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CN-121991625-A - Multifunctional polyurethane cable pouring sealant and preparation method thereof

CN121991625ACN 121991625 ACN121991625 ACN 121991625ACN-121991625-A

Abstract

The invention relates to a multifunctional polyurethane cable pouring sealant and a preparation method thereof, and belongs to the technical field of polyurethane materials. The invention combines various metal nitrides with large, medium and small particle diameters as heat conducting fillers, utilizes fluorine-containing silane coupling agent to carry out chemical grafting modification, builds main heat conducting framework by using the large particle diameter fillers, fills large particle gaps by using the medium particle diameter fillers, further compacts a network by using the small particle diameter fillers to form an efficient three-dimensional multistage heat conducting passage, realizes breakthrough promotion of heat conducting performance, combines various performances of flame retardance, water resistance and insulation by carrying out chemical bonding and interface design on functional components and a matrix by using the fluorine-containing silane coupling agent, integrally realizes unification of original contradictory characteristics of high heat conductivity, high flame retardance, strong water resistance, high insulation and the like, and provides an ideal potting protection material for high-performance cable joints, especially for electric power equipment running in humid, high heat or environment requiring high reliability.

Inventors

  • HAN ZHUOZHAN
  • LI HANRU
  • HUANG JIASHENG
  • QU FENGRUI
  • LI MENG
  • LU RUNGE
  • XU YAN
  • WANG ZHIGUO

Assignees

  • 广东电网有限责任公司广州供电局

Dates

Publication Date
20260508
Application Date
20260228

Claims (10)

  1. 1. The multifunctional polyurethane cable pouring sealant is characterized by being obtained by mixing and curing a component A and a component B, wherein the mass ratio of the component A to the component B is (2-3.5): 1; The component A comprises, by mass, 50-90 parts of polyether polyol, 10-20 parts of a heat conducting filler, 4-8 parts of a fluorine-containing silane coupling agent and 0.5-1 part of a defoaming agent, wherein the heat conducting filler is a mixture of three metal nitrides with large particle size, medium particle size and small particle size or a mixture of three or more metal nitrides with the same particle size, the particle size range of the large particle size is 25-35 mu m, the particle size range of the medium particle size is 10-20 mu m, and the particle size range of the small particle size is 1-9 mu m; the component B comprises, by mass, 80-120 parts of polyisocyanate, 0.9-1.4 parts of defoamer, 0.05-0.3 parts of catalyst and 30-50 parts of phosphorus-nitrogen intumescent flame retardant.
  2. 2. The polyurethane cable potting adhesive of claim 1, wherein the polyether polyol is at least one of polyoxypropylene diol or polyoxypropylene triol; And/or the heat conducting filler is a mixture of metal nitrides with three particle sizes of large particle size, medium particle size and small particle size.
  3. 3. The polyurethane cable casting glue according to claim 2, wherein the molecular weight of the polyoxypropylene diol is 1000-2000 Da; and/or the molecular weight of the polyoxypropylene triol is 3000-5000 Da.
  4. 4. The polyurethane cable pouring sealant of claim 1, wherein the metal nitride is at least one of aluminum nitride, gallium nitride, and titanium nitride in the mixture of the three particle sizes of metal nitrides; And/or, in the mixture of three or more metal nitrides with the same particle size, the metal nitrides are three of aluminum nitride, gallium nitride and titanium nitride.
  5. 5. The polyurethane cable potting adhesive of claim 1, wherein the fluorine-containing silane coupling agent is at least one of (3, 3-trifluoropropyl) methyldimethoxysilane or tridecafluorooctyltriethoxysilane; And/or the catalyst is at least one of dibutyl tin dilaurate, stannous octoate or bismuth iso-octoate.
  6. 6. The polyurethane cable potting adhesive of claim 1, wherein the polyisocyanate is at least one of diphenylmethane diisocyanate and isophorone diisocyanate; And/or the defoamer is at least one of YRXP-07B or BYK-a 530.
  7. 7. The polyurethane cable potting adhesive of claim 1, wherein the phosphorus-nitrogen intumescent flame retardant is at least one of ammonium polyphosphate, melamine polyphosphate.
  8. 8. The preparation method of the multifunctional polyurethane cable pouring sealant according to any one of claims 1 to 7, which is characterized by comprising the following steps: S1, vacuum dehydrating polyether polyol, adding a heat conducting filler, a fluorine-containing silane coupling agent and a defoaming agent, uniformly mixing, and then placing the mixture in a protective gas for full reaction to obtain a component A; s2, uniformly mixing polyisocyanate, a defoaming agent, a catalyst and a phosphorus-nitrogen intumescent flame retardant at room temperature to obtain a component B; And S3, mixing the component A obtained in the step S1 with the component B obtained in the step S2, stirring and uniformly mixing, vacuum defoaming, and curing the defoamed mixture in a mold to obtain the multifunctional polyurethane cable pouring sealant.
  9. 9. The preparation method according to claim 8, wherein in the step S1, the vacuum dehydration is performed for 2 to 3 hours at 110 to 120 ℃; And/or, in step S1, the vacuum dehydration is dehydration to a water content of less than 0.02%; and/or in the step S1, the polyether polyol is dehydrated in vacuum and then cooled to 50-60 ℃ and then the heat conducting filler is added; And/or in the step S1, the sufficient reaction condition is 60-80 ℃ and 300-500 rpm for 2-3 hours.
  10. 10. The preparation method of claim 8, wherein in the step S3, the stirring and mixing conditions are 100-200 rpm for 5-10 minutes; and/or, in the step S3, the time for vacuum defoaming is 5-10 minutes; And/or in the step S3, the curing condition is that the temperature is 40-60 ℃ and the curing time is 24-48 hours.

