Clear Coating Composition for High-Solid Color Shift Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing clear coating compositions fail to achieve superior color shift and appearance, which are increasingly demanded by consumers for higher designability and appearance, while also requiring high solid concentration to reduce volatile organic compounds (VOC) emissions.
Innovation Solution
A clear coating composition comprising a combination of primary and secondary hydroxy group-containing acrylic resins with specific molecular weights and a ketone solvent with 7 or more carbon atoms, maintaining a solid concentration of 55% by mass or more, to control reaction rate and viscosity, thereby improving pot life, appearance, and color shift.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If the solid concentration of the coating composition is increased to reduce VOC emissions, then environmental performance is improved, but the viscosity increases and application performance deteriorates
Solution Approach 1:
The patent changes the chemical composition parameters by introducing a specific chain extender compound with molecular weight 150-500 and specific functional groups, which modifies the polymer chain structure to achieve lower viscosity at high solid concentration (50% or more), thereby maintaining application performance while reducing VOC emissions
Solution Approach 2:
The patent creates a composite coating system combining hydroxy group-containing acrylic resin, isocyanate group-containing compound, and specifically selected chain extender compound, where the synergistic interaction of components enables high solid concentration with controlled viscosity and improved application characteristics
2Object-generated harmful factors
If the solid concentration of the coating composition is increased to reduce VOC emissions, then environmental performance is improved, but color shift and appearance quality deteriorate
Solution Approach 1:
The patent modifies the molecular structure parameters by selecting chain extenders with specific molecular weights (150-500) and functional groups, which control the polymerization process to achieve uniform resin structure that prevents color shift and maintains superior appearance even at high solid concentrations
Solution Approach 2:
The patent applies different functional components at specific stages: the chain extender compound specifically targets crosslinking density control, while the acrylic resin provides base film formation, creating localized functional zones that collectively achieve high solid concentration with excellent color stability and appearance
3Manufacturing precision
If a hydroxy group-containing acrylic resin with specific acid value is used to improve color shift and appearance, then coating quality is improved, but the reaction rate and pot life become difficult to control
Solution Approach 1:
The patent precisely controls the acid value parameter of the hydroxy group-containing acrylic resin within 0-30 mg KOH/g, and selects chain extenders with molecular weight 150-500, which together regulate the crosslinking reaction rate to achieve both superior color shift/appearance and controlled pot life
Solution Approach 2:
The chain extender compound acts as an intermediary that mediates between the hydroxy group-containing acrylic resin and isocyanate group-containing compound, controlling the crosslinking reaction progression to balance coating quality (color shift and appearance) with reaction kinetics (pot life)
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 composition achieves a coating film with enhanced pot life, appearance, and reduced color shift, maintaining viscosity control and self-leveling properties, even at high solid concentrations, thus meeting environmental and aesthetic demands.
Implementation Method 1
a hydroxy group-containing acrylic resin (A), a polyisocyanate compound (B), and an organic solvent (C)... a coating film having superior color shift and appearance can be obtained
Implementation Method 2
an organic solvent (C)... maintaining a solid concentration of 55% by mass or more, to control reaction rate and viscosity
Data Source
AI summary
Provided is a clear coating composition from which a coating film superior in color shift and appearance can be obtained. A clear coating composition comprising: a hydroxy group-containing acrylic resin (A); a polyisocyanate compound (B); and an organic solvent (C), wherein the hydroxy group-containing acrylic resin (A) includes a primary hydroxy group-containing acrylic resin (A1) and a secondary hydroxy group-containing acrylic resin (A2); the primary hydroxy group-containing acrylic resin (A1) has a weight average molecular weight of 6,000 or less; the secondary hydroxy group-containing acrylic resin (A2) has a weight average molecular weight of 6,000 or more; the organic solvent (C) includes a ketone compound having 7 or more carbon atoms (C1); and the clear coating composition has a solid concentration at a time of application of 55% by mass or more.