A sprayable flame-retardant mica tape and its preparation method

Abstract

The present application discloses a sprayable flame-retardant mica tape and a preparation method thereof. A sprayable flame-retardant mica tape includes a glass fiber reinforcement layer, a mica layer, and a flame-retardant coating connected in sequence; the flame-retardant coating includes raw materials in the following weight ratio: organosilicon aqueous solution: diisopropyl adipate: magnesium hydroxide: ammonium carbonate = (80 - 100): (6 - 8): (20 - 30): (25 - 35); the mica layer includes raw materials in the following weight ratio: mica powder: organosilicon: quartz powder: montmorillonite powder = (65 - 75): (42 - 46): (16 - 24): (25 - 35); the glass fiber reinforcement layer is a glass fiber cloth. The sprayable flame-retardant mica tape prepared in the present application has excellent comprehensive performance and stronger flame-retardant performance.

Description

Technical Field

[0001] The present application relates to the technical field, and in particular to a sprayable flame-retardant mica tape and a preparation method thereof. Background Art

[0002] Mica materials have been widely used in the field of wire and cable insulation materials for a long time due to their excellent properties such as insulation and high temperature resistance. At present, the main process for producing mica paper in the market is coating, that is, after sizing the fiberglass cloth, it is laminated with mica paper, and then wound up after drying in an oven. To ensure the drying degree, this process requires a long coating line length, so it has high requirements for the production space. Moreover, there are many unstable factors in this process, such as the sizing method, drying temperature, sizing amount on the mica layer, etc., and the process control ability is poor. At the same time, due to the easy unevenness of mica paper during the mica layer forming process, the electrical insulation performance of mica paper is uneven.

[0003] In addition, since mica materials often use organic adhesives and are laminated with organic films to achieve the winding performance, their flame retardant performance is poor and cannot meet the requirements of cables and other materials with flame retardant requirements. Moreover, the mica tape produced by traditional coating is a multi-layer composite structure and there is a risk of delamination.

[0004] Therefore, there is a need for a mica tape with stable production process, uniform electrical insulation, good flame retardant performance and low delamination risk. Summary of the Invention

[0005] In order to solve at least one of the above technical problems and develop a mica tape with a stable production process, uniform electrical insulation, good flame retardant performance and low delamination risk, the present application provides a sprayable flame-retardant mica tape.

[0006] On the one hand, a sprayable flame-retardant mica tape provided by the present application includes a fiberglass reinforcement layer, a mica layer and a flame retardant coating connected in sequence;

[0007] The flame retardant coating includes raw materials in the following weight ratio: organosilicon aqueous solution: diisopropyl adipate: magnesium hydroxide: ammonium carbonate = (80 - 100):(6 - 8):(20 - 30):(25 - 35);

[0008] The mica layer includes raw materials in the following weight ratio: mica powder: organosilicon: quartz powder: montmorillonite powder = (65 - 75):(42 - 46):(16 - 24):(25 - 35);

[0009] The fiberglass reinforcement layer is a fiberglass cloth.

[0010] By adopting the above technical solutions, the sprayable flame-retardant mica tape prepared by the present application with specific raw materials and ratios has good appearance, no cracks, reverse adhesion, etc., and excellent and stable comprehensive performance. The use of the inorganic high-temperature resistant material mica and the reinforcing material fiberglass cloth endows the mica tape with excellent and stable insulation performance and heat and fire resistance, and the two are embedded and bonded tightly, reducing the probability of delamination. The flame-retardant coating can enhance the flame-retardant performance of the mica tape. Magnesium hydroxide can precipitate crystal water at high temperature, and ammonium carbonate can decompose at high temperature to generate carbon dioxide, ammonia, and water, which can effectively prevent the combustion of the mica tape at high temperature and inhibit the spread of flames.

[0011] Optionally, the flame-retardant coating comprises raw materials in the following weight ratios: organosilicon aqueous solution: diisopropyl adipate: magnesium hydroxide: ammonium carbonate = 90:7:25:30.

[0012] Optionally, the mica layer comprises raw materials in the following weight ratios: mica powder: organosilicon: quartz powder: montmorillonite powder = 70:44:22:30.

[0013] By adopting the above technical solutions, the flame-retardant coating and mica layer prepared with specific ratios in the present application, and then the sprayable flame-retardant mica tape prepared therefrom, have good appearance, no cracks, reverse adhesion, etc., and excellent and stable comprehensive performance.

