Multilayer Color-Effect Coating With Control Particles for Uniform Optics
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Solution Overview
Problem
Existing coating technologies face challenges in achieving uniform optical properties independent of viewing angle due to anisotropic orientation of platelet-shaped pigments, leading to costly and uneven surfaces, especially in multilayer coatings for motor vehicle bodies.
Innovation Solution
Incorporation of control particles with defined size distribution in the basecoat layer to control the orientation of color and effect pigments, ensuring an isotropic arrangement despite directed application methods, thereby reducing angular dependence of optical properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a basecoat layer is applied by a directed application method (rolling or knife coating), then the platelet-shaped pigments are oriented in a preferential direction, but the optical properties become dependent on the viewing angle
Solution Approach 1:
The patent introduces a surfacer layer as an intermediary between the substrate and the basecoat layer. This surfacer layer, applied by an undirected application method (spray application), contains platelet-shaped pigments that are isotropically distributed. The surfacer layer acts as a mediator that optically masks the anisotropic orientation of pigments in the basecoat layer, thereby eliminating viewing angle dependence while allowing the basecoat to be applied by a simple directed method.
2Stability of the object's composition
If a basecoat layer is applied by an undirected application method (spray application), then the pigment orientation is isotropic, but the coating film thickness becomes uneven
Solution Approach 1:
The patent divides the basecoat application into two separate layers: a primary basecoat layer applied by a directed application method (providing uniform thickness) and a secondary basecoat layer applied by an undirected application method (providing isotropic pigment orientation). This segmentation allows each layer to fulfill its specific function, with the secondary layer being comparatively thin so as not to compromise the thickness uniformity achieved by the primary layer.
3Reliability
If a multilayer coating system is used with primer, surfacer, basecoat, and clearcoat layers, then the coating provides comprehensive protection and aesthetic properties, but the coating process becomes more complex and costly
Solution Approach 1:
The patent applies the principle of local quality by giving each layer a specific, localized function: the primer layer provides adhesion and corrosion protection, the surfacer layer provides optical masking and isotropic pigment distribution, the basecoat layer provides color and effect with uniform thickness, and the clearcoat layer provides protection and optical enhancement. This functional differentiation allows the multilayer system to achieve comprehensive performance while maintaining a logical and manageable process structure.
Data Source
AI summary
A multilayer color and/or effect coating on a substrate, wherein the coating includes a clearcoat layer having a dry film thickness of 10 μm to 50 μm, and the coating includes a basecoat layer having a dry film thickness of 6 μm to 35 μm, incorporating color and/or effect pigments whose orientation within the basecoat layer influences the optical properties of the coating, and the basecoat layer includes control particles that control the orientation of the color and/or effect pigments, wherein the control particles are characterized by a d10 of at least 50% of the dry film thickness of the basecoat layer and by a d50 of 80% to 120% of the dry film thickness of the basecoat layer, and by a d100 of not more than 200% of the dry film thickness of the basecoat layer.