Water-Based Color Clear Coating for Low-Haze Deep Color
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Solution Overview
Problem
Existing multilayer coating films struggle to achieve high chroma, brightness, and depth of color feeling while maintaining transparency, particularly in candy color coatings where reducing the amount of coloring pigment compromises chroma and brightness.
Innovation Solution
A water-based coating composition comprising specific ratios of acrylic resin emulsion, water-soluble acrylic resin, and melamine resin, along with a coloring pigment dispersion having a 90%-volume particle diameter of 100 nm or less, is used to form a color clear coating film.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the amount of coloring pigment is reduced to enhance transparency, then transparency is improved, but chroma and brightness deteriorate
Solution Approach 1:
The patent changes the particle size parameter of the coloring pigment to D90 ≤ 100 nm, which allows the pigment to maintain high chroma and brightness while having reduced light scattering effects that would compromise transparency. This parameter change enables both transparency and color intensity to coexist.
Solution Approach 2:
The patent uses a composite resin system combining acrylic resin emulsion, water-soluble acrylic resin, and melamine resin in specific ratios. This composite material system creates a matrix that optimally disperses the ultrafine pigment particles, maintaining color intensity while allowing light transmission for transparency.
2Illumination intensity
If ultrafine coloring pigment is used to maintain high chroma and brightness, then chroma and brightness are improved, but haze increases
Solution Approach 1:
The patent precisely controls the particle size parameter of the coloring pigment (D90 ≤ 100 nm) and the resin emulsion (average particle diameter ≤ 100 nm). This dual parameter control ensures pigment particles are fine enough to maintain chroma and brightness but fine enough to minimize light scattering that causes haze.
Solution Approach 2:
The patent creates local quality differences by having the pigment particles and resin emulsion particles both at ultrafine scales (≤100 nm), creating a homogeneous nanoscale dispersion that maintains optical clarity while providing intense color where needed.
3Quantity of substance
If resin particle size is reduced to improve transparency, then transparency is improved, but manufacturing complexity increases
Solution Approach 1:
The patent specifies a clear parameter threshold (average particle diameter ≤ 100 nm) for the resin emulsion, providing a straightforward manufacturing target. This single parameter specification simplifies the manufacturing process by giving clear guidance on the required emulsion fineness without requiring complex multi-parameter optimization.
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 results in a coating film with low haze and high transparency, maintaining high chroma and brightness, thus enhancing the depth of color feeling without reducing the coloring pigment content.
Implementation Method 1
an acrylic resin emulsion (A) having an average particle diameter of 100 nm or less
Implementation Method 2
a melamine resin (C) in an amount of 20 to 40% by mass in terms of the resin solid content of the coating film-forming resin (i)
Implementation Method 3
the coloring pigment dispersion (ii) comprises a coloring pigment (D) having a 90%-volume particle diameter (D90) of 100 nm or less
Data Source
AI summary
A challenge of the present invention is to provide a water-based coating composition capable of providing a design superior in depth feeling in the formation of a multilayer coating film having a so-called color clear coating film. The present invention relates to a water-based coating composition comprising a coating film-forming resin (i) and a coloring pigment dispersion (ii), wherein the coating film-forming resin (i) comprises: an acrylic resin emulsion (A) having an average particle diameter of 100 nm or less in an amount of 10 to 60% by mass in terms of the resin solid content of the coating film-forming resin (i), a water-soluble acrylic resin (B) in an amount of 5 to 40% by mass in terms of the resin solid content of the coating film-forming resin (i), and a melamine resin (C) in an amount of 20 to 40% by mass in terms of the resin solid content of the coating film-forming resin (i); and the coloring pigment dispersion (ii) comprises a coloring pigment (D) having a 90%-volume particle diameter (D90) of 100 nm or less.