[0014] In a second aspect, the present application provides a method for preparing the above sprayable flame-retardant mica tape, comprising the following steps:

[0015] S1. Stir and mix the raw materials of the flame-retardant coating to prepare a flame-retardant coating liquid, and stir and mix the raw materials of the mica layer to prepare a mica slurry for standby;

[0016] S2. Spray the mica slurry obtained in step S1 onto one surface of the fiberglass cloth, and after drying, obtain a sprayable mica tape, wherein the mica slurry forms the mica layer;

[0017] S3. Coating the flame-retardant coating liquid on the side of the mica layer away from the fiberglass cloth by a curtain coating method to obtain a composite mica tape;

[0018] S4. Perform a drying treatment on the composite mica tape obtained in step S3, and after drying, wind it up to obtain a sprayable flame-retardant mica tape, wherein the flame-retardant coating liquid forms the flame-retardant coating.

[0019] By adopting the above technical solution, the preparation method adopted in this application pulps mica. Through the spraying process, the preparation process of the mica tape is made more stable, and the electrical insulation performance is more uniform. Moreover, the sprayed mica tape fits more closely with the reinforcing material fiberglass cloth, which belongs to an inlaid fit, greatly reducing the risk of delamination. And by preparing the flame-retardant layer liquid and laminating it on the surface of the mica tape to form a flame-retardant coating, the finally prepared sprayed flame-retardant mica tape has excellent comprehensive performance and excellent flame-retardant performance.

[0020] Optionally, in the step S1, the stirring speed ≥ 450 r / min and the stirring time ≥ 50 min.

[0021] Optionally, in the step S2, the spraying caliber is 2.5 mm and the spraying pressure is 0.1 - 0.3 MPa.

[0022] Optionally, in the step S2, the spraying pressure is 0.2 MPa.

[0023] Optionally, in the step S2, the spraying thickness > 0.12 mm. Before drying, the fiberglass cloth with mica slurry attached is passed through a slit with a gap of 0.12 mm.

[0024] By adopting the above technical solution, the mica slurry is sprayed evenly and stably, and the thickness of the mica layer is uniform, avoiding blockage of the spraying port due to too small a spraying port.

[0025] Optionally, in the step S3, during laminating, the moving speed of the sprayed mica tape is 3 m / min, the laminating gap is 0.02 mm, and the temperature of the laminating chamber is 80°C ± 10°C.

[0026] By adopting the above technical solution, the flame-retardant coating is flat and uniform, and blockage of the laminating port is avoided.

[0027] Optionally, in the step S4, four-stage drying process is adopted for drying. The temperature of the first-stage drying is 50 - 60°C, and the drying time is 1 - 2 min. The temperature of the second-stage drying is 100 - 120°C, and the drying time is 3 - 4 min. The temperature of the third-stage drying is 130 - 150°C, and the drying time is 2 - 3 min. The temperature of the fourth-stage drying is 80 - 100°C, and the drying time is 4 - 5 min.

[0028] By adopting the above technical solution, this application adopts a specific four-stage drying process, making the obtained sprayed flame-retardant mica tape dry completely, avoiding incomplete curing, reverse adhesion, and wrinkling of the mica tape due to too low temperature, and cracking and bubbling of the mica tape due to too high temperature, which will seriously affect the performance of the sprayed flame-retardant mica tape.

[0029] In summary, the present invention includes at least one of the following beneficial technical effects:

[0030] 1. The sprayable flame-retardant mica tape prepared by the present application using specific raw materials and ratios has excellent comprehensive performance. By using the inorganic high-temperature resistant material mica and the reinforcing material fiberglass cloth, the mica tape has excellent insulation performance and heat and fire resistance, and the two are embedded and bonded tightly, reducing the probability of delamination. The flame-retardant coating can enhance the flame-retardant performance of the mica tape. Magnesium hydroxide can precipitate crystal water at high temperatures, and ammonium carbonate can decompose at high temperatures to generate carbon dioxide, ammonia, and water, which can effectively prevent the combustion of the mica tape at high temperatures and inhibit the spread of flames.

[0031] 2. The preparation method adopted by the present application pulps mica. Through the spraying process, the preparation process of the mica tape is more stable, and the electrical insulation performance is more uniform. The sprayed mica tape is more tightly bonded to the reinforcing material fiberglass cloth, which belongs to an embedded bonding, greatly reducing the risk of delamination. And by preparing the flame-retardant layer liquid and laminating it on the surface of the mica tape to form a flame-retardant coating, the finally prepared sprayable flame-retardant mica tape has excellent comprehensive performance and excellent flame-retardant performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a schematic structural diagram of the sprayable flame-retardant mica tape in the embodiment of the present application.

