CN-122011849-A - Modified hydrotalcite reinforced soluble polytetrafluoroethylene anticorrosive paint and preparation method of coating thereof

CN122011849ACN 122011849 ACN122011849 ACN 122011849ACN-122011849-A

Abstract

The invention discloses a modified hydrotalcite reinforced soluble polytetrafluoroethylene anticorrosive paint and a coating preparation method thereof, relates to the field of metal surface protection, and solves the technical problems of poor interfacial compatibility of hydrotalcite and soluble polytetrafluoroethylene, limited hydrotalcite addition, and poor barrier anticorrosive performance of the coating. The invention uses specific anionic surfactant to modify hydrotalcite, and combines the modified hydrotalcite with soluble polytetrafluoroethylene according to a certain proportion to prepare the anti-corrosion coating, and the coating is coated on the surface of a metal substrate by electrostatic spraying and is thermally solidified at high temperature to obtain the anti-corrosion coating. The invention greatly improves the interfacial compatibility of hydrotalcite and soluble polytetrafluoroethylene, realizes high addition of hydrotalcite and complete coating structure, and the structure and hydroxyl action of modified hydrotalcite cooperate to strengthen the barrier property of the coating, so that the process is controllable and is suitable for industrial production, and the coating can meet the metal protection requirement of severe corrosion environment.

Inventors

HAN JINGBIN
WANG CHENG
ZHANG TAO
LIU FANGZHONG
YANG ZEYA
CHEN BAIQIANG
LIU ZHIWEN

Assignees

衢州资源化工创新研究院
北京化工大学
衢州佰强新材料科技有限公司

Dates

Publication Date: 20260512
Application Date: 20260331

Claims (9)

1. The modified hydrotalcite enhanced soluble polytetrafluoroethylene anticorrosive paint is characterized by comprising surfactant modified hydrotalcite and soluble polytetrafluoroethylene, wherein the mass of the surfactant modified hydrotalcite is 0.1-5% of that of the soluble polytetrafluoroethylene; the surfactant is at least one of sodium dodecyl sulfate, sodium dodecyl sulfonate, lithium dodecyl sulfate, ammonium dodecyl sulfate and sodium laureth sulfate.
2. The modified hydrotalcite-enhanced soluble polytetrafluoroethylene anticorrosive coating according to claim 1, wherein the mass of said surfactant-modified hydrotalcite is 4% of the mass of said soluble polytetrafluoroethylene.
3. The modified hydrotalcite reinforced soluble polytetrafluoroethylene anticorrosive coating according to claim 1 wherein the hydrotalcite is one of magnesium aluminum hydrotalcite, cobalt aluminum hydrotalcite, calcium aluminum hydrotalcite and zinc aluminum hydrotalcite.
4. A process for preparing a modified hydrotalcite enhanced soluble polytetrafluoroethylene anticorrosive coating according to any one of claims 1 to 3, comprising the steps of: mixing hydrotalcite and a surfactant in water, reacting for 12-24 hours at 50-90 ℃, and drying after the reaction is finished to obtain the surfactant modified hydrotalcite; and mixing the surfactant modified hydrotalcite and the soluble polytetrafluoroethylene in an organic solvent, and drying to remove the solvent to obtain the modified hydrotalcite reinforced soluble polytetrafluoroethylene anticorrosive paint.
5. The method according to claim 4, wherein the organic solvent is absolute ethanol.
6. The preparation method of the modified hydrotalcite reinforced soluble polytetrafluoroethylene anticorrosive coating is characterized by comprising the following steps of: Spraying the modified hydrotalcite-enhanced soluble polytetrafluoroethylene anticorrosive paint according to any one of claims 1-3 on the surface of a metal substrate by adopting an electrostatic spraying mode, and then thermally curing and cooling to obtain the modified hydrotalcite-enhanced soluble polytetrafluoroethylene anticorrosive paint.
7. The method according to claim 6, wherein the heat curing is performed at 365-375 ℃ for 0.2-5 hours.
8. The preparation method of the electrostatic spraying device according to claim 6, wherein the parameters of the electrostatic spraying are 90-100 kV in voltage and 70-80 mu A in current.
9. The modified hydrotalcite-enhanced soluble polytetrafluoroethylene anticorrosive coating prepared by the preparation method according to any one of claims 6 to 8.

