Multiphase Acrylic Polymer Coating for Automotive Gloss and Flop
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing aqueous coating compositions for base coat/clear coat systems in the automotive industry face challenges in achieving high gloss and flop while maintaining mechanical and chemical resistance, with current solutions often compromising on one or more of these properties.
Innovation Solution
A polyacrylate dispersion comprising a multiphase acrylic polymer, specifically formulated with vinyl polymer phases containing cycloalkyl methacrylates, hydroxyalkyl methacrylates, and acid functional monomers, which is used in conjunction with a polyurethane dispersion and a polyisocyanate crosslinker to create an aqueous coating composition that enhances adhesion, chemical resistance, and maintains high gloss and flop.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a base coat/clear coat system is used to obtain high gloss, then the gloss is improved, but the flop of the metallic pigment may be compromised due to modification of the underlying base coat
Solution Approach 1:
The base coat is formulated with crosslinked polymer microparticles and pseudoplastic or thixotropic characteristics in advance, creating a stable foundation that prevents modification when the clear coat is applied subsequently. This preliminary structuring of the base coat ensures it maintains its metallic pigment orientation and flop characteristics throughout the clear coat application process.
2Stability of the object's composition
If crosslinked polymer microparticles are used in the base coat to withstand top coat application, then the stability is improved, but the device complexity increases
Solution Approach 1:
The base coat composition is designed as a composite system combining crosslinked polymer microparticles (0.01-10 microns diameter) dispersed in an aqueous medium, with pseudoplastic or thixotropic rheology modifiers. This composite structure provides enhanced film stability and resistance to top coat application while maintaining manageable application properties through the pseudoplastic/thixotropic characteristics.
3Shape
If metallic pigments are used to obtain high flop, then the flop is improved, but the mechanical and chemical resistance may be compromised
Solution Approach 1:
The coating system is designed as a composite where metallic pigments are suspended in a base coat containing crosslinked polymer microparticles and pseudoplastic/thixotropic agents. The crosslinked polymer network provides the mechanical strength and chemical resistance, while the metallic pigments provide the flop effect, and the pseudoplastic/thixotropic properties ensure proper application and pigment orientation without compromising the protective matrix.
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 proposed solution provides a coating system with excellent chemical resistance, improved adhesion to plastics, and high gloss and flop performance, making it suitable for automotive applications without the need for additional primers, while being environmentally friendly by avoiding chlorinated polyolefins.
Implementation Method 1
The multiphase acrylic polymer is prepared in 2 or more steps by emulsion polymerization
Implementation Method 2
the multiphase acrylic polymer comprises at least two (polymer) phases
Implementation Method 3
an aqueous coating composition comprising the polyacrylate dispersion, a polyurethane dispersion, and a polyisocyanate crosslinker
Data Source
AI summary
The present invention relates to a polyacrylate dispersion comprising a multiphase acrylic polymer, the multiphase acrylic polymer comprising at least one vinyl polymer phase VP1 and one vinyl polymer phase VP2. the multiphase acrylic polymer being prepared by multiple step emulsion polymerization. The present invention also relates to an aqueous coating composition comprising the polyacrylate dispersion, a polyurethane dispersion, and a polyisocyanate crosslinker; to the use thereof in aqueous base coats. especially suitable in, but not limited to, automotive industry.