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CN-122025264-A - Mica tape special for fire-resistant cable and forming process thereof

CN122025264ACN 122025264 ACN122025264 ACN 122025264ACN-122025264-A

Abstract

The invention relates to the technical field of cable materials, in particular to a mica tape special for a fire-resistant cable and a forming process thereof, which are composed of, by mass, 65-80 parts of synthetic mica powder, 12-22 parts of a composite bonding system, 8% of a zinc 2-ethylhexanoate curing agent in total mass of the composite bonding system, 22 g per square meter of alkali-free glass fiber cloth reinforced base material with the thickness of 0.028 mm in unit area, and 5-6 parts of an epoxy modified resin composition object surface adhesive layer. The mica tape special for the fire-resistant cable and the forming process thereof provided by the invention are systematically optimized aiming at a plurality of defects in the prior art, so that the spanning type improvement of the comprehensive performance of the fire-resistant mica tape is realized, and the fire-resistant cable has obvious technical advantages and practical values.

Inventors

  • LI JIAQI
  • LI LIWEI
  • YANG QIANPING
  • Hu Panle
  • ZHOU YINPING
  • LI LIXING

Assignees

  • 廊坊讯途电线电缆材料有限公司

Dates

Publication Date
20260512
Application Date
20260313

Claims (10)

