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CN-121975152-A - High-solid-content self-emulsifying epoxy resin composition, preparation method and application thereof

CN121975152ACN 121975152 ACN121975152 ACN 121975152ACN-121975152-A

Abstract

The invention provides a high-solid content self-emulsifying epoxy resin composition and a preparation method thereof, wherein the method comprises the steps of preparing monoethanolamine modified bisphenol A type epoxy resin; preparing a branched structure emulsifier, and preparing a high-solid self-emulsifying epoxy resin composition from the fourth bisphenol A type epoxy resin, the monoethanolamine modified bisphenol A type epoxy resin, the branched structure emulsifier, the cardanol emulsifier and the solvent. The prepared composition has excellent self-emulsifying capacity and good wettability to zinc powder, can effectively reduce the hydrogen production risk during storage, and endows a system with excellent thermal storage stability, and the aqueous epoxy zinc-rich primer prepared from the composition has high drying speed, strong adhesive force and excellent impact resistance and salt spray resistance (> 1000 h).

Inventors

  • YU LE
  • ZHOU QIJUN
  • WANG DONGDONG

Assignees

  • 江西安德力高新科技有限公司

Dates

Publication Date
20260505
Application Date
20251224

Claims (10)

  1. 1. The preparation method of the high-solid self-emulsifying epoxy resin composition is characterized by comprising the following steps of: adding a first bisphenol A epoxy resin into a reaction kettle, dropwise adding monoethanolamine into the reaction kettle under a stirring condition, controlling the reaction kettle at a first preset temperature, and after the dropwise adding is finished, performing a first reaction on the first bisphenol A epoxy resin and the monoethanolamine in the reaction kettle at a second preset temperature to obtain monoethanolamine modified bisphenol A epoxy resin; Mixing first polyether amine and second bisphenol A epoxy resin to perform a second reaction at a third preset temperature and perform a third reaction at a fourth preset temperature to obtain a first-stage reactant, adding second polyether amine into the first-stage reactant to perform a fourth reaction at a fifth preset temperature and obtain a second-stage reactant, cooling the second-stage reactant to a sixth preset temperature, adding third bisphenol A epoxy resin into the second-stage reactant to perform a fifth reaction at a seventh preset temperature and performing a sixth reaction at an eighth preset temperature to obtain a branched structure emulsifier; and sequentially adding the fourth bisphenol A type epoxy resin, the monoethanolamine modified bisphenol A type epoxy resin, the branched structure emulsifier, the cardanol emulsifier and the solvent into a dispersing cylinder, heating the dispersing cylinder to an eighth preset temperature, and stirring to obtain the high-solid-content self-emulsifying epoxy resin composition.
  2. 2. The method for preparing the high-solid-content self-emulsifying epoxy resin composition according to claim 1, wherein the weight part of the fourth bisphenol A type epoxy resin is 50-65 parts, the weight part of the monoethanolamine modified bisphenol A type epoxy resin is 8-12 parts, the weight part of the branched structure emulsifier is 4-8 parts, the weight part of the cardanol emulsifier is 2-5 parts, and the weight part of the solvent is 20-30 parts.
  3. 3. The method for preparing a high-solid self-emulsifying epoxy resin composition according to claim 1, wherein the molar ratio of the first bisphenol A type epoxy resin to the monoethanolamine is (2-3): 1.
  4. 4. The method for preparing the high-solid-content self-emulsifying epoxy resin composition according to claim 1, wherein the molar ratio of the first polyether amine to the second bisphenol A epoxy resin is (0.8-1.5): (2.1-3.5), the mass ratio of the second polyether amine to the first polyether amine is 2:1, and the mass ratio of the third bisphenol A epoxy resin to the second bisphenol A epoxy resin is 1:1.
  5. 5. The method for preparing the high-solid-content self-emulsifying epoxy resin composition according to claim 1, wherein the first preset temperature is not higher than 65 ℃, the dripping speed of monoethanolamine is 0.5 drops/second, the dripping time of monoethanolamine is 30min, the second preset temperature is 80-105 ℃, and the time of the first reaction is 3-4 h.
  6. 6. The method for preparing the high-solid-content self-emulsifying epoxy resin composition according to claim 1, wherein the third preset temperature is 75-90 ℃, the second reaction time is 2-3 hours, the fourth preset temperature is 95-110 ℃, the third reaction time is 4-5 hours, the fifth preset temperature is 90-100 ℃, the fourth reaction time is 4 hours, the sixth preset temperature is 70 ℃, the seventh preset temperature is 105-110 ℃, the fifth reaction time is 1 hour, the eighth preset temperature is 120-125 ℃, and the sixth reaction time is 3 hours.
  7. 7. The method for preparing a high-solid content self-emulsifying epoxy resin composition according to claim 1, wherein the mass ratio of the second polyetheramine to the first polyetheramine is 2:1, and the mass ratio of the third bisphenol a epoxy resin to the second bisphenol a epoxy resin is 1:1.
  8. 8. The method for preparing a high-solid self-emulsifying epoxy resin composition according to claim 1, wherein the eighth preset temperature is 70 ℃ to 90 ℃, and the stirring speed is 500rpm to 1000rpm.
  9. 9. The high-solid self-emulsifying epoxy resin composition, which is characterized in that the high-solid self-emulsifying epoxy resin composition is prepared according to the preparation method of the high-solid self-emulsifying epoxy resin composition according to any one of claims 1-8.
  10. 10. The use of the high solids content self emulsifying epoxy resin composition of claim 9 in the preparation of an aqueous two component zinc rich primer.

