Chrome-Free Polyurethane-Silicon Oxide Metal Surface Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current hexavalent chrome-free surface treatments for steel sheets lack sufficient corrosion resistance, alkali resistance, solvent resistance, and paint adhesion, and often require high temperatures for curing, which complicates industrial application.
Innovation Solution
A surface treatment agent combining polyurethane resin with silicon oxide, silanol groups, and specific bonding agents to create a crosslinked film structure with optimal ratios of urea and urethane bonds, allowing for improved adhesion, corrosion resistance, and lower curing temperatures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a chromate treatment is used to provide anti-rust and paint adhesion, then corrosion resistance and paint adhesion are improved, but environmental harm increases due to hexavalent chrome content
Solution Approach 1:
The invention changes the chemical composition parameters by replacing hexavalent chrome with specific combinations of inorganic compounds (phosphate, silicate, sulfate) and organic compounds (urethane resin, carboxylic acid), achieving corrosion resistance without harmful substances
Solution Approach 2:
The invention uses composite material approach by combining multiple inorganic compounds with organic compounds to create a surface treatment layer that provides both corrosion resistance and environmental compatibility
2Ease of operation
If an organic film is used to substitute chromate treatment, then formability is improved, but adhesion to overcoating paint deteriorates and marks occur during machining
Solution Approach 1:
The invention combines organic compounds (urethane resin) with inorganic compounds (phosphate, silicate, sulfate) to create a composite surface treatment that maintains formability while providing adequate adhesion to overcoating paint
Solution Approach 2:
The invention applies different functional components to different aspects of the surface treatment: organic compounds provide formability and base adhesion, while inorganic compounds provide corrosion resistance and enhanced paint adhesion
3Ease of operation
If the urethane resin structure is not optimized, then film formability is improved, but alkali resistance, workability, and solvent resistance deteriorate
Solution Approach 1:
The invention optimizes the chemical structure parameters of the urethane resin by controlling the ratio of hydroxyl groups to isocyanate groups and adjusting the molecular weight and composition to achieve both formability and resistance properties
Solution Approach 2:
The invention creates a composite system where the urethane resin structure is combined with inorganic compounds, allowing the organic component to provide formability while the inorganic component enhances resistance to alkali and solvents
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 solution provides a hexavalent chrome-free surface treatment with enhanced corrosion resistance, alkali resistance, solvent resistance, and paint adhesion, while allowing for lower temperature processing, making it more industrially viable.
Implementation Method 1
the polyurethane resin contains bond due to siloxane bond, dehydration-condensation bond of silanol group and different functional group
Implementation Method 2
by first obtaining a surface treatment agent by mixing polyurethane resin and silicon oxide... through a stable and good crosslinking reaction
Data Source
AI summary
The present invention provides a surface-treated metal material having a film formed on at least a portion of a surface of a metal material, the film containing at least polyurethane resin and silicon oxide, and a metal surface treatment agent used to obtain the surface-treated metal material. The polyurethane resin contains one or more of siloxane bond, dehydration-condensation bond of silanol group and different functional group, and silanol moiety, and urea bond. The sum of the siloxane bond, the dehydration-condensation bond of silanol group and different functional group, total amount of the silanol moiety, and the silicon oxide falls within a range of equal to or more than 1.6 wt % to equal to or less than 25 wt % for solids of the film. The ratio of the total amount of urea bond and urethane bond to the total amount of resin components falls within a range of equal to or more than 0.1 wt % to equal to or less than 10 wt %.