  1. 1. A mica tape special for a fire-resistant cable is characterized by comprising, by mass, 65-80 parts of synthetic mica powder, 12-22 parts of a composite bonding system, a zinc 2-ethylhexanoate curing agent accounting for 8% of the total mass of the composite bonding system, 22 grams per square meter of alkali-free glass fiber cloth reinforcing base material with the thickness of 0.028 millimeter, and 5-6 parts of an epoxy modified resin composition object surface adhesive layer, wherein the composite bonding system is formed by compounding organic silicon resin and epoxy modified resin, the mass ratio of the organic silicon resin to the epoxy modified resin is 1:1-3:1, the synthetic mica powder is prepared by carrying out magnetic separation by 12000 Gaussian magnetic fields to remove iron, hydraulic classification, hot-pressing stripping at 300 ℃ and wet-making, the sheet diameter D50 of the synthetic mica powder is 35-45 microns, and the solid content of the epoxy modified resin composition is 10-12%.
  2. 2. The mica tape special for fire-resistant cables according to claim 1, further comprising 3 parts of nano silica filler surface-modified by diphenylmethane diisocyanate, wherein the addition amount of the modifier diphenylmethane diisocyanate is 0.15 part, and the particle size of the nano silica filler is 20 nanometers.
  3. 3. The mica tape special for the fire-resistant cable according to claim 1, wherein the reinforcing substrate is replaced by a composite substrate with the total thickness of 0.03 mm, the composite substrate is formed by compounding alkali-free glass fiber cloth with the thickness of 0.028 mm and polyimide film with the thickness of 0.002 mm in a hot-pressing mode, the mica tape special for the fire-resistant cable further comprises 6-8 parts of micro boron nitride-nano graphene composite functional filler with the surface modified by diphenylmethane diisocyanate, the adding amount of the diphenylmethane diisocyanate serving as a modifier is 0.3-0.4 part, the particle size of the micro boron nitride is 1 micrometer, and the thickness of the nano graphene is 0.8 nanometer.
  4. 4. The mica tape special for the fire-resistant cable according to claim 3, wherein in the micro boron nitride-nano graphene composite functional filler, the mass ratio of the micro boron nitride to the nano graphene is 5:1.
  5. 5. The fire resistant cable-specific mica tape as recited in any one of claims 1 to 4 wherein the mica tape has a surface coated with 0.5 grams per square meter of phenyl o-hydroxybenzoate ultraviolet resistant coating.
  6. 6. A forming process for preparing the mica tape special for the fire-resistant cable of claim 1, which is characterized by comprising the following steps: (1) The mica powder pretreatment, namely carrying out magnetic separation and iron removal on natural mica by using a 12000-Gauss magnetic field, carrying out hydraulic classification, carrying out hot pressing stripping at 300 ℃ and 0.8 megapascal, and carrying out wet papermaking to prepare synthetic mica paper; (2) Mixing organic silicon resin and epoxy modified resin according to a mass ratio of 1:1 to 3:1, adding a zinc 2-ethylhexanoate curing agent accounting for 8% of the total mass of the composite bonding system, stirring for 60 minutes at a rotating speed of 500 revolutions per minute, regulating the viscosity of the system to 3000 mPa s by adopting polyether polyol 330N, wherein the adding amount of the polyether polyol 330N is 2% -3% of the total mass of the composite bonding system, and obtaining the composite bonding system; (3) Coating and compounding, namely coating a compound bonding system on one side of the synthetic mica paper by adopting a slit extrusion coater according to the coating amount of 10 grams per square meter, and carrying out hot pressing lamination on the synthetic mica paper and alkali-free glass fiber cloth for 20 seconds under the conditions of 120 ℃ and 0.3 megapascals; (4) Coating the surface adhesive layer by coating the epoxy modified resin composition on the other side of the synthetic mica paper in a coating amount of 5 grams per square meter; (5) Sectional curing, namely pre-curing for 40 minutes at 100 ℃ by adopting 2.5 micrometer infrared wavelength, and then final curing for 60 minutes at 180 ℃ by adopting hot air to ensure that the crosslinking degree of the adhesive layer reaches 92%; (6) And (3) post-treatment, namely cutting the cured base material into 30 mm wide pieces by laser, vacuum packaging the base material at a vacuum degree of-0.09 megapascals, and placing a silica gel drying agent in the package, wherein the adding amount of the silica gel drying agent is 2 grams per square meter of strip.
  7. 7. The molding process of claim 6, wherein 3 parts of nano silica filler modified by diphenylmethane diisocyanate is added before the viscosity is adjusted in step (2), the mixture is dispersed for 30 minutes by using 600 watts ultrasonic, and then stirred at 600 rpm for 80 minutes, the viscosity of the mixture is adjusted to 3200 mpa sec, the coating amount of the composite bonding system in step (3) is 12 grams per square meter, the hot press bonding condition is 130 degrees celsius, 0.3 mpa, 25 seconds, the coating amount of the epoxy modified resin composition in step (4) is 5.5 grams per square meter, the pre-curing condition in step (5) is 110 degrees celsius, 35 minutes, the final curing condition is 190 degrees celsius, 50 minutes, the crosslinking degree of the adhesive layer reaches 93%, and the adding amount of the silica gel drying agent in step (6) is 3 grams per square meter of the tape.
  8. 8. The molding process according to claim 6, wherein when the mica tape of claim 3 is prepared, the alkali-free glass fiber cloth and the polyimide film are thermally pressed and bonded for 30 seconds at 150 ℃ and 0.5 mpa, 6-8 parts of micro boron nitride-nano graphene composite functional filler modified by diphenylmethane diisocyanate is added in the step (2), 600 watts of ultrasonic dispersion is adopted for 30 minutes, the mixture is stirred for 90 minutes at 700 revolutions per minute, the viscosity of the system is regulated to 3300 mpa s, the coating amount of the composite bonding system in the step (3) is 13 grams per square meter, the composite bonding system and the polyimide film are thermally pressed and bonded for 30 seconds at 140 ℃ and 0.4 mpa, the coating amount of the epoxy modified resin composition in the step (4) is 6 grams per square meter, the pre-curing condition in the step (5) is 120 ℃ and 30 minutes, the final curing condition is 200 ℃ and 45 minutes, the crosslinking degree of the adhesive layer reaches 94%, the slitting width in the step (6) is 35 millimeters, the hydroxy benzoate is sprayed for 0.5 grams per square meter, the adhesive layer is sprayed for 0.09 grams per square meter, and the vacuum-sealed tape is further packaged.
  9. 9. The molding process of claim 8, wherein when the mica tape of claim 4 is prepared, 6 parts of composite functional filler is added in step (2), 800 watts of ultrasonic dispersion is adopted for 35 minutes, stirring is carried out at a rotating speed of 800 revolutions per minute for 70 minutes, the viscosity of the system is regulated to 3400 millipascals, in step (3), a digital twin system is adopted for controlling the linear speed to 25 meters per minute, a simulation model is built by the digital twin system based on real-time operation parameters of a coating machine and feedback data of the coating thickness, the pressure and the discharge speed of the coating machine are adaptively regulated, the coating amount of the composite bonding system is 14 grams per square meter, the hot pressing bonding condition is 145 ℃ and 0.45 megapascals and 32 seconds, the coating amount of the epoxy modified resin composition in step (4) is 5.8 grams per square meter, in step (5), the cross-linking degree is monitored on line at a characteristic peak position of 1720cm -1 by adopting an FTIR spectrum method, the curing parameters are regulated in real time according to the characteristic peak absorbance change, the curing conditions are 115 ℃ and 32 minutes, the curing conditions are 210 ℃ and 48 minutes, the cross-linking degree is detected by the adhesive layer is 95 mm, and the vacuum package is carried out at a vacuum package thickness of 0.001 mm and the vacuum package is 0mm per square meter.
  10. 10. The molding process according to any one of claims 6 to 9, wherein the epoxy-modified resin composition has a solids content that is adapted in positive correlation with the coating amount, the solids content of the epoxy-modified resin composition being increased by 0.5% for every 0.5 gram per square meter increase in the coating amount.

