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CN-121991574-A - Composite modified resin anticorrosive paint and preparation method thereof

CN121991574ACN 121991574 ACN121991574 ACN 121991574ACN-121991574-A

Abstract

The invention discloses a composite modified resin anticorrosive paint and a preparation method thereof, and belongs to the technical field of paint. The method comprises the steps of taking aqueous epoxy resin as a film forming matrix, firstly preparing graphene oxide, introducing covalently bonded amino and sulfonic groups through amination of 2, 5-diaminobenzenesulfonic acid, carrying out defect engineering reduction through hydrazine hydrate to obtain defect engineering amino modified graphene oxide with high-density reaction sites, then growing layered double hydroxide on the surface of the graphene oxide in situ, inserting molybdic acid root to construct core-shell structured filler, and finally dispersing the filler in an aqueous epoxy/aliphatic polyamide amine curing system to obtain the composite anticorrosive paint. The invention obviously improves the adhesive force and impact resistance of the coating and the metal matrix, reduces the water absorption, enhances the shielding and slow-release corrosion inhibition capability to corrosive media, and shows long-term corrosion resistance superior to that of the conventional water-based epoxy anti-corrosion coating in neutral salt spray and low-frequency impedance tests.

Inventors

  • LI LITAO
  • LI ZHIHENG
  • WANG ZHEN

Assignees

  • 增城市柏雅化工有限公司

Dates

Publication Date
20260508
Application Date
20260318

Claims (8)

  1. 1. The preparation method of the composite modified resin anticorrosive paint is characterized by comprising the following steps of (1) reacting 2-8 parts of graphite powder, 10-30 parts of concentrated sulfuric acid, 1 part of sodium nitrate and 2-10 parts of potassium permanganate in an ice bath, then heating to 40-80 ℃ and stirring for 8 hours, adding 2-4 parts of hydrogen peroxide for reduction, centrifugally washing to be neutral, and carrying out vacuum drying at 50-70 ℃ for 8-16 hours to obtain graphene oxide; dispersing 1 part of graphene oxide obtained in the step (1) and 1 part of 2, 5-diaminobenzenesulfonic acid in ultrapure water respectively, mechanically stirring for 30-50min at 70-90 ℃ after mixing, vacuum drying at 50-70 ℃ to obtain amino modified graphene oxide, (3) dispersing 1 part of amino modified graphene oxide obtained in the step (2) in water, adding 0.1 part of hydrazine hydrate, reducing for 2h at 60 ℃, centrifugally washing and drying to obtain defect engineering amino modified graphene oxide, (4) dispersing 1 part of defect engineering amino modified graphene oxide obtained in the step (3), 2-6 parts of zinc nitrate hexahydrate, 1-3 parts of aluminum nitrate nonahydrate and 1 part of sodium molybdate dihydrate in 50-150 parts of deionized water, dropwise adding 2mol/L sodium hydroxide solution to regulate pH to 10,70-90 ℃ for 8-16h, centrifugally washing and drying at 70-90 ℃ to obtain core-shell structured filler, (5) ageing 60-80 parts of aqueous epoxy resin emulsion, 20-40 parts of aqueous epoxy agent, and (3) 0.1-0.5 part of the core-shell structured filler obtained in the step (4) is subjected to ultrasonic dispersion for 0.5-1.5 hours, mechanically stirred uniformly, sprayed on a base material, and cured at room temperature for 12-36 hours to obtain the composite modified resin anticorrosive paint.
  2. 2. The preparation method of the composite modified resin anticorrosive paint according to claim 1, wherein the ice bath temperature in the step (1) is 0-5 ℃, the heating rate is 1-2 ℃ per minute, the stirring speed is 200-300rpm, and the interlayer spacing of graphene oxide is 0.7-0.8nm.
  3. 3. The method for preparing a composite modified resin anticorrosive paint according to claim 1, wherein the concentration after dispersion in the step (2) is 0.5-1.5mg/mL, and the stirring speed is 300-500rpm.
  4. 4. The method for preparing the composite modified resin anticorrosive paint according to claim 1, wherein the reduction temperature in the step (3) is 55-65 ℃.
  5. 5. The method for preparing the composite modified resin anticorrosive paint according to claim 1, wherein the aging temperature in the step (4) is 75-85 ℃ and the aging speed is 100-200rpm.
  6. 6. The preparation method of the composite modified resin anticorrosive paint according to claim 1, wherein the core-shell filler in the step (5) is added in an amount of 0.2 part, the ultrasonic dispersion frequency is 20-40kHz, the spraying thickness is 30-50 μm, and the curing humidity is less than 60% RH.
  7. 7. The preparation method of the composite modified resin anticorrosive paint according to claim 1, wherein the dripping rate of sodium hydroxide in the step (4) is 0.1-0.5mL/min, the pH is controlled to be 9.5-10.5, and the specific surface area of the core-shell filler is 150-250m 2 /g.
  8. 8. A composite modified resin anticorrosive paint is characterized in that the composite modified resin anticorrosive paint is obtained by the preparation method of any one of claims 1-7.

