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CN-121991629-A - High-heat-conductivity insulating pouring sealant material and preparation method thereof

CN121991629ACN 121991629 ACN121991629 ACN 121991629ACN-121991629-A

Abstract

The invention discloses a high heat conduction insulating pouring sealant material and a preparation method thereof, comprising the steps of carrying out prepolymerization reaction on an elastic polymer containing hydroxyl, a liquid aryl diisocyanate prepolymer, modified epoxy-acrylic resin and a catalyst in inert atmosphere to obtain a precursor mixture, and sequentially carrying out silane coupling treatment and boron nitride coating treatment on multi-particle-size spherical alumina to obtain surface functionalized composite powder; the preparation method comprises the steps of mixing a reactive diluent, a plasticizer, a dispersing agent and a defoaming agent, adding composite powder, shearing, dispersing and defoaming to obtain thixotropic filler slurry with high solid content, mixing a precursor mixture and the filler slurry with high solid content according to a preset proportion to obtain pouring sealant slurry, injecting the pouring sealant slurry into a mold, constructing a heat conduction passage, and solidifying and shaping to obtain the pouring sealant material with high heat conductivity, good electrical insulation and stability.

Inventors

  • LIU QINGMIN
  • LIN YUAN
  • ZENG WENTAO

Assignees

  • 迈高精细高新材料(宜昌)有限公司
  • 迈高精细高新材料（深圳）有限公司

Dates

Publication Date
20260508
Application Date
20260225

Claims (10)