Description

Modified hydrotalcite reinforced soluble polytetrafluoroethylene anticorrosive paint and preparation method of coating thereof Technical Field The invention relates to the field of metal surface protection, in particular to a modified hydrotalcite-enhanced soluble polytetrafluoroethylene anticorrosive paint and a coating preparation method thereof. Background The metal material has excellent mechanical properties, is widely applied to a plurality of industrial fields such as petrochemical industry, ocean engineering, transportation, building facilities and the like, and is a core base material in industrial production and engineering construction. However, in natural and industrial environments, the metal material is extremely easy to generate chemical or electrochemical reaction with water, oxygen, acid-base salt and other mediums to generate corrosion, so that not only can the loss and huge economic loss of the metal material be caused, but also serious safety accidents such as equipment operation failure and engineering structure collapse can be caused, and therefore, the research and development of efficient and long-acting metal corrosion prevention technology and material become a key technical problem to be solved urgently in the field of chemical industry corrosion prevention. Soluble Polytetrafluoroethylene (PFA) is used as a fluororesin material with excellent performance, and has outstanding chemical stability due to the existence of a large number of fluorocarbon bonds with bond energy of up to 485.6kJ/mol in molecules, so that the material becomes a common base material in the field of anticorrosive coatings. However, under the influence of high electronegativity of fluorine atoms, adjacent fluorine atoms in the soluble polytetrafluoroethylene molecules repel each other for maintaining the minimum energy of a system, so that the molecular structure of the soluble polytetrafluoroethylene molecules is spirally arranged, and a large number of pores are formed in the structure, and become permeation paths of corrosive substances such as water, oxygen and the like, so that the physical barrier property of the pure soluble polytetrafluoroethylene coating is poor, the corrosive substances easily contact a metal substrate through a coating, the corrosion resistance is greatly reduced, and the long-acting corrosion resistance requirement of a severe corrosion environment is difficult to meet. In order to improve the barrier property of the soluble polytetrafluoroethylene coating, the prior art tries to modify the nano filler by adopting three-dimensional nano particles as the filler, wherein the three-dimensional nano particles can prolong the transmission path of corrosive substances to a certain extent, but have limited barrier effect, so that the problem of pore permeation of the soluble polytetrafluoroethylene coating cannot be fundamentally solved, hydrotalcite (LDHs) is used as an inorganic intercalation functional material with a multi-layer lamellar structure, and has excellent barrier potential as a two-dimensional filler, the lamellar structure can enable the corrosive substances to form a 'tortuous path' in the permeation process, the permeation distance is obviously prolonged (as shown in figure 1), meanwhile, hydroxyl groups rich on the surface of the hydrotalcite nano sheets can form hydrogen bonds with the permeable substances, the capture of water molecules is realized, a hydrogen bond network can occupy gaps of the soluble polytetrafluoroethylene coating, the free movement of a high molecular chain is inhibited, the free volume of a film is reduced, and the barrier property of the coating is synergistically enhanced from multiple aspects. However, hydrotalcite is an inorganic material, and has serious interfacial compatibility with organic soluble polytetrafluoroethylene, which becomes a core technical bottleneck for restricting the application of hydrotalcite in soluble polytetrafluoroethylene anticorrosive paint. In the prior art, on the premise of ensuring the structural integrity of the coating and no cracking and pulverization, the addition amount of hydrotalcite in soluble polytetrafluoroethylene is only 1 percent at most, the two-dimensional barrier advantage of hydrotalcite cannot be fully exerted by the lower addition amount, the improvement effect on the barrier performance of the coating is very small, and if the addition amount of hydrotalcite is blindly improved, the defects of cracking, falling off and the like of the coating caused by poor compatibility of the hydrotalcite and the hydrotalcite can lose the anti-corrosion effect. Aiming at the technical bottleneck, no effective solution is found in the field, and the compatibility of the high addition amount of hydrotalcite and the integrity of the soluble polytetrafluoroethylene coating cannot be realized, so that the research and development of an anticorrosive paint and a preparation process which can improve the interf