High temperature resistant insulation mica tape and preparation method thereof

Abstract

The application relates to the technical field of insulating materials, in particular to a high-temperature-resistant insulating mica tape and a preparation method thereof, which is formed by compounding and solidifying a mica paper layer, a reinforcing material layer and a high-temperature-resistant adhesive coated on the adhering surfaces of the two layers; the high-temperature-resistant adhesive comprises an organic silicon resin compound, a ternary high-temperature-resistant filler, a silane coupling agent, a curing agent and a diluent; the organic silicon resin compound is compounded by methylphenyl silicon resin and phenyl vinyl silicon resin; and the ternary high-temperature-resistant filler is a mixture of nano-aluminum oxide, nano-magnesium oxide and mica powder. The high-temperature-resistant insulating mica tape and the preparation method thereof effectively solve the technical problems of low temperature resistance, poor high-temperature aging performance and insufficient mechanical and insulating performance of traditional mica tapes, and the overall performance is comprehensively improved.

Description

Technical Field

[0001] This invention relates to the field of insulating materials technology, specifically to a high-temperature resistant insulating mica tape and its preparation method. Background Technology

[0002] Insulating mica tape, as a key insulating structural material, is widely used in the winding insulation protection of equipment such as motors, transformers, and reactors. It is often used in combination with various winding cables such as QY type polyimide enameled round copper wire, QZY type polyimide enameled flat copper wire, and JXN type motor winding lead wire to form the core insulation structure of the equipment winding. The temperature resistance, insulation performance, mechanical properties of mica tape and its compatibility with cables directly determine the operational stability and overall service life of the electrical equipment winding insulation system.

[0003] As modern industry demands increasingly smaller, higher-power, and higher-temperature-resistant electrical equipment, the temperature resistance and insulation performance of various high-end winding cables are also being upgraded. Traditional insulating mica tape is gradually becoming insufficient to meet practical application requirements. Existing mica tapes mostly use a single resin as an adhesive. The resin system lacks sufficient temperature resistance and cross-linking density, making it prone to aging and cracking under high-temperature conditions. This leads to a rapid decline in its own insulation performance and can also cause interlayer delamination problems with composite cables, damaging the overall insulation structure of the winding. The filler system is mostly a binary combination, with poor dispersion and compatibility, which cannot effectively synergistically improve the high-temperature resistance and mechanical properties of the mica tape, making it difficult to match the high-temperature working environment and long-term mechanical stress requirements faced by cable windings in high-power equipment.

[0004] Meanwhile, the traditional preparation process involves uneven dispersion of adhesives and a single curing process, which can easily lead to defects inside the mica tape. This not only reduces core properties such as breakdown strength and tensile strength, but also results in a low performance retention rate after high-temperature aging, making it difficult to adapt to the application scenarios of cable windings with temperature resistance ratings of H and above.

[0005] Furthermore, some mica tapes have poor compatibility with reinforcing materials and adhesives, resulting in weak interlayer bonding. When combined with cables, the insulation layer is prone to loosening and damage under the vibration and high-temperature alternating environment of long-term equipment operation. This further limits its application in high-temperature and harsh environments with high-grade winding cables. Therefore, developing an insulating mica tape with high temperature resistance, high insulation, high mechanical strength, and excellent high-temperature stability, which can be well adapted to various high-end winding cables, has become an urgent problem to be solved in the industry. Summary of the Invention

[0006] The primary objective of this invention is to provide a high-temperature resistant insulating mica tape and its preparation method.

[0007] A further objective of this invention is to provide a high-temperature resistant insulating mica tape, which is formed by composite curing of a mica paper layer, a reinforcing material layer, and a high-temperature resistant adhesive coated on the bonding surfaces of the two; the high-temperature resistant adhesive comprises an organosilicon resin compound, a ternary high-temperature resistant filler, a silane coupling agent, a curing agent, and a diluent, wherein the organosilicon resin compound is composed of methylphenyl silicone resin and phenyl vinyl silicone resin, and the ternary high-temperature resistant filler is a mixture of nano-alumina, nano-magnesium oxide, and mica powder.