Description

High-solid-content self-emulsifying epoxy resin composition, preparation method and application thereof Technical Field The invention relates to the technical field of water-based heavy-duty coating, in particular to a high-solid-content self-emulsifying epoxy resin composition, a preparation method and application thereof. Background Corrosion of metallic materials in natural environments, particularly in marine high-salt, high-humidity, oxygen-rich environments, is a key factor leading to significant infrastructure failures and economic losses in ports, ships, offshore platforms, and the like. Among various protection means, zinc-rich primer with physical shielding and cathodic protection functions is widely used. Among them, the epoxy resin becomes a core matrix resin of the zinc-rich primer by virtue of its excellent adhesion, chemical stability and mechanical strength. With the stringent environmental regulations, the development of high performance aqueous epoxy zinc-rich systems is becoming an urgent need. The waterborne epoxy resin has two paths, namely an external emulsifier method (physical method) and a self-emulsifying method (chemical method). Although the process of the method of adding the emulsifier is simple, the residual small molecular emulsifier can seriously deteriorate the corrosion resistance and adhesive force of a paint film, and organic solvents are often added for adjusting the construction viscosity, so that VOC is increased, and the requirement of high performance is difficult to meet. In contrast, the self-emulsifying method, by chemically bonding hydrophilic groups to the resin skeleton, provides itself with water-dispersing ability, and can substantially reduce the use of harmful auxiliaries, is a decisive technique for obtaining a high-performance aqueous coating. However, the application of self-emulsifying resin to zinc-rich systems has multiple challenges, namely that the latent heat of evaporation of water is high, so that a paint film is slowly dried, the construction efficiency is affected, the conventional aqueous emulsion contains free water, gas production and tank expansion can be caused after the conventional aqueous emulsion is mixed with high-activity zinc powder, the storage safety is poor, and the zinc powder is difficult to stably disperse for a long time without sedimentation under the condition of high solid content. Disclosure of Invention Aiming at the defects of the prior art, the invention aims to provide a high-solid-content self-emulsifying epoxy resin composition, a preparation method and application thereof, and aims to solve the technical problems that when the self-emulsifying resin is applied to a zinc-rich system in the prior art, firstly, the evaporation latent heat of water is high, a paint film is slow to dry, the construction efficiency is affected, secondly, the conventional aqueous emulsion contains free water, gas production and tank expansion can be caused after the conventional aqueous emulsion is mixed with high-activity zinc powder, the storage safety is poor, and thirdly, the zinc powder is difficult to be stably dispersed for a long time under the high-solid-content condition and does not settle. In order to achieve the above object, in a first aspect, the present invention provides a method for preparing a high-solid content self-emulsifying epoxy resin composition, comprising the steps of: adding a first bisphenol A epoxy resin into a reaction kettle, dropwise adding monoethanolamine into the reaction kettle under a stirring condition, controlling the reaction kettle at a first preset temperature, and after the dropwise adding is finished, performing a first reaction on the first bisphenol A epoxy resin and the monoethanolamine in the reaction kettle at a second preset temperature to obtain monoethanolamine modified bisphenol A epoxy resin; Mixing first polyether amine and second bisphenol A epoxy resin to perform a second reaction at a third preset temperature and perform a third reaction at a fourth preset temperature to obtain a first-stage reactant, adding second polyether amine into the first-stage reactant to perform a fourth reaction at a fifth preset temperature and obtain a second-stage reactant, cooling the second-stage reactant to a sixth preset temperature, adding third bisphenol A epoxy resin into the second-stage reactant to perform a fifth reaction at a seventh preset temperature and performing a sixth reaction at an eighth preset temperature to obtain a branched structure emulsifier; and sequentially adding the fourth bisphenol A type epoxy resin, the monoethanolamine modified bisphenol A type epoxy resin, the branched structure emulsifier, the cardanol emulsifier and the solvent into a dispersing cylinder, heating the dispersing cylinder to an eighth preset temperature, and stirring to obtain the high-solid-content self-emulsifying epoxy resin composition. Further, the weight part of the fourth bisphenol A type ep