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CN-122011913-A - Composite coating with electromagnetic protection and explosion prevention functions, preparation method and application

CN122011913ACN 122011913 ACN122011913 ACN 122011913ACN-122011913-A

Abstract

The invention belongs to the technical field of electromagnetic wave absorbing materials, and discloses a composite coating with electromagnetic protection and explosion prevention functions, a preparation method and application thereof. The coating comprises 40-60 parts of polycarbodiimide modified diphenylmethane diisocyanate, 40-60 parts of polycarbonate diol with the equivalent weight of 1000, and a semi-prepolymer with the NCO content of 10-20%, 73-100 parts of polyether amine curing agent, 15-20 parts of diethyltoluenediamine or dimethylthiotoluenediamine, 0.5-2 parts of calcium carbonate and 3-6 parts of magnetic powder. The two components are quickly formed by a spraying process. The invention takes the polyurea elastomer as a matrix, endows the coating with excellent impact resistance and explosion resistance, water impermeability, oil resistance, low temperature resistance and other environmental tolerance, and simultaneously realizes the adjustable electromagnetic wave absorption function by doping specific magnetic powder. The coating has simple preparation process and excellent comprehensive performance, and is especially suitable for equipment surfaces with high requirements on stealth and survival protection, such as oil storage equipment.

Inventors

  • Qi Xingze
  • JIN WEN

Assignees

  • 山东大杼新材料有限公司

Dates

Publication Date
20260512
Application Date
20260309

Claims (10)

  1. 1. A composite coating with electromagnetic protection and explosion prevention functions is characterized by comprising 40-60 parts of polycarbodiimide modified diphenylmethane diisocyanate, 40-60 parts of semi-prepolymer synthesized by polycarbonate diol and having NCO content of 10-20%, 73-100 parts of polyether amine curing agent, 15-20 parts of diethyl toluenediamine or dimethyl thiotoluenediamine, 0.5-2 parts of calcium carbonate and 3-6 parts of magnetic powder.
  2. 2. The composite coating of claim 1, wherein the polyether amine curing agent comprises JEFFAMINET-5000 and jeffamine-2000.
  3. 3. The composite coating of claim 2, wherein 73-100 parts of the polyether amine curing agent comprises 8-12 parts JEFFAMINE T-5000 and 65-80 parts JEFFAMINE D-2000.
  4. 4. The composite coating according to claim 1, wherein the magnetic powder is at least one of a flake carbonyl iron powder, a flake sendust powder or a flake sendust powder, and has a particle size of 10-50 μm.
  5. 5. A method for preparing the composite coating with electromagnetic protection and explosion prevention functions according to any one of claims 1 to 4, which comprises the following steps: s1, reacting polycarbodiimide modified diphenylmethane diisocyanate with polycarbonate diol to synthesize isocyanate semi-prepolymer with NCO content of 10% -20%, wherein the isocyanate semi-prepolymer is used as a component A; S2, blending a polyether amine curing agent, an aromatic diamine chain extender, nano calcium carbonate and magnetic powder to obtain an R component; And S3, coating the A component and the R component on the surface of the substrate through a compressed air spraying process, and reacting to form the composite coating.
  6. 6. The preparation method according to claim 5, wherein in the step S3, the volume ratio of the a component to the R component is 0.5-2, and the spraying gel time is 3-10 seconds by adopting a compressed air spraying process.
  7. 7. The preparation method of the compressed air spraying process according to claim 5, wherein parameters of the compressed air spraying process are that a spray gun caliber is 1-2 mm, air pressure is 0.5-1.2 MPa, and spraying distance is 10-100 cm.
  8. 8. The method according to claim 5, wherein in step S3, the substrate surface is subjected to pretreatment of polishing and solvent cleaning before spraying.
  9. 9. Use of a composite coating according to any one of claims 1-4 in a coating oil storage device.
  10. 10. The application of claim 9, wherein the composite coating is sprayed and coated on an oil storage device to achieve broadband effective electromagnetic absorption in the 2-18 ghz band.