[0033] Description of the reference numerals: 1, fiberglass reinforcing layer; 2, mica layer; 3, flame-retardant coating. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The following further describes the present application in detail with reference to the drawings and embodiments.

[0035] The present application designs a sprayable flame-retardant mica tape, including a fiberglass reinforcing layer, a mica layer, and a flame-retardant coating connected in sequence;

[0036] The flame-retardant coating includes raw materials in the following weight ratios, organosilicon aqueous solution: diisopropyl adipate: magnesium hydroxide: ammonium carbonate = (80 - 100):(6 - 8):(20 - 30):(25 - 35);

[0037] The mica layer includes raw materials in the following weight ratios, mica powder: organosilicon: quartz powder: montmorillonite powder = (65 - 75):(42 - 46):(16 - 24):(25 - 35);

[0038] The fiberglass reinforcing layer 1 is a fiberglass cloth.

[0039] The sprayable flame-retardant mica tape of the present application is prepared by the following method, including the following steps:

[0040] S1. Stir and mix the raw materials of the flame-retardant coating to prepare a flame-retardant coating liquid, and stir and mix the raw materials of the mica layer to prepare a mica slurry for standby;

[0041] S2. Spray the mica slurry prepared in step S1 onto one surface of the fiberglass cloth, and after drying, obtain a sprayed mica tape, wherein the mica slurry forms the mica layer 2;

[0042] S3. Coating the flame retardant coating liquid on the side of the mica layer 2 away from the fiberglass cloth by means of film laminating to obtain a composite mica tape;

[0043] S4. Perform a drying treatment on the composite mica tape prepared in step S3, and after drying, wind it up to obtain a sprayed flame retardant mica tape, wherein the flame retardant coating liquid forms the flame retardant coating 3.

[0044] Mica materials have been widely used in the field of wire and cable insulation materials for a long time due to their excellent properties such as insulation and high temperature resistance. At present, the main process for producing mica paper in the market is coating, that is, after gluing the fiberglass cloth and laminating it with mica paper, and then winding it up after drying in an oven. To ensure the drying degree, this process requires a long coating line length, so it has high requirements for production space. Moreover, there are many unstable factors in this process, such as the gluing method, drying temperature, the amount of glue on the mica paper, etc., and the process control ability is poor. At the same time, due to the unevenness of the mica paper during the papermaking process, the electrical insulation performance of the mica paper is uneven.

[0045] In addition, since mica materials often use organic adhesives and are laminated with organic films to achieve the winding performance, their flame retardant performance is poor and cannot meet the requirements of cables and other materials with flame retardant requirements. Moreover, the mica tape produced by traditional coating is a multi-layer composite structure and there is a risk of delamination.

[0046] Based on the above problems, the inventors of the present application designed the technical solution of the present application. Through the spraying process, the mica slurry is sprayed on the fiberglass cloth, and the sprayed mica layer is more closely attached to the reinforcing material fiberglass cloth, which belongs to inlaid lamination, and the delamination risk is greatly reduced. And by preparing a flame retardant layer coating and performing coating treatment in a slit coating manner, a flame retardant coating is formed on the surface of the mica layer instead of an organic film to prepare a coated flame retardant mica tape, so that the mica tape has a flame retardant effect.

[0047] The raw material models of the present application are as follows. Unless otherwise specified, the raw materials used in the present application are all commercially available:

[0048] E-glass fiber cloth: brand, Lebang, product number 02;

[0049] Mica powder: purity ≥ 99.99%;

[0050] Organic silicone: brand, Dazexi, product number D6702;

[0051] Quartz powder: purity ≥ 99.99%, 1250 mesh;

[0052] Montmorillonite powder: purity ≥ 99.99%, 800 mesh;

[0053] Organic silicone water: purity 98%;

[0054] Diisopropyl adipate: purity 99%;

[0055] Magnesium hydroxide: purity 99%;

[0056] Ammonium carbonate: brand, Merck, number M17972. Specific embodiments

[0058] Examples 1 - 5

[0059] The specific content of the raw materials in Examples 1 - 5 is shown in Table 1 below.

