Anticorrosion Primer with Layered Double Hydroxides
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for corrosion protection of metallic substrates rely heavily on chromium-containing compounds, which are toxic and carcinogenic, and fail to provide adequate protection when attempting to simplify the coating process by dispensing with conversion layers.
Innovation Solution
A method involving the direct application of a corrosion protection primer containing an organic polymer binder and synthetic layered double hydroxides with organic anions to metallic substrates, forming a polymer film for enhanced corrosion resistance without the need for conversion layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If chromates are used as anti-corrosion pigments in organic polymer primers, then corrosion protection is improved, but toxicity and environmental harm increase
Solution Approach 1:
The patent replaces harmful chromates with layered double hydroxide (LDH) structures that can safely encapsulate and release corrosion-inhibiting species. The LDH structure itself is benign, but it provides the same protective function by controlling the release of inhibitors like benzotriazole or DMTD, converting a harmful approach into a beneficial one.
Solution Approach 2:
The patent changes the chemical composition parameter from chromate-based inhibitors to LDH-encapsulated organic inhibitors. This parameter change maintains the corrosion protection function while eliminating the toxicity issue, as the LDH structure provides controlled release of non-toxic inhibiting species.
2Device complexity
If conversion layers are eliminated to simplify the coating process, then manufacturing complexity is reduced, but corrosion protection reliability deteriorates
Solution Approach 1:
The patent merges the functions of the conversion layer and the primer into a single integrated coating system. The LDH-containing primer directly adheres to the metal substrate, combining the corrosion inhibition functions of both traditional layers into one application step, thus simplifying the process while maintaining protection reliability.
Solution Approach 2:
The LDH-containing primer performs multiple functions simultaneously: it provides adhesion to the substrate, delivers corrosion inhibition through controlled release of inhibitors, and forms a protective film. This multi-functionality replaces the need for separate conversion layers, achieving both simplification and reliable protection.
3Reliability
If multiple coating layers are applied to ensure adequate corrosion protection, then corrosion resistance is improved, but manufacturing time and cost increase
Solution Approach 1:
The patent combines multiple protective functions into a single primer layer containing LDH. Instead of applying separate conversion layers and primers, the LDH-primer integrates corrosion inhibition, adhesion, and protection functions, reducing the number of coating steps while maintaining or improving corrosion resistance.
Solution Approach 2:
The LDH structure is pre-formed with encapsulated corrosion inhibitors before application. This preliminary preparation allows the single primer layer to deliver sustained corrosion protection over time, equivalent to or better than multiple layers, thereby improving processing efficiency without sacrificing protection reliability.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach provides excellent corrosion protection, allowing the elimination of chromium-containing agents and simplifying the coating process, thereby combining effective corrosion resistance with economic advantages in demanding industries like automotive and aviation.
Implementation Method 1
synthetic, layered double hydroxide containing organic anions
Implementation Method 2
layered double hydroxide containing organic anions is applied directly to a metallic substrate
Data Source
AI summary
The present invention relates to a method for producing an anticorrosion coating, in which (1) an anticorrosion priming agent containing (A) at least one organic resin as a binder and (B) at least one synthetic, layered double hydroxide that contains organic anions is applied directly to a metallic substrate, and (2) a polymer film is formed from the anticorrosion priming agent applied in step (1), the method being characterised in that the at least one synthetic, layered double hydroxide (B) comprises at least one organic anion of the following formula (I): where R1=COO-, SO3 -, R2/R3 = NH2, OH, H. The present invention additionally relates to coated metallic substrates that have been coated according to the method of the invention. The present invention also relates to the use of the anticorrosion priming agent that is to be used in the method of the invention for improving the corrosion resistance of metallic substrates.