Description

Composite coating with electromagnetic protection and explosion prevention functions, preparation method and application Technical Field The invention belongs to the technical field of electromagnetic wave absorbing materials. In particular, the invention relates to a composite coating with electromagnetic protection and explosion prevention functions, a preparation method and application thereof. Background In a complex electromagnetic environment, radar stealth and survival protection capability of equipment are important. The wave-absorbing coating is widely applied as an effective target radar characteristic control means, wherein carbonyl iron powder has high magnetic permeability and higher Curie temperature, and is one of the most widely used magnetic absorbers at present. However, the traditional wave-absorbing coating using thermosetting resin such as epoxy, phenolic aldehyde and polyimide as a matrix has the defects of large brittleness, insufficient toughness, poor shock resistance and the like. When the surface of equipment encounters a fragment impact or explosion impact load, the coating is easy to crack, pulverize and fall off, so that the radar stealth requirement of a target cannot be met. In addition, environmental resistance such as water permeability, wear resistance, impact resistance, low temperature resistance, oil resistance and the like of the wave-absorbing coating are also key indexes for evaluating engineering application values of the wave-absorbing coating. Therefore, developing a multifunctional coating which not only can maintain excellent wave absorbing performance, but also has good explosion-proof characteristics and environmental resistance has become a key way for improving the comprehensive performance of equipment. Polyurea elastomers, which are high performance polymers produced by the rapid reaction of isocyanates with amino compounds, offer great potential as surface protective coatings for equipment by their unique molecular structure and reaction mechanism. In terms of mechanical properties, the coating has excellent explosion-proof and impact-resistant properties due to extremely high elongation at break and energy dissipation capacity. In the aspect of environmental tolerance, the extremely low water permeability of the polyurea material can effectively block water penetration and prevent foaming, falling and oxidation failure of the coating, the excellent low temperature resistance can ensure that the polyurea material still maintains high elasticity in a cold environment to avoid embrittlement cracking, and meanwhile, the excellent oil resistance can resist corrosion of chemical media such as fuel oil and the like, so that the long-term reliability of the coating in an oil stain environment is ensured. In the prior art, a radar wave-absorbing explosion-proof polyurea material which takes ferrite as a main absorbent is used, and the material has good explosion-proof performance and wave-absorbing performance, but the performance of the material in the aspect of environmental tolerance is deficient, so that the radar characteristic control of a target in a complex environment is difficult to meet. The organic-inorganic flame retardant is used for preparing the compound flame-retardant coating material in the prior art, and the compound flame-retardant coating material has high-efficiency flame-retardant property and adhesive force, but has insufficient stealth performance. In the prior art, polyether polyurethane elastomer is used as a matrix to prepare an oil storage bag material with camouflage function, and the coating material has good water resistance, good oil resistance, strong environmental tolerance and visible light/near infrared camouflage function, but lacks the stealth performance of microwave bands. Disclosure of Invention In order to solve the problems in the prior art, the invention provides a composite coating with electromagnetic protection and explosion prevention functions, a preparation method and application thereof. The preparation method is simple and easy to implement, and the prepared coating has excellent explosion-proof performance, electromagnetic protection performance and mechanical performance, can meet the electromagnetic protection requirements of different frequency ranges, and has stronger environmental tolerance, such as wear resistance, impact resistance, water impermeability, oil resistance, low temperature resistance and the like. The invention provides a composite coating with electromagnetic protection and explosion prevention functions, which comprises 40-60 parts of polycarbodiimide modified diphenylmethane diisocyanate, 40-60 parts of semi-prepolymer synthesized by polycarbonate diol and having NCO content of 10-20%, 73-100 parts of polyether amine curing agent, 15-20 parts of diethyl toluenediamine or dimethyl thiotoluenediamine, 0.5-2 parts of calcium carbonate and 3-6 parts of magnetic powder. Optionally, the polye