[0060] Table 1 Specific content of raw materials in Examples 1 - 5

[0061]

[0062] Example 1

[0063] A preparation method of a spray - coated flame - retardant mica tape, comprising the following steps:

[0064] S1. Stir and mix the raw materials of the flame - retardant coating to prepare a flame - retardant coating liquid, and stir and mix the raw materials of the mica layer to prepare a mica slurry for standby;

[0065] S2. Spray the mica slurry obtained in step S1 onto one surface of the fiberglass cloth, and after drying, obtain a spray - coated mica tape, wherein the mica slurry forms the mica layer 2;

[0066] S3. Coating the flame - retardant coating liquid on the side of the mica layer 2 away from the fiberglass cloth by means of film - casting to obtain a composite mica tape;

[0067] S4. Perform a drying treatment on the composite mica tape obtained in step S3, and after drying, wind it up to obtain a spray - coated flame - retardant mica tape, wherein the flame - retardant coating liquid forms the flame - retardant coating 3;

[0068] Among them, in step S1, the stirring speed is 500 r / min and the stirring time is 55 min;

[0069] In step S2, the spraying diameter is 2.5 mm and the spraying pressure is 0.2 MPa;

[0070] In step S3, the coating gap is 0.02 mm, the moving speed of the sprayed mica tape is 3 m / min, and the temperature of the coating chamber is 80°C; in step S4, a four-stage drying process is used for drying. The temperature of the first-stage drying is 55°C, and the drying time is 1 min. The temperature of the second-stage drying is 110°C, and the drying time is 4 min. The temperature of the third-stage drying is 140°C, and the drying time is 3 min. The temperature of the fourth-stage drying is 90°C, and the drying time is 4 min.

[0071] Example 2

[0072] A preparation method of a sprayed flame-retardant mica tape includes the following steps:

[0073] S1. Stir and mix the raw materials of the flame-retardant coating to prepare a flame-retardant coating liquid, and stir and mix the raw materials of the mica layer to prepare a mica slurry for standby;

[0074] S2. Spray the mica slurry prepared in step S1 onto one surface of a fiberglass cloth, and after drying, a sprayed mica tape is obtained. Among them, the mica slurry forms the mica layer;

[0075] S3. Coat the flame-retardant coating liquid on the side of the mica layer away from the fiberglass cloth by means of coating to obtain a composite mica tape;

[0076] S4. Dry the composite mica tape prepared in step S3, and after drying, wind it up to obtain a sprayed flame-retardant mica tape. Among them, the flame-retardant coating liquid forms the flame-retardant coating;

[0077] Among them, in step S1, the stirring speed is 450 r / min, and the stirring time is 80 min;

[0078] In step S2, the spraying diameter is 2.5 mm, and the spraying pressure is 0.15 MPa;

[0079] In step S3, the coating gap is 0.02 mm, the moving speed of the sprayed mica tape is 3 m / min, and the temperature of the coating chamber is 70°C; in step S4, a four-stage drying process is used for drying. The temperature of the first-stage drying is 50°C, and the drying time is 1 min. The temperature of the second-stage drying is 120°C, and the drying time is 3 min. The temperature of the third-stage drying is 130°C, and the drying time is 3 min. The temperature of the fourth-stage drying is 85°C, and the drying time is 4 min.

[0080] Example 3

[0081] A preparation method of a sprayed flame-retardant mica tape includes the following steps:

[0082] S1. Stir and mix the raw materials of the flame-retardant coating to prepare a flame-retardant coating liquid, and stir and mix the raw materials of the mica layer to prepare a mica slurry for standby;

[0083] S2. Spray the mica slurry prepared in step S1 onto one surface of the fiberglass cloth, and after drying, obtain a sprayed mica tape, wherein the mica slurry forms the mica layer;

[0084] S3. Coat the flame retardant coating liquid on the side of the mica layer away from the fiberglass cloth by means of curtain coating to obtain a composite mica tape;

[0085] S4. Perform a drying treatment on the composite mica tape prepared in step S3, and after drying, wind it up to obtain a sprayed flame retardant mica tape, wherein the flame retardant coating liquid forms the flame retardant coating;

[0086] Among them, in step S1, the stirring speed is 470 r / min and the stirring time is 70 min;

[0087] In step S2, the spraying orifice diameter is 2.5 mm and the spraying pressure is 0.25 MPa;

[0088] In step S3, the curtain coating gap is 0.02 mm, the moving speed of the sprayed mica tape is 3 m / min, and the temperature of the curtain coating chamber is 75 °C; in step S4, a four-stage drying process is used for drying. The temperature of the first stage of drying is 60 °C, the drying time is 2 min, the temperature of the second stage of drying is 115 °C, the drying time is 3 min, the temperature of the third stage of drying is 135 °C, the drying time is 2 min, and the temperature of the fourth stage of drying is 95 °C, and the drying time is 5 min.