[0008] Preferably, the mica paper layer is phlogopite paper; the reinforcing material layer is alkali-free glass fiber cloth or polyimide film.

[0009] Preferably, the silane coupling agent is KH550 or KH560; the curing agent is an organotin curing agent or an amine curing agent; and the diluent is xylene.

[0010] Preferably, by weight, the high-temperature resistant adhesive comprises 100 parts of methyl phenyl silicone resin and phenyl vinyl silicone resin, 5-15 parts of nano alumina, 20-30 parts of nano magnesium oxide, 35-65 parts of mica powder, 2-4.5 parts of silane coupling agent, 3-6.5 parts of curing agent, and 18 parts of diluent.

[0011] A method for preparing the high-temperature resistant insulating mica tape according to any one of claims 1 to 4, comprising the following steps: (1) Preparation of high temperature resistant adhesive: Mix methyl phenyl silicone resin and phenyl vinyl silicone resin, add diluent, stir until completely dissolved, add silane coupling agent and continue stirring, then add ternary high temperature resistant filler for high-speed dispersion, and finally add curing agent and stir to obtain high temperature resistant adhesive; (2) Composite molding: High-temperature resistant adhesive is coated on one side of the mica paper layer and the reinforcing material layer, and the composite is completed by hot pressing to obtain the composite blank; (3) Segmented baking and curing: The composite preform is baked at three different temperatures in sequence to complete the curing process and obtain the cured preform; (4) Slitting: The cured blank is slitted into strips to obtain the finished high-temperature resistant insulating mica tape.

[0012] Preferably, in step (1), the stirring speed of the diluent after mixing methylphenyl silicone resin and phenyl vinyl silicone resin is 400 rpm; the high-speed dispersion speed after adding ternary high-temperature resistant filler is 1500 rpm.

[0013] Preferably, in step (1), the stirring time after adding the silane coupling agent is 20 minutes; the high-speed dispersion time after adding the ternary high-temperature resistant filler is 45 minutes; and the stirring time after adding the curing agent is 30 minutes.

[0014] Preferably, in step (2), the amount of high-temperature resistant adhesive applied to one side is 5-12 grams per square meter; the temperature of the hot pressing treatment is 70-100 degrees Celsius, the pressure is 0.3-0.6 MPa, and the time is 15-25 seconds.

[0015] Preferably, in step (3), the temperature of the first stage of baking is 85-110 degrees Celsius and the holding time is 12-18 minutes; the temperature of the second stage of baking is 135-165 degrees Celsius and the holding time is 18-25 minutes; the temperature of the third stage of baking is 215-245 degrees Celsius and the holding time is 15-25 minutes.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. The high-temperature resistant insulating mica tape and its preparation method provided by the present invention effectively solve the technical problems of low temperature resistance, poor high-temperature aging performance, and insufficient mechanical and insulating properties of traditional mica tape, and the overall performance is comprehensively improved.

[0017] 2. This invention uses a compounded silicone resin as the main adhesive and a ternary high-temperature resistant filler system to achieve synergistic compatibility between the resin and the filler, which greatly improves the temperature resistance of the mica tape and can stably reach the H-level temperature resistance standard. It can still maintain excellent structural stability under high-temperature conditions.

[0018] 3. The scientific combination of filler and coupling agent in this invention optimizes the dispersibility of the system and significantly improves the breakdown strength, tensile strength and volume resistivity of mica tape, achieving a balance between insulation and mechanical properties.

[0019] 4. The segmented baking curing process design of this invention effectively avoids the internal defects caused by a single curing process, improves the interlayer bonding force, and enables the mica tape to maintain a high performance retention rate after high-temperature aging, and greatly enhances high-temperature stability.

