high-thermal-conductivity mica paper by a freeze casting method, which comprises the following specific implementation steps of:
(1) 50kg of polyvinyl alcohol and 100kg of a filler were added to a mixed solvent containing 50kg of acetone and 300 kg. Stirring the mixed solution by a dispersion machine at the speed of 1000 revolutions, uniformly mixing, and defoaming the solution by a vacuum defoaming machine.
(2) The mixed solution is poured into a spray freeze dryer, and the solution is atomized into liquid drops by using an ejector. Under the action of low temperature, the liquid drops start to grow ice crystals from the surface to the center of the sphere, the binder and the inorganic powder are intensively extruded between the ice crystals, and the spherical porous filler particles with the multi-orientation heat-conducting network are prepared after freeze-drying.
(3) Pouring the high-thermal-conductivity porous filler and 350kg of mica powder into a fine pulp pool containing 50000kg of water, and fully stirring to prepare mica slurry with the concentration of 1%.
(4) And extracting the mica paper pulp to a paper machine for papermaking and molding.
(5) And squeezing, drying and cooling the manufactured mica paper to obtain the high-thermal-conductivity mica paper.
In conclusion, compared with the existing products, the high-thermal-conductivity mica paper prepared by the invention has the advantages of controllable particle size, good dispersibility, high solubility and multi-orientation thermal-conductivity channels. The high-thermal-conductivity mica paper prepared by doping the mica paper pulp can realize higher in-plane and out-of-plane thermal conductivity coefficients at the same time. In addition, the mica paper has good air permeability, and has higher heat conductivity coefficient and breakdown field intensity after being soaked.
Claims (7)
1. The preparation method of the mica paper with high thermal conductivity is characterized by comprising the following steps:
(1) according to the following steps of 1: weighing the binder and the high-thermal-conductivity inorganic powder as a filler in a mass ratio of 1-2, wherein the weight ratio of the binder to the high-thermal-conductivity inorganic powder is 1: weighing deionized water and a dispersing agent in a mass ratio of 1-100 to serve as a solvent to prepare a filler solution, mixing and stirring the filler solution by using a dispersing machine, and removing bubbles in the solution by using a vacuum defoaming machine after uniformly mixing;
pouring the mixed solution obtained in the step (1) into a spray freeze dryer, atomizing the solution into liquid drops by using an ejector, starting to grow ice crystals from the surface to the center of a sphere by the liquid drops under the action of low temperature, intensively extruding a binder and inorganic powder between the ice crystals, and freeze-drying to prepare spherical porous filler particles of the multi-orientation heat-conducting network;
(2) pouring the high-thermal-conductivity porous filler obtained in the step (2) and mica powder into a fine slurry pool together for fully stirring to prepare slurry with proper concentration;
(3) extracting the mica paper pulp fully and uniformly stirred in the step (3) to a paper machine for papermaking and molding;
(4) and (4) squeezing, drying and cooling the manufactured mica paper manufactured in the step (4) to obtain the high-thermal-conductivity mica paper.
2. The method for preparing mica paper with high thermal conductivity according to claim 1, wherein the solid content of the mixed filler solution in the step (1) is 15-30%.
3. The method for preparing mica paper with high thermal conductivity according to claim 1, wherein the binder in step (1) is one or more of povidone, polyethylene glycol, methylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, or polyvinyl alcohol.
4. The method for preparing mica paper with high thermal conductivity according to claim 1, wherein the dispersant in step (1) is one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, acetic acid, acetone or toluene.
5. The method for preparing mica paper with high thermal conductivity according to claim 1, wherein the inorganic powder with high thermal conductivity in step (1) is one or more of boron nitride, silicon nitride, aluminum nitride, magnesium oxide, silicon oxide or aluminum oxide.
6. The method for preparing mica paper with high thermal conductivity according to claim 1, wherein the rotation number of the disperser in the step (1) is 500-1000 r, and the vacuum defoaming time is 4 min.