  1. 1. The preparation method of the high-heat-conductivity insulating pouring sealant material is characterized by comprising the following steps of: s1, carrying out prepolymerization reaction on an elastic polymer containing hydroxyl, a liquid aryl diisocyanate prepolymer, a modified epoxy-acrylic resin and a catalyst in inert atmosphere to obtain a precursor mixture, and sequentially carrying out silane coupling treatment and boron nitride coating treatment on multi-particle-size spherical alumina to obtain surface functionalized composite powder; S2, mixing a reactive diluent, a plasticizer, a dispersing agent and a defoaming agent, adding the composite powder, and carrying out shearing dispersion and defoaming treatment to obtain thixotropic filler slurry with high solid content; And S3, mixing the precursor mixture with the filler slurry with high solid content according to a preset proportion to obtain pouring sealant slurry, injecting the pouring sealant slurry into a mould, densely arranging filler particles in the pouring sealant slurry through controlled centrifugation and temperature control treatment, constructing a heat conduction path, and then irradiating with ultraviolet light to crosslink photocuring sites in the slurry so as to realize primary shaping.
  2. 2. The method for preparing the high-heat-conductivity insulating pouring sealant material according to claim 1, wherein the hydroxyl-containing elastic polymer is hydroxyl-terminated polybutadiene, and the liquid aryl diisocyanate prepolymer is a prepolymer formed by reacting one of toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate with polyalcohol.
  3. 3. The preparation method of the high-heat-conductivity insulating pouring sealant material according to claim 1, wherein the multi-particle-size spherical alumina comprises large-particle-size spherical alumina, medium-particle-size spherical alumina and small-particle-size spherical alumina, and the mass ratio of the large-particle-size spherical alumina, the medium-particle-size spherical alumina to the small-particle-size spherical alumina is (40-48): 15-22): 4-10.
  4. 4. The preparation method of the high-heat-conductivity insulating pouring sealant material is characterized in that the preparation process of the composite powder is as follows: s11, drying the multi-particle-size spherical alumina in vacuum at 100-120 ℃ for 1-2 hours, and then dispersing the multi-particle-size spherical alumina in a neutral buffer solution with the pH value of 7.2-7.8 to form uniform suspension; s12, adding a silane coupling agent containing catechol functional groups into the suspension, wherein the addition amount of the silane coupling agent is 2.0-2.5% of the total mass of the spherical alumina, continuously stirring and reacting for 2-3 hours at 25-35 ℃, filtering, washing and drying after the reaction is finished to obtain intermediate powder of the surface grafted silane; S13, re-dispersing the intermediate powder in an alcohol-water mixed solvent, adding hexagonal boron nitride dispersion liquid with the total mass of 3-8%, treating for 30-60 minutes under the synergistic effect of ultrasound and shearing, then adding a trace crosslinking accelerator, stirring for 1-2 hours at 40-60 ℃ gently, enabling a boron nitride sheet layer to be anchored on the surface of the powder through chemical action, and drying to obtain the surface-functionalized composite powder.
  5. 5. The method for preparing the high-heat-conductivity insulating pouring sealant material according to claim 4, wherein the preparation process of the precursor mixture is as follows: S14, adding an elastic polymer containing hydroxyl into a reactor under the protection of inert atmosphere, heating to 70-78 ℃, dehydrating in vacuum for 30-60 minutes, slowly dripping a liquid state aryl diisocyanate prepolymer, and controlling the NCO value of a reaction system to reach a preset range; S15, adding the modified epoxy-acrylic resin and the catalyst into a reaction system, stirring for 1.5-2.5 hours at a constant temperature of 80-85 ℃, performing prepolymerization and grafting reaction, and cooling to obtain a viscous precursor mixture.
  6. 6. The method for preparing the high-thermal-conductivity insulating pouring sealant material according to claim 1, wherein the step S2 specifically comprises: S21, mixing the reactive diluent, the plasticizer and the dispersing agent at 25-35 ℃, stirring for 10-20 minutes at a rotating speed of 300-500rpm until the system is clear and uniform, then adding the defoaming agent, and continuing stirring for 5 minutes at a low speed to obtain an auxiliary agent premix; S22, adding the surface functionalized composite powder into the auxiliary agent premix liquid in batches and slowly, keeping the rotation speed of 400-600rpm for stirring in the adding process, heating the system to 40-50 ℃ after all the materials are added, and stirring for 15-30 minutes at a constant speed at the temperature to enable the auxiliary agent system to fully infiltrate the surface of the filler; S23, transferring the system with the primary dispersion to high-speed shearing equipment, shearing at a high speed of 1500-2000rpm for 8-15 minutes under the condition of vacuum degree of-0.08 to-0.095 MPa, and then shearing at a medium speed of 800-1200rpm for 5-10 minutes, wherein in the process, low-boiling substances are extracted by vacuum and the state of slurry is observed, so as to obtain the primary mixed slurry with uniform fluidity; S24, placing the primary mixed slurry in a closed container, keeping the primary mixed slurry for 20-40 minutes in a high vacuum environment with the temperature of 50-60 ℃ and the pressure of more than-0.1 MPa, then releasing the vacuum, and standing and curing the primary mixed slurry for 1-2 hours under the protection of inert gas to obtain the filler slurry with stable thixotropic property and high solid content.
  7. 7. The method for preparing the high-thermal-conductivity insulating pouring sealant material according to claim 1, wherein the step S3 specifically comprises: S31, placing the precursor mixture and the high-solid-content filler slurry in a mixing kettle according to the mass ratio of 2.6-2.8:1, stirring for 5-10 minutes at 40-50 ℃ and the rotating speed of 200-400rpm, and then raising the rotating speed to 600-800rpm to continue stirring for 3-5 minutes to obtain uniform pouring sealant slurry with stable viscosity; S32, transferring the pouring sealant slurry to vacuum filling equipment, maintaining the vacuum degree of-0.08 to-0.1 MPa for 5-10 minutes to remove bubbles involved in stirring, and injecting the pouring sealant slurry into a die preheated to 40-50 ℃ or a cavity of a device to be packaged; s33, placing the filled mold in a centrifugal device with programmable temperature control, and performing controlled centrifugation and temperature control treatment to orderly arrange filler particles with different particle diameters and a surface boron nitride thin layer along a heat flow direction and closely contact the filler particles and the surface boron nitride thin layer to construct an insulating heat conduction path; S34, performing ultraviolet irradiation on the slurry system after centrifugal arrangement, firstly, vertically irradiating the slurry system for 60-90 seconds from a main plane of a die by adopting ultraviolet light to realize preliminary crosslinking of a main area, and then adjusting the angle of a light source or adding a lateral auxiliary light source, and performing supplementary irradiation on the side wall of the die or a complex structure area for 20-40 seconds to fully excite and crosslink light curing sites in the slurry to form a primary curing body capable of locking the space position of a filler network; And S35, placing the primary solidified body and the mould in an oven at 60-80 ℃ for 20-40 minutes to obtain a preformed body.
  8. 8. The method for preparing a high thermal conductivity insulating potting adhesive material according to claim 7, wherein the controlled centrifugation and temperature control treatment are carried out under the condition that centrifugation is carried out at a rotation speed of 800-1500rpm for 5-20 minutes at 40-60 ℃.
  9. 9. The method for preparing the high thermal conductivity insulating pouring sealant material according to claim 1, wherein the step S3 further comprises: s4, carrying out step heating heat treatment on the primary cured slurry to fully crosslink thermosetting groups in the precursor, and promoting the functional layer on the surface of the filler to form covalent bonding with the matrix, so as to finally obtain the cured potting.
  10. 10. A high thermal conductivity insulating potting adhesive material, characterized in that the high thermal conductivity insulating potting adhesive material is prepared by the preparation method of the high thermal conductivity insulating potting adhesive material according to any one of claims 1 to 9, and comprises: a matrix polymer formed by reacting a hydroxyl-containing elastomeric polymer, a liquid aryl diisocyanate prepolymer, a modified epoxy-acrylic resin, and a catalyst, totaling 100 parts; A combination of functional fillers dispersed in the matrix polymer, totaling 50 to 100 parts; And 8-14 parts of reactive diluent, 5-8 parts of plasticizer, 0.3-1.0 parts of dispersing agent and 0.02-0.1 part of defoaming agent.

