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CN-121973369-A - High-heat-conductivity environment-friendly modified polyurethane release agent and preparation method thereof

CN121973369ACN 121973369 ACN121973369 ACN 121973369ACN-121973369-A

Abstract

The invention relates to the technical field of release agents, in particular to a high-heat-conductivity environment-friendly modified polyurethane release agent and a preparation method thereof, wherein epoxy modified quaternary ammonium salt aqueous polyurethane emulsion is used as a main component, a ternary composite heat-conducting filler, an environment-friendly silane coupling agent, a VOC-free polyurethane thickener, a plant-based antifoaming agent, an environment-friendly anti-migration agent and deionized water are matched for the balance, and the components are synergistic, so that the high-heat-conductivity environment-friendly modified polyurethane release agent is compatible with high-heat-conductivity, excellent release performance and stability, and is suitable for forming various high-end polyurethane products. The invention has the advantages of environmental protection, no harm, no traditional solvent component, construction of a high-efficiency heat conduction network, avoidance of product quality problem, uniform film formation, smooth demoulding, no residue, prolonged service life of the die, good dispersibility and stability, temperature resistance, acid and alkali resistance and wide application range.

Inventors

  • SHI SHAOQING
  • XIE LIBO
  • MIAO JIE

Assignees

  • 余姚市远东化工有限公司

Dates

Publication Date
20260505
Application Date
20260120

Claims (10)

