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CN-122011892-A - Phenolic aldehyde-epoxy anti-corrosion water paint and preparation method thereof

CN122011892ACN 122011892 ACN122011892 ACN 122011892ACN-122011892-A

Abstract

The invention relates to the technical field of anti-corrosion paint, in particular to phenolic-epoxy anti-corrosion water paint and a preparation method thereof. The anticorrosive water paint consists of A, B components, wherein the A component comprises resin emulsion and slurry, the B component comprises a curing agent and an auxiliary agent, and the resin emulsion is prepared by emulsifying and compounding benzoxazine prepolymer, epoxy phosphoric acid prepolymer, bisphenol A type liquid epoxy resin, betaine type zwitterionic emulsifier, dextran-based microgel, phytic acid, 3-glycidoxypropyl trimethoxy silane and the like. The system realizes high compatibility and long-term stability of phenolic aldehyde and epoxy in a water-based system, the obtained coating film is compact, strong in adhesive force, high in mechanical strength, excellent in water resistance, damp heat resistance and salt spray resistance, capable of keeping long-term protection effect in severe environments such as high humidity, high salt, temperature circulation and the like, and suitable for application of metal anti-corrosion coatings in the fields of ships, aviation, high iron, ocean engineering and the like.

Inventors

  • WANG CHAO
  • JIA YAN

Assignees

  • 江苏永义新材料技术有限责任公司

Dates

Publication Date
20260512
Application Date
20260331

Claims (10)

  1. 1. The phenolic-epoxy anticorrosive water-based paint is characterized by being prepared by mixing and curing A, B components according to the mass ratio of 100:28-32; The component A comprises the following raw materials, by weight, 360-400 parts of slurry and 600-640 parts of resin emulsion; The component B comprises the following raw materials, by weight, 260-300 parts of a curing agent, 200-240 parts of deionized water and 1.5-2.5 parts of a defoaming agent; The preparation steps of the resin emulsion are as follows: S1, preparing a benzoxazine prepolymer, namely, in anhydrous 1,4 dioxane, taking phenol, para-aminobenzoic acid and formaldehyde solution as reaction raw materials, and performing condensation-ring closure reaction at 80-90 ℃ to generate the benzoxazine prepolymer; S2, preparing a zwitterionic emulsifier, namely performing epoxy ring-opening reaction on polyethylene glycol diglycidyl ether and 3- (dimethylamino) propylamine at 55-65 ℃ in anhydrous isopropanol, performing substitution reaction on the polyethylene glycol diglycidyl ether and diethyl phosphonite at 45-55 ℃ under the action of 1,8 diazabicyclo [5.4.0] undecene, and performing quaternization reaction on the polyethylene glycol diglycidyl ether and the 3- (dimethylamino) propylamine at 35-45 ℃ to obtain the zwitterionic emulsifier; S3, preparing microgel dispersoid, namely polymerizing dextran, 2- (methacryloyloxy) ethyl dimethyl (3-sulfopropyl) ammonium inner salt and glycidyl methacrylate serving as monomers in the presence of an initiator VA044 to obtain the microgel dispersoid; S4, preparing an epoxy phosphoric acid prepolymer, namely, generating the epoxy phosphoric acid prepolymer by esterification-ring-opening reaction of bisphenol A liquid epoxy resin and phosphoric acid at 70-80 ℃; s5, preparing resin emulsion, namely shearing and pre-emulsifying an epoxy phosphoric acid prepolymer, bisphenol A epoxy resin and a zwitterionic emulsifier, then introducing a benzoxazine prepolymer and deionized water to emulsify to form a benzoxazine-epoxy-phosphoric acid composite emulsion, and finally introducing 3 glycidoxypropyl trimethoxy silane, a microgel dispersion and phytic acid into the emulsion to obtain the resin emulsion.
  2. 2. The phenolic-epoxy corrosion resistant aqueous paint of claim 1, wherein the ratio of phenol to para-aminobenzoic acid to formaldehyde solution in step S1 is 40-50g:30-36g:35-45g.
  3. 3. The phenolic-epoxy corrosion resistant aqueous paint of claim 1, wherein said polyethylene glycol diglycidyl ether, 3- (dimethylamino) propylamine, 1,8 diazabicyclo [5.4.0] undecene, diethylphosphonite, 1,3 propane sultone are used in a ratio of 55-65g:18-22g:1.3-1.7g:6.0-6.5g:22-26g in step S2.
  4. 4. The phenolic-epoxy corrosion-resistant aqueous paint of claim 1, wherein the dosage ratio of dextran, 2 (methacryloyloxy) ethyl dimethyl (3 sulfopropyl) ammonium inner salt, glycidyl methacrylate, initiator VA044 in step S3 is 16-20g:8-10g:4.5-5.5g:0.8-1.0g.
  5. 5. The phenolic-epoxy corrosion resistant water paint of claim 1, wherein said bisphenol a type liquid epoxy resin to phosphoric acid dosage ratio in step S4 is 280-320g:42-48g.
  6. 6. The phenolic-epoxy corrosion-resistant aqueous paint of claim 1, wherein the epoxy phosphate prepolymer, bisphenol a epoxy resin, zwitterionic emulsifier, benzoxazine prepolymer, deionized water, 3 glycidoxypropyl trimethoxysilane, microgel dispersion and phytic acid in step S5 are used in a ratio of 140-160g:140-160g:40-50g:65-75g:320-380ml:7-9g:110-130g:7-9g.
  7. 7. The phenolic-epoxy corrosion-resistant water-based paint according to claim 1, wherein the slurry consists of 119-132 parts of deionized water, 4.0-4.4 parts of wetting and leveling aid, 2.6-3 parts of defoamer, 158-175 parts of zinc phosphate rust-resistant pigment, 33-37 parts of flaky mica iron oxide, 33-37 parts of talcum powder and 11 parts of extinction silica.
  8. 8. The phenolic-epoxy anticorrosive water-based paint according to claim 1, wherein the wetting and leveling aid is one of BYK-333, BYK-349 and TEGO Wet270, and the defoamer is one of BYK024 and BYK-028.
  9. 9. The phenolic-epoxy corrosion resistant aqueous paint of claim 1, wherein said curing agent is EPIKURE 8530-W-75.
  10. 10. A process for the preparation of a phenolic-epoxy anticorrosive water-based paint according to any one of claims 1 to 9, characterized in that it comprises the following steps: Mixing deionized water, a wetting and leveling auxiliary agent and a defoaming agent uniformly, adding zinc phosphate rust-proof pigment, flaky mica iron oxide, talcum powder and extinction silicon dioxide, dispersing uniformly to form slurry, mixing the slurry with resin emulsion uniformly to obtain a water-based paint A component, premixing a curing agent with deionized water, adding the defoaming agent to obtain a water-based paint B component, mixing the water-based paint A component and the water-based paint B component uniformly, coating the mixture on a substrate, and curing to obtain the anti-corrosion water-based paint coating.

