Metal Surface Pretreatment Copolymer Corrosion Delamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing anticorrosion pretreatment methods for metallic surfaces, particularly steel and galvanized steel, fail to adequately prevent corrosion delamination, despite the use of acid-stable polymers.
Innovation Solution
An aqueous composition comprising a copolymer with alternating monomer units including carboxylic acid groups and non-acid groups, combined with an acidic aqueous composition containing titanium, zirconium, or hafnium compounds, is applied to the metallic surface in various sequences to enhance corrosion protection and adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If acid-stable polymers are added to aqueous compositions for anticorrosion pretreatment, then adhesion of further layers is improved, but corrosion delamination still occurs on steel and galvanized steel surfaces
Solution Approach 1:
The patent applies composite materials by combining copolymers with alternating monomer units (containing carboxylic acid groups) and titanium/zirconium/hafnium compounds to form a composite pretreatment layer. This composite structure provides both adhesion enhancement from the polymer and corrosion protection from the metal compounds, resolving the contradiction between improving adhesion and preventing corrosion delamination
Solution Approach 2:
The patent changes the chemical parameters of the polymer by using copolymers with alternating monomer units containing carboxylic acid groups, which can form strong chemical bonds with metal surfaces. This parameter change enables the polymer to provide both adhesion and corrosion protection simultaneously, rather than just adhesion as with conventional polymers
2Ease of manufacture
If conventional pretreatment methods are used on steel and galvanized steel, then processing is simple, but corrosion delamination cannot be prevented
Solution Approach 1:
The patent creates a universal pretreatment composition that works on multiple metal substrates (steel, galvanized steel, aluminum, magnesium) with a single formulation. The composition performs multiple functions: surface conditioning, adhesion promotion, and corrosion protection, eliminating the need for different pretreatment methods for different metals while providing reliable corrosion protection
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
The process significantly improves corrosion protection and adhesion, forming a barrier against corrosive salts and enhancing the properties of the deposited layers, effectively addressing corrosion delamination issues.
Implementation Method 1
The metallic surface is brought into contact with an aqueous composition A which comprises a) from 0.01 to 0.5 g/l (calculated as solid addition) of at least one copolymer comprising, in an alternating configuration, i) monomer units which comprise at least one carboxylic acid group
Implementation Method 2
b1) at least one compound selected from the group consisting of titanium, zirconium and hafnium compounds
Data Source
AI summary
Described herein is an improved process for an anticorrosion pretreatment of a metallic surface including steel, galvanized steel, aluminum, magnesium and/or a zinc-magnesium alloy, wherein the metallic surface is brought into contact with an aqueous composition A including a) from 0.01 to 0.5 g/l of a copolymer and the metallic surface is brought into contact with an acidic aqueous composition B including b1) a compound selected from the group consisting of titanium, zirconium and hafnium compounds, wherein the metallic surface is brought into contact i) firstly with the composition A and then with the composition B, ii) firstly with the composition B and then with the composition A and/or iii) simultaneously with the composition A and the composition B.Also described herein is a corresponding aqueous composition A, an aqueous concentrate for producing this composition, a correspondingly coated metallic surface and a method of using a correspondingly coated metallic substrate.