  1. 1. The high-heat-conductivity environment-friendly modified polyurethane release agent is characterized by comprising, by mass, 38-42% of epoxy modified quaternary ammonium salt aqueous polyurethane emulsion, 8-12% of ternary composite heat-conducting filler, 1.8-2.2% of environment-friendly silane coupling agent, 1.2-1.8% of VOC-free polyurethane thickener, 0.3-0.5% of plant-based defoamer, 0.5-1% of environment-friendly migration inhibitor and 100% of deionized water.
  2. 2. The high-heat-conductivity environment-friendly modified polyurethane release agent according to claim 1, wherein the epoxy modified quaternary ammonium salt aqueous polyurethane emulsion is prepared by gradually polymerizing isophorone diisocyanate, polybutylene adipate glycol, N-methyl diethanolamine and epichlorohydrin, and has a solid content of 45-48% and an epoxy value of 0.05-0.08eq/100g, a number average molecular weight of 20000-30000 and a molecular weight distribution index of 1.2-1.5.
  3. 3. The high-heat-conductivity environment-friendly modified polyurethane release agent according to claim 1, wherein the ternary composite heat-conducting filler is formed by compounding nanocrystalline aluminum nitride, silane modified boron nitride/graphene composite and nano silicon carbide according to a mass ratio of 1:2:0.5, wherein the grain size of the nanocrystalline aluminum nitride is 60-80nm, the mass ratio of boron nitride to graphene in the silane modified boron nitride/graphene composite is 2:1, the grain size of the silane modified boron nitride/graphene composite is 30-50nm, the KH-570 grafting rate of the silane modified boron nitride/graphene composite is 8-12%, and the specific surface area is more than or equal to 50m 2 /g.
  4. 4. The high-heat-conductivity environment-friendly modified polyurethane release agent according to claim 1, wherein the environment-friendly anti-migration agent is polylactic acid grafted polyethylene glycol copolymer, the number average molecular weight is 5000-8000, the glass transition temperature is 55-65 ℃, and the thermal decomposition temperature is more than or equal to 300 ℃.
  5. 5. The high-heat-conductivity environment-friendly modified polyurethane release agent according to claim 3, wherein the heat conductivity of nano silicon carbide is 120-150W/(m.K), the resistivity is more than or equal to 10 16 Ω.cm, the water contact angle after being subjected to surface modification by gamma-aminopropyl triethoxysilane is less than or equal to 30 degrees, the oil absorption value is less than or equal to 20mL/100g, and the dispersion stability is more than or equal to 96 hours.
  6. 6. The high-heat-conductivity environment-friendly modified polyurethane release agent according to claim 1, wherein the VOC-free polyurethane thickener is a VOC-free nonionic associative polyurethane thickener, and the plant-based defoamer is a polyether modified tea saponin defoamer.
  7. 7. A method for preparing the high-thermal-conductivity environment-friendly modified polyurethane release agent as claimed in any one of claims 1 to 6, which is characterized by comprising the following steps: S1, preprocessing ternary composite heat-conducting filler, namely mixing nanocrystalline aluminum nitride, silane modified boron nitride/graphene composite and nano silicon carbide in proportion, performing plasma treatment under argon atmosphere for 10-15min, wherein the plasma power is 800-1000W, adding deionized water to prepare suspension with the mass fraction of 12-14%, performing ultrasonic dispersion for 25-35min with the power of 350-450W, adding environment-friendly silane coupling agent, and stirring and reacting for 1.2-1.8h at the speed of 350-450r/min at 62-68 ℃ to obtain modified heat-conducting filler dispersion; S2, preparing epoxy modified quaternary ammonium salt aqueous polyurethane emulsion, namely vacuum dehydrating polybutylene adipate glycol at 100-110 ℃ for 2-3 hours, cooling to 60-65 ℃, adding isophorone diisocyanate, reacting at 75-80 ℃ for 2-2.5 hours, adding N-methyldiethanolamine for 1-1.5 hours, cooling to 40-45 ℃, adding epichlorohydrin, reacting at 50-55 ℃ for 1.5-2 hours, neutralizing to pH 7.0-7.5 by triethanolamine, and adding water for emulsification to obtain emulsion; S3, composite modification, namely adding the emulsion prepared in the step S2 into a reaction kettle, stirring for 35-40min at a rotating speed of 850-950r/min under the condition of 58-62 ℃, regulating the pH value to 7.8-8.2, dropwise adding the dispersion liquid obtained in the step S1 at a speed of 5-8mL/min, heating to 70-80 ℃ after the dropwise adding, and shearing and dispersing for 45-55min at a rotating speed of 1400-1600r/min at a high speed, wherein the particle size is detected by a laser particle sizer every 15min during the process, so that D90 is less than or equal to 1.5 mu m; S4, adding and curing the auxiliary agent, namely sequentially adding the VOC-free nonionic association polyurethane thickener, the polyether modified tea saponin defoamer and the environment-friendly anti-migration agent, stirring at the rotating speed of 600-700r/min for 18-22min at the temperature of 62-68 ℃, cooling to 25-30 ℃, curing for 20-22h, stirring at the rotating speed of 250-300r/min for 10min every 6h, and filtering by a filter cloth with 250-280 meshes to obtain the release agent.
  8. 8. The preparation method of the high-heat-conductivity environment-friendly modified polyurethane release agent according to claim 7, wherein in the step S2, the molar ratio of isophorone diisocyanate to polybutylene adipate glycol is 1.8:1-2.2:1, the addition amount of N-methyl diethanolamine is 8-12% of the mass of polybutylene adipate glycol, the addition amount of epoxy chloropropane is 5-8% of the total mass of a reaction system, and the stirring rotation speed during emulsification is 1200-1500r/min and the emulsification time is 20-30min.
  9. 9. The preparation method of the high-heat-conductivity environment-friendly modified polyurethane release agent according to claim 7, wherein in the step S3, a gradient heating strategy is adopted during high-speed shearing and dispersing, the temperature is raised to 5 ℃ to a target temperature every 10min, the temperature fluctuation of a system is kept to be less than or equal to +/-2 ℃ through a constant-temperature jacket during dripping, and the stirring speed is 800r/min after the high-speed shearing is finished after the stirring is carried out for 30 min.
  10. 10. The preparation method of the high-heat-conductivity environment-friendly modified polyurethane release agent is characterized in that in the step S4, the curing environment is clean dust-free space, the humidity is controlled to be 40-60%, the particle size distribution span of the filtered release agent is required to be detected to be less than or equal to 1.2 through a laser particle size analyzer, the heat conductivity coefficient is detected to be more than or equal to 1.5W/(m.K), the release agent can be packaged after being qualified, and the sealing storage temperature of a packaging container is 5-35 ℃ when the release agent is sealed by a light-resistant polyethylene barrel.