Description

Composite modified resin anticorrosive paint and preparation method thereof Technical Field The invention belongs to the technical field of paint, and particularly relates to a composite modified resin anticorrosive paint and a preparation method thereof. Background Metal corrosion is one of key problems restricting service life and safety of equipment, and according to statistics, the direct economic loss caused by metal corrosion each year accounts for a plurality of percent of the total national production value, so that the metal corrosion has important engineering significance for long-acting protection of steel structures, storage tanks, pipelines, marine engineering facilities and the like in a coating mode. The traditional solvent type epoxy anticorrosive paint is widely applied to the heavy-duty anticorrosive field due to compact film formation and good chemical medium resistance, but has large volatilization amount of organic solvent and high emission of Volatile Organic Compounds (VOC), so that the increasingly strict environmental protection regulation requirement is difficult to meet. Compared with the prior art, the water-based epoxy anticorrosive paint has the advantages of low VOC, high construction safety, easy cleaning of tools and the like by replacing most of organic solvents with water, and gradually becomes an important development direction in the heavy-duty anticorrosive field. However, the existing water-based epoxy coating still has the problems of insufficient adhesive force, larger brittleness, poor impact resistance, limited capability of shielding corrosive media and the like under the long-term service condition, and restricts the popularization and application of the water-based epoxy coating in a severe corrosion environment. At present, main approaches for improving the performance of the epoxy anti-corrosion coating comprise strategies such as nanoparticle modification, micro/nano container introduction, biological base material modification and the like, and the mechanical property and the anti-corrosion service life of the coating are improved by constructing a multi-scale composite structure. Wherein, the nano filler is utilized to form a 'labyrinth effect' in the coating, so that the diffusion path of the corrosive medium to the metal matrix is prolonged, and the method is one of effective methods for improving the shielding performance. Common nanofillers comprise nano silicon dioxide, nano aluminum oxide, carbon nano tubes, graphene, derivatives thereof and the like, and the materials can improve the compactness and corrosion resistance of the coating to a certain extent by virtue of high specific surface area and excellent mechanical properties. However, the interface compatibility of part of inorganic nano particles and the organic resin matrix is poor, agglomeration and interface defects are easy to form in the coating, and a rapid infiltration channel is provided for corrosive media, so that the long-term protection effect of the coating is difficult to fully exert. Graphene Oxide (GO) has a high specific surface area, excellent mechanical properties and good barrier properties, and is considered as a potentially preferred filler for modified epoxy corrosion protection coatings. By introducing a small amount of graphene oxide sheets with good dispersion into the epoxy matrix, the migration path of corrosive media such as water, oxygen, chloride ions and the like can be obviously prolonged, so that the shielding performance and electrochemical impedance of the coating are improved. However, graphene oxide is still easy to stack and agglomerate among sheets in an aqueous resin system, and the interface effect between an oxygen-containing functional group and a resin matrix is limited, so that the dispersion stability of the graphene oxide in a coating is insufficient, and structural defects such as holes, microcracks and the like are easy to induce. To improve this problem, prior studies have attempted to modify the graphene oxide surface by small molecules, polymers or silane coupling agents, introducing hydrophilic functional groups or reactive groups, to improve its dispersibility in aqueous epoxy and interfacial bonding strength. Although the methods improve the dispersion and compatibility of graphene oxide to a certain extent, the modified structure mainly comprises physical adsorption or single functional groups, and multiple requirements of covalent bonding, hydrophilic dispersion, subsequent directional growth of inorganic shells and the like are difficult to be simultaneously met. On the other hand, in order to achieve both physical shielding and chemical corrosion inhibition functions, inorganic corrosion inhibition materials such as layered double hydroxides (layered double hydroxides, LDH) and the like are widely paid attention to in water-based anticorrosive coatings. LDH is composed of positively charged metal hydroxide laminate and interlayer