[0089] Example 4

[0090] A preparation method of a sprayed flame retardant mica tape, comprising the following steps:

[0091] S1. Stir and mix the raw materials of the flame retardant coating to prepare a flame retardant coating liquid, and stir and mix the raw materials of the mica layer to prepare a mica slurry for standby;

[0092] S2. Spray the mica slurry prepared in step S1 onto one surface of the fiberglass cloth, and after drying, obtain a sprayed mica tape, wherein the mica slurry forms the mica layer;

[0093] S3. Coat the flame retardant coating liquid on the side of the mica layer away from the fiberglass cloth by means of curtain coating to obtain a composite mica tape;

[0094] S4. Perform a drying treatment on the composite mica tape prepared in step S3, and after drying, wind it up to obtain a sprayed flame retardant mica tape, wherein the flame retardant coating liquid forms the flame retardant coating;

[0095] Among them, in step S1, the stirring speed is 560 r / min and the stirring time is 50 min;

[0096] In step S2, the spraying orifice diameter is 2.5 mm and the spraying pressure is 0.11 MPa;

[0097] In step S3, the film coating gap is 0.02 mm, the moving speed of the sprayed mica tape is 3 m / min, and the temperature of the film coating chamber is 85°C; in step S4, a four-stage drying process is adopted for drying. The temperature of the first-stage drying is 57°C and the drying time is 2 min. The temperature of the second-stage drying is 100°C and the drying time is 4 min. The temperature of the third-stage drying is 145°C and the drying time is 2 min. The temperature of the fourth-stage drying is 100°C and the drying time is 4 min.

[0098] Example 5

[0099] A preparation method of a sprayed flame-retardant mica tape, comprising the following steps:

[0100] S1. Stir and mix the raw materials of the flame-retardant coating to prepare a flame-retardant coating liquid, and stir and mix the raw materials of the mica layer to prepare a mica slurry for standby;

[0101] S2. Spray the mica slurry prepared in step S1 onto one surface of the fiberglass cloth, and after drying, obtain a sprayed mica tape, wherein the mica slurry forms the mica layer;

[0102] S3. Coating the flame-retardant coating liquid on the side of the mica layer away from the fiberglass cloth by means of film coating to obtain a composite mica tape;

[0103] S4. Perform drying treatment on the composite mica tape prepared in step S3, and after drying, wind it up to obtain a sprayed flame-retardant mica tape, wherein the flame-retardant coating liquid forms the flame-retardant coating.

[0104] Among them, in step S1, the stirring speed is 520 r / min and the stirring time is 60 min;

[0105] In step S2, the spraying orifice diameter is 2.5 mm and the spraying pressure is 0.3 MPa;

[0106] In step S3, the film coating gap is 0.02 mm, the moving speed of the sprayed mica tape is 3 m / min, and the temperature of the film coating chamber is 90°C; in step S4, a four-stage drying process is adopted for drying. The temperature of the first-stage drying is 53°C and the drying time is 2 min. The temperature of the second-stage drying is 105°C and the drying time is 3 min. The temperature of the third-stage drying is 150°C and the drying time is 3 min. The temperature of the fourth-stage drying is 80°C and the drying time is 5 min.

[0107] Comparative Example 1-28

[0108] Comparative Example 1

[0109] Based on Example 1, except that in step S1, the stirring speed is 400 r / min, the other components and preparation method are the same as those in Example 1.

[0110] Comparative Example 2

[0111] Based on Example 1, except that in step S1, the stirring time is 40 min, the other components and preparation method are the same as those in Example 1.

[0112] Comparative Example 3

[0113] Based on Example 1, except that in step S2, the spraying aperture is 2 mm, the other components and preparation method are the same as those in Example 1.

[0114] Comparative Example 4

[0115] Based on Example 1, except that in step S2, the spraying aperture is 3 mm, the other components and preparation method are the same as those in Example 1.

[0116] Comparative Example 5

[0117] Based on Example 1, except that in step S2, the spraying pressure is 0.05 MPa, the other components and preparation method are the same as those in Example 1.

[0118] Comparative Example 6

[0119] Based on Example 1, except that in step S2, the spraying pressure is 0.4 MPa, the other components and preparation method are the same as those in Example 1.