[0020] 5. This invention can flexibly optimize the raw material ratio and process parameters according to actual application needs, adapt to different reinforcing materials, has a wide range of applications, and the preparation process is simple and controllable, making it easy to carry out large-scale industrial production. Compared with the existing technology, it has significant technical advantages and practical value, and can meet the application needs of high-temperature resistant insulation materials for high-end electrical equipment. Detailed Implementation

[0021] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0022] The mica paper layer is made of phlogopite paper with a thickness of 0.10 mm, and the reinforcing material layer is made of alkali-free glass fiber cloth with a thickness of 0.03 mm. The high-temperature resistant adhesive consists of the following components by weight: 70 parts methyl phenyl silicone resin, 30 parts phenyl vinyl silicone resin, 15 parts nano alumina, 20 parts nano magnesium oxide, 65 parts mica powder, 2 parts silane coupling agent KH550, 3 parts organotin curing agent, and 18 parts xylene.

[0023] The preparation process is as follows: Methylphenyl silicone resin and phenyl vinyl silicone resin are mixed, and xylene is added. The mixture is stirred at 400 rpm until completely dissolved. Silane coupling agent KH550 is added, and stirring continues for 20 minutes. Then, nano-alumina, nano-magnesium oxide, and mica powder are added, and the mixture is dispersed at 1500 rpm for 45 minutes. Finally, organotin curing agent is added, and the mixture is stirred for 30 minutes to obtain a high-temperature resistant adhesive. This adhesive is coated on one side of a mica paper layer and a reinforcing material layer, with a coating amount of 12 grams per square meter. The composite is then hot-pressed for 15 seconds at 100 degrees Celsius and 0.3 MPa to complete the lamination. The composite preform is then cured by baking at 110 degrees Celsius for 12 minutes, 165 degrees Celsius for 18 minutes, and 215 degrees Celsius for 25 minutes. The cured preform is then cut into 25 mm wide strips to obtain high-temperature resistant insulating mica tape. Example

[0024] This embodiment is based on the core system of Example 1, with optimization of the resin compounding ratio. The amount of methylphenyl silicone resin is 45 parts, and the amount of phenyl vinyl silicone resin is 55 parts. The specifications of the mica paper layer, the specifications of the reinforcing material layer, the types and amounts of high-temperature resistant fillers, coupling agents, curing agents, and diluents, as well as all process parameters for adhesive preparation, coating, lamination, segmented baking, and slitting are completely consistent with those of Example 1, resulting in a high-temperature resistant insulating mica tape. Example

[0025] This embodiment is based on the core system of Example 1, with optimization of the ternary filler ratio. The amount of nano-alumina is 5 parts, the amount of nano-magnesium oxide is 30 parts, and the amount of mica powder is 65 parts. The types and amounts of organosilicon resin compound, coupling agent, curing agent, and diluent, the specifications of the mica paper layer and the reinforcing material layer, and all preparation process parameters are completely consistent with those of Example 1, resulting in a high-temperature resistant insulating mica tape. Example

[0026] This embodiment is based on the core system of Example 1, with optimization of the total filler content. The total mass of the high-temperature resistant filler is 70 parts, including 15 parts of nano-alumina, 20 parts of nano-magnesium oxide, and 35 parts of mica powder. The types and amounts of the organosilicon resin compound, coupling agent, curing agent, and diluent, the specifications of the mica paper layer and the reinforcing material layer, and all preparation process parameters are completely consistent with those of Example 1, resulting in a high-temperature resistant insulating mica tape. Example

[0027] This embodiment is based on the core system of Example 1, with optimizations made to the compatibility of the reinforcing material. The reinforcing material layer is replaced with a polyimide film with a thickness of 0.07 mm. The specifications of the mica paper layer, the silicone resin compound, the high-temperature resistant filler, the coupling agent, the curing agent, the type and amount of diluent, and all preparation process parameters are completely consistent with those of Example 1, resulting in a high-temperature resistant insulating mica tape. Example

[0028] This embodiment is based on the core system of Embodiment 1, with optimizations to the segmented baking process. The first stage baking temperature is 85 degrees Celsius, and the holding time is 18 minutes; the second stage baking temperature is 135 degrees Celsius, and the holding time is 25 minutes; the third stage baking temperature is 245 degrees Celsius, and the holding time is 15 minutes. The specifications of the mica paper layer and the reinforcing material layer, the types and amounts of all raw materials, and the process parameters for adhesive preparation, coating, lamination, and slitting are all completely consistent with those of Embodiment 1, resulting in a high-temperature resistant insulating mica tape. Example