Description

High-heat-conductivity insulating pouring sealant material and preparation method thereof Technical Field The invention relates to the technical field of pouring sealant, in particular to a high-heat-conductivity insulating pouring sealant material and a preparation method thereof. Background In the field of building energy conservation and photovoltaic building integration, a building enclosure structure and a waterproof layer also face the heat dissipation requirement. For example, a solar roof, a photovoltaic roof, a heat dissipation structure in underground engineering, and the like, not only require that a waterproof material has excellent waterproof property, weather resistance and flexibility, but also have certain heat conduction capability so as to accelerate heat dissipation, and avoid accelerated aging of the waterproof layer, structural damage or system efficiency reduction caused by heat accumulation. At present, common building waterproof materials such as elastomer modified asphalt, plastomer modified asphalt, ethylene propylene diene monomer waterproof coiled materials, thermoplastic polyolefin waterproof coiled materials and the like have good waterproof performance and certain flexibility, but the heat conductivity coefficient of the building waterproof materials is generally low, and the building waterproof materials cannot meet the increasingly growing requirements on heat dissipation and energy conservation of buildings. Currently, in order to improve the heat conducting property of polymer-based pouring sealant, the industry generally adopts a technical route of filling heat conducting fillers (such as aluminum oxide, boron nitride and the like) in a high proportion. However, this method has significant drawbacks in that when the filler loading reaches a level sufficient to construct an efficient heat conductive path, the filler particles are extremely prone to form physical contact surfaces in the matrix, which not only increases the viscosity of the system, deteriorates manufacturability, but more importantly, may form conductive or leaky paths, resulting in a decrease in the volume resistivity and dielectric strength of the material, and difficulty in ensuring insulation reliability. Especially under the long-term damp and hot and vibration stress effects, the filler and the matrix can be subjected to interface stripping or relative displacement, so that the risk of deterioration of the electrical performance is further increased. Therefore, the existing high-filling pouring sealant technology is difficult to maintain the long-term stable high insulation characteristic of the material under severe working conditions while ensuring high thermal conductivity, and cannot meet the technical requirements of the high-reliability application scene. Disclosure of Invention The invention aims to provide a high-heat-conductivity insulating pouring sealant material and a preparation method thereof, and solves the technical problems. To achieve the purpose, the invention adopts the following technical scheme: A preparation method of a high-heat-conductivity insulating pouring sealant material comprises the following steps: s1, carrying out prepolymerization reaction on an elastic polymer containing hydroxyl, a liquid aryl diisocyanate prepolymer, a modified epoxy-acrylic resin and a catalyst in inert atmosphere to obtain a precursor mixture, and sequentially carrying out silane coupling treatment and boron nitride coating treatment on multi-particle-size spherical alumina to obtain surface functionalized composite powder; S2, mixing a reactive diluent, a plasticizer, a dispersing agent and a defoaming agent, adding the composite powder, and carrying out shearing dispersion and defoaming treatment to obtain thixotropic filler slurry with high solid content; And S3, mixing the precursor mixture with the filler slurry with high solid content according to a preset proportion to obtain pouring sealant slurry, injecting the pouring sealant slurry into a mould, densely arranging filler particles in the pouring sealant slurry through controlled centrifugation and temperature control treatment, constructing a heat conduction path, and then irradiating with ultraviolet light to crosslink photocuring sites in the slurry so as to realize primary shaping. Optionally, the hydroxyl-containing elastic polymer is hydroxyl-terminated polybutadiene, and the liquid aryl diisocyanate prepolymer is a prepolymer formed by reacting one of toluene diisocyanate, diphenylmethane diisocyanate and isophorone diisocyanate with polyol. Optionally, the multi-particle-size spherical alumina comprises spherical alumina with large particle size, medium particle size and small particle size, wherein the mass ratio of the large particle size to the medium particle size to the small particle size is (40-48): 15-22): 4-10. Optionally, the preparation process of the composite powder comprises the following steps: s11, drying the mult