Description

Phenolic aldehyde-epoxy anti-corrosion water paint and preparation method thereof Technical Field The invention relates to the technical field of anti-corrosion paint, in particular to phenolic-epoxy anti-corrosion water paint and a preparation method thereof. Background In recent years, the performance requirements of industries such as ships, airplanes, high-speed rails, ocean engineering and the like on the anticorrosive paint are continuously improved, and particularly under the conditions of multi-cycle damp heat, salt fog and condensation moisture exchange, the coating is required to have excellent corrosion resistance, adhesive force and environmental stability. At present, the traditional solvent type epoxy or chlorinated rubber system is used as the main stream of high-corrosion-resistance occasions for a long time due to high crosslinking density and compact film formation, but has high organic solvent content, poor operation safety and serious environmental pollution, and is difficult to meet the current environmental protection regulations on low VOC emission, and along with the continuous enhancement of environmental awareness and the promotion of energy-saving and emission-reduction policies, the water-based corrosion-resistance system gradually becomes a development direction. However, the phenolic resin and the epoxy resin in the aqueous system have obvious differences in terms of molecular polarity, curing rate and compatibility, and the problems of wide emulsion particle size distribution, layering, slow drying, insufficient wet adhesion and the like easily occur in the system, so that the industrial application of the aqueous system is severely limited. The phenolic resin has more hydroxyl groups, good heat resistance and chemical stability, is easy to generate self-condensation in an aqueous phase to cause uneven dispersion, while the epoxy resin has excellent cohesiveness and solvent resistance, but the aggregation tendency and hydrophobicity in the aqueous phase cause poor stability of a dispersion system, uneven crosslinking to influence film forming density, the two are often subjected to phase separation or gelation phenomenon in blending emulsification, so that a paint film has high microporosity and coating compactness to further cause salt spray resistance attenuation, and meanwhile, a residual surfactant after film forming has higher mobility, is easy to form a micro-channel under long-term humid conditions to provide a passage for water vapor and ion migration to reduce the protective performance, and in addition, the aqueous system has slow energy transfer in a curing and drying stage and uneven curing inside and outside the film forming, which is easy to cause insufficient tensile strength of a surface layer, and the moisture permeation in a high-humidity or salt spray circulation environment can cause interface stress concentration and local tack-free to cause foaming and spalling of the coating. Based on the above, how to improve the compatibility of phenolic aldehyde and epoxy in an aqueous system at the same time becomes a key technical problem for solving the practical application bottleneck of the high-corrosion-resistance aqueous coating. Disclosure of Invention In view of the above, the present invention aims to provide a phenolic-epoxy anticorrosive water paint, which has high compatibility and long-term anticorrosive stability of phenolic and epoxy systems in water environment. Based on the purposes, the invention provides phenolic-epoxy anti-corrosion water paint which is formed by mixing and curing A, B components according to the mass ratio of 100:28-32; The component A comprises the following raw materials, by weight, 360-400 parts of slurry and 600-640 parts of resin emulsion; The component B comprises the following raw materials, by weight, 260-300 parts of a curing agent, 200-240 parts of deionized water and 1.5-2.5 parts of a defoaming agent; The preparation steps of the resin emulsion are as follows: s1, preparing a benzoxazine prepolymer, namely, in anhydrous 1,4 dioxane, taking phenol, para-aminobenzoic acid and formaldehyde solution as reaction raw materials, and carrying out condensation-ring closure reaction for 5-7h at 80-90 ℃ to generate the benzoxazine prepolymer; S2, preparing a zwitterionic emulsifier, namely reacting polyethylene glycol diglycidyl ether and 3- (dimethylamino) propylamine in anhydrous isopropanol at 55-65 ℃ for 2.5-3.5 hours for epoxy ring-opening reaction, reacting the polyethylene glycol diglycidyl ether and diethyl phosphonite with 1,8 diazabicyclo [5.4.0] undecene for 3-5 hours for substitution reaction under the action of 45-55 ℃, and finally carrying out quaternization reaction with 1,3 propane sultone at 35-45 ℃ for 2 hours to obtain the zwitterionic emulsifier; S3, preparing microgel dispersoid, namely polymerizing dextran, 2 (methacryloyloxy) ethyl dimethyl (3-sulfopropyl) ammonium inner salt and glycidyl methacrylate ser