Description

Mica tape special for fire-resistant cable and forming process thereof Technical Field The invention relates to the technical field of cable materials, in particular to a mica tape special for a fire-resistant cable and a forming process thereof. Background The fire-resistant mica tape is used as a core insulating fire-resistant component of a fire-resistant cable, the performance of the fire-resistant mica tape directly determines the operation stability of the cable in a high-temperature fire environment, and the fire-resistant mica tape is widely applied to the fields of power transmission, rail transit and the like with strict requirements on fire safety. At present, the production and preparation of the existing fire-resistant mica tape still has a plurality of short plates with technology, and the high-specification use requirement of the high-voltage cable is difficult to meet. The bonding system of the existing product is mostly prepared by adopting a single resin, has inherent contradiction between temperature resistance and bonding force, has insufficient bonding strength if the temperature resistance is emphasized, is easy to peel between layers, has reduced temperature resistance if the bonding force is improved, has low crosslinking degree after curing, and has obvious mechanical property attenuation after heat aging. In the aspect of filler application, the traditional scheme is mostly and directly added with unmodified fillers, so that agglomeration phenomenon is easy to occur, the bonding force between the modified fillers and a resin interface is weak, the performances of heat conduction, flame retardance and the like cannot be effectively improved, and the use of single fillers is difficult to realize the collaborative optimization of multiple performances. The base material is made of single material, so that the stability of the whole structure is poor, and the cracking and layering problems are easy to occur after the heat and cold circulation. Meanwhile, the existing production process is rough in control, lacks of accurate filler dispersion and sectional curing processes, is low in coating and curing parameter matching degree, is poor in product performance consistency, is imperfect in post-treatment process, is easy to absorb moisture and deteriorate in the product storage process, and is insufficient in corrosion resistance and weather resistance. In addition, the improvement of the prior art is concentrated on the local adjustment of a single module, the cooperative design among all components is not realized, the problem that the comprehensive performance short plate is difficult to adapt to the multiple performance requirements of fire resistance, insulation, mechanics and the like of the high-voltage cable can be solved. Disclosure of Invention The invention aims at providing a mica tape special for a fire-resistant cable and a forming process thereof. The invention further aims to provide a mica tape special for a fire-resistant cable, which consists of, by mass, 65-80 parts of synthetic mica powder, 12-22 parts of a composite bonding system, a zinc 2-ethylhexanoate curing agent accounting for 8% of the total mass of the composite bonding system, 22 grams per square meter of alkali-free glass fiber cloth reinforcing base material with the thickness of 0.028 mm, and 5-6 parts of an epoxy modified resin composition surface adhesive layer, wherein the composite bonding system is formed by compounding organic silicon resin and epoxy modified resin, the mass ratio of the organic silicon resin to the epoxy modified resin is 1:1-3:1, the synthetic mica powder is the synthetic mica powder prepared by 12000 Gaussian magnetic field magnetic separation iron removal, hydraulic classification, 0.8 megapascal hot pressing stripping at 300 ℃ and wet manufacturing, the sheet diameter D50 of the synthetic mica powder is 35-45 micrometers, and the solid content of the epoxy modified resin composition is 10-12%. Preferably, the modified nano-silica filler further comprises 3 parts of nano-silica filler surface-modified by diphenylmethane diisocyanate, the addition amount of the modifier diphenylmethane diisocyanate is 0.15 part, and the particle size of the nano-silica filler is 20 nanometers. Preferably, the reinforced substrate is replaced by a composite substrate with the total thickness of 0.03mm, the composite substrate is formed by hot-pressing and compounding alkali-free glass fiber cloth with the thickness of 0.028 mm and polyimide film with the thickness of 0.002 mm, the reinforced substrate further comprises 6-8 parts of micro boron nitride-nano graphene composite functional filler with the surface modified by diphenylmethane diisocyanate, the adding amount of the modifier diphenylmethane diisocyanate is 0.3-0.4 part, the particle size of the micro boron nitride is 1 micrometer, and the thickness of the nano graphene is 0.8 nanometer. Preferably, in the micro boron nitride-nano graphene