[0120] Comparative Example 7

[0121] Based on Example 1, except that in step S3, the film laminating speed is 3.5 m / min, the other components and preparation method are the same as those in Example 1.

[0122] Comparative Example 8

[0123] Based on Example 1, except that in step S3, the film laminating speed is 2.5 m / min, the other components and preparation method are the same as those in Example 1.

[0124] Comparative Example 9

[0125] Based on Example 1, except that in step S3, the film laminating cavity temperature is 65 °C, the other components and preparation method are the same as those in Example 1.

[0126] Comparative Example 10

[0127] Based on Example 1, except that in step S3, the temperature of the coating cavity is 95°C, the other components and the preparation method are the same as those in Example 1.

[0128] Comparative Example 11

[0129] Based on Example 1, except that in the drying process of step S4, the first-stage drying temperature is 45°C, the second-stage drying temperature is 95°C, the third-stage drying temperature is 120°C, and the fourth-stage drying temperature is 70°C, the other components and the preparation method are the same as those in Example 1.

[0130] Comparative Example 12

[0131] Based on Example 1, except that in the drying process of step S4, the first-stage drying temperature is 70°C, the second-stage drying temperature is 135°C, the third-stage drying temperature is 160°C, and the fourth-stage drying temperature is 105°C, the other components and the preparation method are the same as those in Example 1.

[0132] Comparative Example 13

[0133] Based on Example 1, except that the content of mica powder in the mica layer is 60 g, the other components and the preparation method are the same as those in Example 1.

[0134] Comparative Example 14

[0135] Based on Example 1, except that the content of mica powder in the mica layer is 80 g, the other components and the preparation method are the same as those in Example 1.

[0136] Comparative Example 15

[0137] Based on Example 1, except that the content of silicone rubber in the mica layer is 35 g, the other components and the preparation method are the same as those in Example 1.

[0138] Comparative Example 16

[0139] Based on Example 1, except that the content of silicone rubber in the mica layer is 50 g, the other components and the preparation method are the same as those in Example 1.

[0140] Comparative Example 17

[0141] Based on Example 1, except that the content of quartz powder in the mica layer is 10 g, the other components and the preparation method are the same as those in Example 1.

[0142] Comparative Example 18

[0143] Based on Example 1, except that the content of quartz powder in the mica layer is 30 g, the other components and the preparation method are the same as those in Example 1.

[0144] Comparative Example 19

[0145] Based on Example 1, except that the montmorillonite powder content in the mica layer is 15 g, the other components and the preparation method are the same as those in Example 1.

[0146] Comparative Example 20

[0147] Based on Example 1, except that the montmorillonite powder content in the mica layer is 40 g, the other components and the preparation method are the same as those in Example 1.

[0148] Comparative Example 21

[0149] Based on Example 1, except that the organosilicon aqueous solution content in the flame retardant coating is 70 g, the other components and the preparation method are the same as those in Example 1.

[0150] Comparative Example 22

[0151] Based on Example 1, except that the organosilicon aqueous solution content in the flame retardant coating is 110 g, the other components and the preparation method are the same as those in Example 1.

[0152] Comparative Example 23

[0153] Based on Example 1, except that the diisopropyl adipate content in the flame retardant coating is 3 g, the other components and the preparation method are the same as those in Example 1.

[0154] Comparative Example 24

[0155] Based on Example 1, except that the diisopropyl adipate content in the flame retardant coating is 10 g, the other components and the preparation method are the same as those in Example 1.

[0156] Comparative Example 25

[0157] Based on Example 1, except that the magnesium hydroxide content in the flame retardant coating is 15 g, the other components and the preparation method are the same as those in Example 1.

[0158] Comparative Example 26

[0159] Based on Example 1, except that the magnesium hydroxide content in the flame retardant coating is 40 g, the other components and the preparation method are the same as those in Example 1.

[0160] Comparative Example 27

[0161] Based on Example 1, except that the ammonium carbonate content in the flame retardant coating is 15 g, the other components and the preparation method are the same as those in Example 1.

[0162] Comparative Example 28

[0163] Based on Example 1, except that the ammonium carbonate content in the flame retardant coating is 40 g, the other components and the preparation method are the same as those in Example 1.