[0029] This embodiment is based on the core system of Embodiment 1, with synergistic optimization of the adhesive application amount and hot-pressing parameters. The single-sided adhesive application amount is 5 grams per square meter, the hot-pressing composite pressure is 0.6 MPa, the hot-pressing temperature is 70 degrees Celsius, and the hot-pressing time is 25 seconds. The specifications of the mica paper layer and the reinforcing material layer, the types and amounts of all raw materials, as well as the process parameters for adhesive preparation, segmented baking, and slitting are completely consistent with those of Embodiment 1, resulting in a high-temperature resistant insulating mica tape. Example

[0030] This embodiment is based on the core system of Example 1, with synergistic optimization of the coupling agent and curing agent. The coupling agent is replaced with silane coupling agent KH560, with a dosage of 4.5 parts; the curing agent is replaced with an amine curing agent, with a dosage of 6.5 parts. The specifications of the mica paper layer and the reinforcing material layer, the types and dosages of other raw materials, and all preparation process parameters are completely consistent with those of Example 1, resulting in a high-temperature resistant insulating mica tape.

[0031] Comparative Example 1: Comparative samples were prepared using a single resin system based on existing technology: Based on the raw material specifications and preparation process of Example 1, the high-temperature resistant adhesive used only 100 parts of methylphenyl silicone resin, without adding phenyl vinyl silicone resin. The types and amounts of other raw materials, the specifications of the mica paper layer and the reinforcing material layer, the coating parameters, the composite conditions, the segmented baking regime, and the slitting specifications were all exactly the same as in Example 1, and comparative samples were obtained.

[0032] Comparative Example 2: Comparative samples were prepared using a binary filler system based on existing technology: Based on the raw material specifications and preparation process of Example 1, only 50 parts of nano-alumina and 50 parts of mica powder were used as the high-temperature resistant filler, without the addition of nano-magnesium oxide. The types and amounts of other raw materials, the specifications of the mica paper layer and the reinforcing material layer, the adhesive parameters, the composite conditions, the segmented baking regime, and the slitting specifications were all exactly the same as in Example 1, and comparative samples were obtained.

[0033] Comparative Example 3: Comparative samples were prepared using existing conventional adhesive systems: Based on the raw material specifications and preparation process of Example 1, the high-temperature resistant adhesive was replaced with a conventional bisphenol A type epoxy resin adhesive. The types of other raw materials, the specifications of the mica paper layer and the reinforcing material layer, the coating parameters, the composite conditions, the baking process, and the slitting specifications were all exactly the same as in Example 1, resulting in comparative samples.

[0034] Comparative Example 4: A comparative sample was prepared using a single-stage curing process based on existing technology: The segmented baking curing was replaced with a single heating to 215 degrees Celsius and holding for 55 minutes. The types and amounts of other raw materials, the specifications of the mica paper layer and reinforcing material layer, the adhesive parameters, the lamination conditions, and the slitting specifications were all identical to those in Example 1, resulting in the comparative sample.

[0035] Comparative Example 5: A comparative sample was prepared using existing resin blends, but in proportions exceeding the scope of this invention: Based on the raw material specifications and preparation process of Example 1, 95 parts of methylphenyl silicone resin and 5 parts of phenyl vinyl silicone resin were used. The types and amounts of other raw materials, the specifications of the mica paper layer and the reinforcing material layer, the coating parameters, the composite conditions, the segmented baking regime, and the slitting specifications were all exactly the same as in Example 1, resulting in the comparative sample.

