Zirconium-Copper Surface Treatment for Cation Electrodeposition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Zirconium ion surface treatments for metal base materials used in cation electrodeposition coating often fail to achieve sufficient throwing power and anti-corrosion properties, particularly on cold-rolled steel plates, leading to incomplete coating and inferior performance.
Innovation Solution
A metal surface treatment liquid comprising zirconium ions, copper ions, and other metal ions such as tin, indium, or aluminum, along with a hydrolysis condensate of aminosilane, within specific concentration ranges and pH levels, is used to enhance throwing power and anti-corrosion properties by forming a stable zirconium oxide coating film and improving adhesiveness through interactions between copper and zirconium ions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If zirconium ion surface treatment is used to replace zinc phosphate treatment, then environmental friendliness is improved (no sludge generation), but throwing power of subsequent cation electrodeposition coating deteriorates
Solution Approach 1:
The patent combines multiple metal ions (zirconium, copper, and other metal ions selected from tin, indium, aluminum, niobium, tantalum, yttrium, or cerium) in a single surface treatment composition. This merging of different ionic components allows the system to simultaneously achieve environmental benefits (no sludge) and functional performance (sufficient throwing power for electrodeposition), resolving the contradiction between eco-friendliness and coating quality.
Solution Approach 2:
The invention creates a composite inorganic coating film containing multiple metal elements (zirconium, copper, and at least one other metal ion) on the metal base material surface. This composite structure provides both the environmental advantage of replacing zinc phosphate treatments and the functional advantage of enabling proper throwing power for subsequent cation electrodeposition coating.
2Reliability
If zirconium ion concentration is increased to improve anti-corrosion properties, then coating stability is improved, but coating cost and complexity increase
Solution Approach 1:
The patent specifies precise concentration ranges for each metal ion component: zirconium ions (10-10,000 ppm), copper ions (0.005-1 times the zirconium concentration by mass), and other metal ions (0.1-1,000 times the copper concentration by mass). By optimizing these parameters within defined ranges, the invention achieves superior anti-corrosion properties while controlling composition complexity and manufacturing cost.
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 effectively improves throwing power and anti-corrosion properties by forming a stable zirconium oxide coating film and enhancing adhesiveness, allowing for uniform electrodeposition and superior corrosion resistance, as demonstrated by improved film thickness ratios and performance in stringent tests like SDT and CCT.
Implementation Method 1
forming a stable zirconium oxide coating film
Implementation Method 2
enhancing adhesiveness through interactions between copper and zirconium ions
Implementation Method 3
a hydrolysis condensate of aminosilane compound, which has been obtained by carrying out hydrolysis condensation of a silane coupling agent having an amino group
Implementation Method 4
cation electrodeposition coating
Implementation Method 5
a property of allowing automobile bodies having a complicated shape to be completely coated
Data Source
Figure 1~2
AI summary
A surface treatment with a zirconium ion that enables sufficient throwing power and superior anti-corrosion properties to be exhibited when thus surface treated metal base material is subjected to cation electrodeposition coating is provided. A metal surface treatment liquid thereof for cation electrodeposition coating includes zirconium ions, copper ions, and other metal ions, and having a pH of 1.5 to 6.5, in which: the other metal ions are at least one selected from the group consisting of tin ions, indium ions, aluminum ions, niobium ions, tantalum ions, yttrium ions and cerium ions; the concentration of zirconium ions is 10 to 10,000 ppm; the concentration ratio of the copper ions to the zirconium ions is 0.005 to 1 on a mass basis; and the concentration ratio of the other metal ions to the copper ions is 0.1 to 1,000 on a mass basis.