[0164] Experimental detection

[0165] Detection items and methods Thickness: Randomly take 10 places on the mica tape, measure the thickness at these 10 places to obtain the maximum thickness difference, and use this to detect whether the thickness of the mica tape is uniform, so as to know whether the electrical insulation of the mica tape is uniform;

[0166] Insulation resistance: Detect the insulation resistance of the mica tape according to the standard of "GB / T 3048.5-2007 Test methods for electrical cable and optical fiber cable - Part 5: Insulation resistance test";

[0167] Voltage withstand: Detect the voltage withstand performance of the mica tape according to the standard of "GB / T 5019.10-2022 Mica-based insulating materials - Part 10: Mica tapes for fire-resistant safety cables" (measure after 5 minutes at a high temperature of 800°C);

[0168] Fire resistance performance: Detect the fire resistance performance of the mica tape according to the standard of "GB / T 19216.11-2003 Test for circuit integrity of electric cables or optical cables under fire conditions";

[0169] Flame retardant performance: Place the mica tape vertically downward in a windless test chamber, use a blowtorch to ignite the specimen, and observe and record whether the mica tape is flame retardant, the length of flame spread, the time of self-extinguishing of the flame, and whether there are dripping objects;

[0170] Appearance of mica tape: Observe the appearance of the mica tape at room temperature, and check whether there are any defective phenomena such as bubbles on the surface, cracks on the surface, and wrinkles on the surface of the mica tape, which result in uneven surface.

[0171] Perform performance detection on the sprayed flame retardant mica tapes provided in Examples 1-6 and Comparative Examples 1-28, and record the detection results in Table 2 below.

[0172] Table 2 Performance detection data

[0173]

[0174]

[0175]

[0176] Comparative Example 29

[0177] The difference between Comparative Example 29 and Example 1 is that the mica tape prepared in this comparative example has no flame retardant coating.

[0178] Comparative Example 30

[0179] Comparative Example 30 is any commercially available three-in-one mica tape.

[0180] The flame retardant properties of the spray-coated flame retardant mica tapes provided in Examples 1-6 and Comparative Examples 29-30 were tested, and the test results are shown in Table 3 below.

[0181] Table 3 Test Results of Flame Retardant Properties

[0182] Flame retardant or not Spread length Self-extinguishing time Dripping matter Example 1 Yes 0 (No spread) 0 (Extinguished immediately after removing from fire) None Example 2 Yes 0 (No spread) 0 (Extinguished immediately after removing from fire) None Example 3 Yes 0 (No spread) 0 (Extinguished immediately after removing from fire) None Example 4 Yes 0 (No spread) 0 (Extinguished immediately after removing from fire) None Example 5 Yes 0 (No spread) 0 (Extinguished immediately after removing from fire) None Comparative Example 29 No 15 cm 12s There are dripping matters Comparative Example 30 No 20 cm 15s There are dripping matters

[0183] As can be seen from Examples 1-5 and Table 2, the preparation process of the mica tape prepared in this application is stable, uniform and flat, the electrical insulation performance is uniform, and the comprehensive performance is good. When the flame retardant coating includes the following raw materials in weight ratio: silicone aqueous solution: diisopropyl adipate: magnesium hydroxide: ammonium carbonate = 90:7:25:30, and the mica layer includes the following raw materials in weight ratio: mica powder: silicone rubber: quartz powder: montmorillonite powder = 70:44:22:30, the comprehensive performance of the spray-coated flame retardant mica tape prepared is better.

[0184] As can be seen from Examples 1-5, Comparative Examples 1-2 and Table 2, when the stirring speed is lower than 450 r / min, the uniformity of the sprayed mica slurry is poor, the raw materials are not stirred evenly, and the performance of the prepared mica tape is unstable; when the stirring time is lower than 50 min, the uniformity of the mica slurry is poor, especially montmorillonite cannot be stirred evenly with the mica slurry, and the comprehensive performance of the prepared mica tape is poor.

[0185] As can be seen from Examples 1-5, Comparative Examples 3-4 and Table 2, when the spraying diameter is greater than 2.5 mm, the sprayed mica layer is uneven; when it is less than 2.5 mm, the spraying port is easily blocked, and the comprehensive performance of the prepared mica tape is poor.

[0186] As can be seen from Examples 1-5, Comparative Examples 5-6 and Table 2, when the spraying pressure is greater than 0.3 MPa, the thickness of the sprayed mica layer is uneven; when it is less than 0.1 MPa, orange peel appears on the sprayed mica layer, and the comprehensive performance of the prepared mica tape is poor.

[0187] As can be seen from Examples 1-5, Comparative Examples 7-8 and Table 2, when the film laminating speed is higher than 3 m / min, the flame retardant coating is uneven and not flat; when the speed is lower than 3 m / min, the glue liquid accumulates at the gaps and solidifies easily, resulting in blockage, and the comprehensive performance of the prepared mica tape is poor.