[0036] The high-temperature resistant insulating mica tape prepared by this invention is compatible with various types of cables used in the windings of high-end electrical equipment. These compatible cable types include QY-type polyimide enameled round copper wire, QZY-type polyimide enameled flat copper wire, QXY-type modified polyimide enameled round copper wire, JXN-type motor winding lead wire, and JXF-type fluoroplastic insulated motor winding lead wire. These cables are widely used in the winding structures of motors, transformers, reactors, and other equipment. The mica tape of this invention, with its H-class temperature resistance and excellent insulation, mechanical, and high-temperature stability, can achieve good compatibility and composite properties with these cables. The resulting winding insulation structure can meet the insulation protection requirements of high-end electrical equipment under high-temperature conditions. The combination of the compatible cable types with the mica tape of this invention can further improve the overall temperature resistance and structural stability of the electrical equipment windings. Performance testing and results analysis: The tests were conducted in accordance with GB / T5019-2017, GB / T1408-2018 and GB / T1303-2018 standards. The test items included temperature resistance rating, breakdown strength, tensile strength, volume resistivity and performance retention rate after aging at 250 degrees Celsius for 168 hours.

[0037] The test results are shown in Table 1 below: Table 1:

[0038] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A high-temperature resistant insulating mica tape, characterized in that, It is formed by the composite curing of a mica paper layer, a reinforcing material layer, and a high-temperature resistant adhesive coated on the bonding surfaces of the two; the high-temperature resistant adhesive includes an organosilicon resin compound, a ternary high-temperature resistant filler, a silane coupling agent, a curing agent, and a diluent. The organosilicon resin compound is composed of methylphenyl silicone resin and phenyl vinyl silicone resin, and the ternary high-temperature resistant filler is a mixture of nano-alumina, nano-magnesium oxide, and mica powder.

2. The high-temperature resistant insulating mica tape according to claim 1, characterized in that, The mica paper layer is phlogopite paper; the reinforcing material layer is alkali-free glass fiber cloth or polyimide film.

3. The high-temperature resistant insulating mica tape according to claim 1, characterized in that, The silane coupling agent is KH550 or KH560; the curing agent is an organotin curing agent or an amine curing agent; and the diluent is xylene.

4. The high-temperature resistant insulating mica tape according to claim 1, characterized in that, By weight, the high-temperature resistant adhesive comprises 100 parts of methyl phenyl silicone resin and phenyl vinyl silicone resin, 5-15 parts of nano alumina, 20-30 parts of nano magnesium oxide, 35-65 parts of mica powder, 2-4.5 parts of silane coupling agent, 3-6.5 parts of curing agent, and 18 parts of diluent.

5. A method for preparing the high-temperature resistant insulating mica tape according to any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Preparation of high temperature resistant adhesive: Mix methyl phenyl silicone resin and phenyl vinyl silicone resin, add diluent, stir until completely dissolved, add silane coupling agent and continue stirring, then add ternary high temperature resistant filler for high-speed dispersion, and finally add curing agent and stir to obtain high temperature resistant adhesive; (2) Composite molding: High-temperature resistant adhesive is coated on one side of the mica paper layer and the reinforcing material layer, and the composite is completed by hot pressing to obtain the composite blank; (3) Segmented baking and curing: The composite preform is baked at three different temperatures in sequence to complete the curing process and obtain the cured preform; (4) Slitting: The cured blank is slitted into strips to obtain the finished high-temperature resistant insulating mica tape.

6. The preparation method according to claim 5, characterized in that, In step (1), the stirring speed of the diluent after mixing methylphenyl silicone resin and phenyl vinyl silicone resin is 400 rpm; the high-speed dispersion speed after adding ternary high-temperature resistant filler is 1500 rpm.

7. The preparation method according to claim 5, characterized in that, In step (1), the stirring time after adding the silane coupling agent is 20 minutes; the high-speed dispersion time after adding the ternary high-temperature resistant filler is 45 minutes; and the stirring time after adding the curing agent is 30 minutes.

8. The preparation method according to claim 5, characterized in that, In step (2), the amount of high-temperature resistant adhesive applied to one side is 5-12 grams per square meter; the temperature of hot pressing is 70-100 degrees Celsius, the pressure is 0.3-0.6 MPa, and the time is 15-25 seconds.

9. The preparation method according to claim 5, characterized in that, In step (3), the temperature of the first stage of baking is 85-110 degrees Celsius and the holding time is 12-18 minutes; the temperature of the second stage of baking is 135-165 degrees Celsius and the holding time is 18-25 minutes; the temperature of the third stage of baking is 215-245 degrees Celsius and the holding time is 15-25 minutes.

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