Description

Multifunctional polyurethane cable pouring sealant and preparation method thereof Technical Field The invention relates to the technical field of polyurethane materials, in particular to a multifunctional polyurethane cable pouring sealant and a preparation method thereof. Background The pouring sealant is an important material for packaging and protecting electronic components, has wide application in the field of sealing and protecting cable joints, and has the advantages of directly influencing the structural stability, the insulating property and the long-term operation reliability of the cable joints. The main flow polyurethane pouring sealant has obvious defects on a plurality of key performances, such as poor heat conduction performance, the heat conduction coefficient is generally not more than 0.2W/(m.K), the heat generated by resistance effect and medium polarization in the operation process of the high-voltage cable is difficult to effectively dissipate, the temperature of a joint area is continuously increased, the ageing of materials is accelerated, and the actual power transmission capacity of the cable is weakened. In addition, the flame retardance of the common polyurethane pouring sealant system is still to be improved. Meanwhile, the cable material is inflammable under the open flame condition and the flame expansion is faster, and the cable connector is deployed in underground or humid environment, so that the pouring sealant also needs to have good waterproof capability, and the electrical performance reduction and the insulation structure damage caused by moisture invasion are avoided. In the prior art, functional fillers are introduced by adopting a mechanical simple blending mode, so that the synergistic optimization of multiple indexes such as heat conduction, flame retardance, water resistance, electric insulation and the like is difficult to realize, and the problems of poor component dispersion, weak interface combination, unbalanced comprehensive performance and the like often occur. In view of the current situation, the development of the multifunctional pouring sealant with the characteristics of heat conduction, fire resistance, water resistance, insulation and the like is important to improving the operation reliability and the service life of the cable joint. Disclosure of Invention The invention aims to overcome the defects of the prior art and provide a polyurethane cable pouring sealant with heat conduction, fire resistance, water resistance and insulation functions and a preparation method thereof. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the invention provides a multifunctional polyurethane cable pouring sealant, which is obtained by mixing and curing a component A and a component B, wherein the mass ratio of the component A to the component B is (2-3.5): 1; The component A comprises, by mass, 50-90 parts of polyether polyol, 10-20 parts of a heat conducting filler, 4-8 parts of a fluorine-containing silane coupling agent and 0.5-1 part of a defoaming agent, wherein the heat conducting filler is a mixture of three metal nitrides with large particle size, medium particle size and small particle size or a mixture of three or more metal nitrides with the same particle size, the particle size range of the large particle size is 25-35 mu m, the particle size range of the medium particle size is 10-20 mu m, and the particle size range of the small particle size is 1-9 mu m; the component B comprises, by mass, 80-120 parts of polyisocyanate, 0.9-1.4 parts of defoamer, 0.05-0.3 parts of catalyst and 30-50 parts of phosphorus-nitrogen intumescent flame retardant. The invention utilizes the fluorine-containing silane coupling agent to graft the fluorine-containing group and the metal nitride heat-conducting filler in the polymerization process of the polyurethane material, so that the polyurethane pouring sealant has the waterproof and heat-conducting performances, and the phosphorus-nitrogen expansion type flame retardant is added into the modified polymer matrix, so that the pouring sealant can quickly generate an expansion carbon layer when meeting fire, thereby realizing the fireproof requirement and obtaining the polyurethane cable pouring sealant with heat conduction, fireproof, waterproof and insulating functions. The invention realizes the performance improvement, and the core mechanism is that the in-situ chemical grafting and the interface construction of the metal nitride filler are completed in the polyurethane polymerization process through the fluorine-containing silane coupling agent, rather than the simple physical blending. Specifically, in the component a, the fluorine-containing silane coupling agent is hydrolyzed to generate active silanol, and then the active silanol and hydroxyl groups on the surface of the metal nitride heat-conducting filler undergo dehydration condensation reaction to form firm Si