[0188] As can be seen from Examples 1-5, Comparative Examples 9-10 and Table 2, when the temperature of the film laminating chamber is too high, the flame retardant coating liquid is easily blocked at the film laminating port; when the temperature is too low, the fluidity of the silicone aqueous solution is poor, and the surface treatment of the mica tape is uneven, and the comprehensive performance of the prepared mica tape is poor.

[0189] As can be seen from Examples 1-5, Comparative Examples 11-12 and Table 2, when the drying temperature is too low, the adhesive solution is not dried, the silicone aqueous solution is not cured, and the surface of the mica tape is wrinkled. When the temperature is too high, bubbles and cracks appear on the surface of the mica tape, and the comprehensive performance of the prepared mica tape is poor.

[0190] As can be seen from Examples 1-5, Comparative Examples 13-28 and Table 2, when the raw materials of the mica layer and the flame retardant layer are lower or higher than the value range, the comprehensive performance of the prepared mica tape is poor and does not meet the requirements of actual use.

[0191] As can be seen from Examples 1-5, Comparative Examples 29-30 and Table 3, the spray flame retardant mica tape prepared in this application has excellent flame retardant effect, can effectively prevent the combustion of the mica tape at high temperature, and inhibit the spread of flames.

[0192] The above are all preferred embodiments of this application. The protection scope of this application is not limited by this. Therefore, all equivalent changes made according to the structure, shape, and principle of this application should be covered within the protection scope of this application.

Claims

1. A preparation method of a sprayed flame-retardant mica tape, characterized in that The flame-retardant mica tape includes a glass fiber reinforcement layer, a mica layer, and a flame-retardant coating that are connected in sequence; the flame-retardant coating includes raw materials in the following weight ratio: silicone aqueous solution: diisopropyl adipate: magnesium hydroxide: ammonium carbonate = (80 - 100): (6 - 8): (20 - 30): (25 - 35); The mica layer includes raw materials in the following weight ratio: mica powder: silicone organic: quartz powder: montmorillonite powder = (65 - 75): (42 - 46): (16 - 24): (25 - 35); The glass fiber reinforcement layer is a glass fiber cloth; It includes the following preparation steps: S1. Stir and mix the raw materials of the flame-retardant coating to prepare a flame-retardant coating liquid, and stir and mix the raw materials of the mica layer to prepare a mica slurry for standby. The stirring speed is ≥450 r / min, and the stirring time is ≥50 min; S2. Spray the mica slurry obtained in step S1 onto one surface of the glass fiber cloth, and after drying, obtain a sprayed mica tape. Among them, the mica slurry forms the mica layer, the spraying orifice diameter is 2.5 mm, and the spraying pressure is 0.1 - 0.3 MPa; S3. Coating the flame-retardant coating liquid on the side of the mica layer away from the glass fiber cloth by means of curtain coating to obtain a composite mica tape. During curtain coating, the moving speed of the sprayed mica tape is 3 m / min, the curtain coating gap is 0.02 mm, and the temperature of the curtain coating chamber is 80°C ± 10°C; S4. Perform a drying treatment on the composite mica tape obtained in step S3, and after drying, wind it up to obtain a sprayed flame-retardant mica tape. Among them, the flame-retardant coating liquid forms the flame-retardant coating, and a four-stage drying process is used for drying. The temperature of the first-stage drying is 50 - 60°C, and the drying time is 1 - 2 min. The temperature of the second-stage drying is 100 - 120°C, and the drying time is 3 - 4 min. The temperature of the third-stage drying is 130 - 150°C, and the drying time is 2 - 3 min. The temperature of the fourth-stage drying is 80 - 100°C, and the drying time is 4 - 5 min.

2. The preparation method of the sprayable flame-retardant mica tape according to claim 1, characterized in that, The flame-retardant coating includes raw materials in the following weight ratio: silicone aqueous solution: diisopropyl adipate: magnesium hydroxide: ammonium carbonate = 90: 7: 25:

30.

3. The preparation method of the sprayable flame-retardant mica tape according to claim 1, characterized in that, The mica layer includes raw materials in the following weight ratio: mica powder: silicone organic: quartz powder: montmorillonite powder = 70: 44: 22:

30.

4. A flame-retardant mica tape obtained by the preparation method of the sprayed flame-retardant mica tape according to any one of claims 1 - 3.

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