Description

High-heat-conductivity environment-friendly modified polyurethane release agent and preparation method thereof Technical Field The invention relates to the technical field of release agents, in particular to a high-heat-conductivity environment-friendly modified polyurethane release agent and a preparation method thereof. Background Polyurethane materials are widely applied to the fields of buildings, automobiles, electronics, furniture and the like due to excellent mechanical properties, heat preservation and insulation properties and molding adaptability, and the release agent is used as a key auxiliary agent in the molding process of polyurethane products, and the performance of the release agent directly influences the surface quality of the products, the molding efficiency and the service life of molds. The traditional polyurethane release agent is mainly divided into solvent type release agent, oily release agent and aqueous release agent, wherein the solvent type release agent has excellent release effect, but has high VOC (volatile organic compound) emission, so that the environment is polluted, the health of operators is endangered, the current environmental protection regulations and the green production concept are not met, the problems of more residues, easy product surface pollution, reduced subsequent coating adhesive force and the like of the oily release agent exist, and the application of the oily release agent in high-end products is limited. The aqueous polyurethane release agent is the main development flow because of the advantages of environmental protection, safety and the like, but the existing aqueous product has the defect of insufficient heat conduction performance. In the polyurethane product forming process, the reaction heat release is difficult to be rapidly diffused, the temperature inside the product is easy to be uneven, the quality problems of shrinkage cavity, deformation, internal stress concentration and the like occur, and the forming influence on large-sized and complex-structure products is more obvious. In order to improve the heat conductivity, the prior art adopts single heat conducting filler such as aluminum nitride, boron nitride and the like for modification, but the single filler has the problems of poor dispersibility and insufficient compatibility with a polyurethane matrix, is easy to agglomerate, cannot effectively construct a heat conducting network, and can damage the film forming continuity of a release agent, so that the release force is increased and the mold residue is increased. Meanwhile, the existing aqueous release agent has the problem of single functionality, and is difficult to achieve the environmental protection, high thermal conductivity, excellent release performance and long-term stability. In addition, the existing release agent has insufficient migration resistance, the filler is easy to be chromatographed from a film after long-term use, the repeated use times of the release agent are reduced, the surface of a product is possibly polluted, and the subsequent treatment cost is increased. Therefore, the development of the modified polyurethane release agent with high heat conductivity, environmental protection, excellent release performance and stability becomes a key for solving the pain point of the current industry, and has important significance for promoting the development of polyurethane product industry to high efficiency, green and high-end. Disclosure of Invention (One) solving the technical problems Aiming at the defects of the prior art, the invention provides a high-heat-conductivity environment-friendly modified polyurethane release agent and a preparation method thereof. (II) technical scheme The high heat conduction environment-friendly modified polyurethane release agent comprises, by mass, 38-42% of epoxy modified quaternary ammonium salt aqueous polyurethane emulsion, 8-12% of ternary composite heat conducting filler, 1.8-2.2% of environment-friendly silane coupling agent, 1.2-1.8% of VOC-free polyurethane thickener, 0.3-0.5% of plant-based defoamer, 0.5-1% of environment-friendly anti-migration agent and 100% of deionized water. Preferably, the epoxy modified quaternary ammonium salt aqueous polyurethane emulsion is prepared by gradually polymerizing isophorone diisocyanate, polybutylene adipate glycol, N-methyl diethanol amine and epichlorohydrin, wherein the epoxy value of the epoxy modified quaternary ammonium salt aqueous polyurethane emulsion with the solid content of 45-48% is 0.05-0.08eq/100g, the number average molecular weight is 20000-30000, and the molecular weight distribution index is 1.2-1.5. Preferably, the ternary composite heat-conducting filler is formed by compounding nanocrystalline aluminum nitride, silane modified boron nitride/graphene composite and nano silicon carbide according to the mass ratio of 1:2:0.5, wherein the grain size of the nanocrystalline aluminum nitride is 60-80nm, the mass ra