7. The preparation method of the mica paper with high thermal conductivity according to claim 1, wherein the ratio of the high thermal conductivity porous filler powder in the step (2) to the mica powder is 5-30: 70-95 by mass ratio.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111559836.1A CN114214863A (en) | 2021-12-20 | 2021-12-20 | Method for preparing high-thermal-conductivity mica paper based on spray freezing casting technology |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111559836.1A CN114214863A (en) | 2021-12-20 | 2021-12-20 | Method for preparing high-thermal-conductivity mica paper based on spray freezing casting technology |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN114214863A true CN114214863A (en) | 2022-03-22 |
Family
ID=80704162
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111559836.1A Pending CN114214863A (en) | 2021-12-20 | 2021-12-20 | Method for preparing high-thermal-conductivity mica paper based on spray freezing casting technology |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114214863A (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110040007A1 (en) * | 2009-08-17 | 2011-02-17 | Laird Technologies, Inc. | Highly thermally-conductive moldable thermoplastic composites and compositions |
| CN106996053A (en) * | 2017-03-17 | 2017-08-01 | 湖北平安电工材料有限公司 | A kind of high heat conduction mica paper manufacture method |
| WO2018038984A1 (en) * | 2016-08-25 | 2018-03-01 | 3M Innovative Properties Company | Thermally conductive electrical insulation material |
| CN112551494A (en) * | 2020-12-10 | 2021-03-26 | 中国科学院深圳先进技术研究院 | Size-controllable aerogel ball and preparation method and application thereof |
| CN112553947A (en) * | 2020-12-02 | 2021-03-26 | 通城县云水云母科技有限公司 | High-heat-conductivity and high-strength mica paper and production method thereof |
| CN113754454A (en) * | 2021-09-24 | 2021-12-07 | 中国矿业大学 | Preparation method and application of carbon fiber/silicon carbide directional porous framework |
-
2021
- 2021-12-20 CN CN202111559836.1A patent/CN114214863A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110040007A1 (en) * | 2009-08-17 | 2011-02-17 | Laird Technologies, Inc. | Highly thermally-conductive moldable thermoplastic composites and compositions |
| WO2018038984A1 (en) * | 2016-08-25 | 2018-03-01 | 3M Innovative Properties Company | Thermally conductive electrical insulation material |
| CN106996053A (en) * | 2017-03-17 | 2017-08-01 | 湖北平安电工材料有限公司 | A kind of high heat conduction mica paper manufacture method |
| CN112553947A (en) * | 2020-12-02 | 2021-03-26 | 通城县云水云母科技有限公司 | High-heat-conductivity and high-strength mica paper and production method thereof |
| CN112551494A (en) * | 2020-12-10 | 2021-03-26 | 中国科学院深圳先进技术研究院 | Size-controllable aerogel ball and preparation method and application thereof |
| CN113754454A (en) * | 2021-09-24 | 2021-12-07 | 中国矿业大学 | Preparation method and application of carbon fiber/silicon carbide directional porous framework |
Non-Patent Citations (2)
| Title |
|---|
| 朱洪法（主编）: "《催化剂手册》", 31 August 2008, 金盾出版社 * |
| 达道安（主编）: "《真空设计手册》", 31 July 2004, 国防工业出版社 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR20190082818A (en) | Manufacturing method of anode slurry for secondary battery | |
| KR20190082819A (en) | Anode slurry for secondary battery | |
| CN104701560B (en) | A kind of fuel battery proton exchange film and preparation method thereof | |
| CN112195016B (en) | Heat-conducting insulating carbon fiber silica gel gasket and preparation method thereof | |
| CN114854087A (en) | Polyimide composite material with double heat-conducting networks and preparation method thereof | |
| CN113480760A (en) | Preparation method of high-breakdown and high-dielectric FPE (Fabry-Perot) based composite material film | |
| CN115232444A (en) | High-thermal-conductivity spherical boron nitride composite epoxy resin and preparation method thereof | |
| CN114214863A (en) | Method for preparing high-thermal-conductivity mica paper based on spray freezing casting technology | |
| CN111533486A (en) | Graphene modified resin packaging material and preparation method thereof | |
| CN114539783B (en) | High-heat-conductivity high-insulation gasket and preparation method thereof | |
| CN109228549B (en) | Preparation method of high-thermal-conductivity nanocellulose-based electrical insulation film material | |
| CN114232388A (en) | Method for preparing high-thermal-conductivity mica paper based on freezing casting technology | |
| CN106328896B (en) | A kind of graphene network sulfur electrode material and preparation method | |
| KR20210003942A (en) | Battery incorporating silica fiber | |
| CN114496349B (en) | Ultra-long high-temperature-resistant mica tape and preparation method thereof | |
| CN114149685B (en) | High-frequency high-speed copper-clad plate containing nano inorganic mullite alumina hollow microbeads | |
| CN101338072A (en) | Organic/inorganic composite enhancement type anhydrous proton conducting film and method for preparing same | |
| CN114380958A (en) | High-thermal-conductivity epoxy VPI resin for high-voltage motor and preparation method and application thereof | |
| CN110628183B (en) | Epoxy glass fiber nanocomposite for high-voltage switch insulating pull rod and preparation method thereof | |
| CN114214864B (en) | Method for preparing high-thermal-conductivity mica paper based on ice template method | |
| CN116655996B (en) | Aramid nanofiber/nanocellulose composite aerogel and preparation method and application thereof | |
| CN114933735B (en) | Preparation method of polymer-based heat-insulating aerogel material | |
| CN114318931A (en) | Method for preparing high-thermal-conductivity mica paper based on electric field orientation | |
| CN109337167B (en) | High-thermal-conductivity flame-retardant polyethylene-based composite material and preparation method thereof | |
| CN114836007B (en) | High-heat-conductivity resin insulating material and preparation method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |