Multilayer Sparkling Coating With Glass Flakes and Joint Curing

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Solution Overview

Problem

Existing multilayer coatings in the automotive industry face challenges in achieving a high degree of sparkle and luster while maintaining good mechanical properties such as adhesion to the substrate and intercoat adhesion, and are limited by the amount of effect pigments that can be included due to industrial applicability, price, and storage stability issues.

Innovation Solution

A process involving the application of a composition comprising platelet glass flake pigments with specific size ranges directly onto a substrate, followed by sequential application and joint curing of basecoat and clearcoat layers, utilizing a combination of binders, solvents, and glass flake pigments to enhance sparkle and luster without altering standard application methods.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Illumination intensity

If the amount of effect pigments is increased to achieve higher sparkle and luster, then the aesthetic quality improves, but the storage stability and price increase

Engineering Contradiction:
Improvesparkle and lusterVSAvoidstorage stability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent changes the particle size parameter of glass flake pigments, using a bimodal distribution with particles of 30-54 μm and 55-80 μm. This parameter optimization allows achieving high sparkle and luster with lower overall pigment concentration, thereby improving storage stability while maintaining aesthetic quality.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent uses a composite approach by combining glass flake pigments with specific binder systems (polyester, polyurethane, or acrylic resins) and crosslinking agents. This composite formulation enhances the optical properties and storage stability of the coating composition.

Inventive Principle:
Principle #40Composite materials

2Illumination intensity

If effect pigments are added to enhance sparkle, then the aesthetic quality improves, but the price increases

Engineering Contradiction:
Improvesparkle and lusterVSAvoidprice
Core Design Contradiction:
Illumination intensityVSQuantity of substance

Solution Approach 1:

The patent optimizes the particle size parameters of glass flake pigments to achieve maximum light reflection and sparkle effect at lower concentrations. The bimodal size distribution (30-54 μm and 55-80 μm) creates enhanced optical effects with reduced material quantity, thereby lowering cost.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies effect pigments selectively in a sparkling coat layer rather than uniformly throughout all coating layers. This localized application concentrates the aesthetic effect where most visible while reducing overall pigment consumption and cost.

Inventive Principle:
Principle #3Local quality

3Illumination intensity

If glass flakes with specific size ranges are used to enhance sparkle, then the luster improves, but the manufacturing complexity increases

Engineering Contradiction:
ImprovelusterVSAvoidmanufacturing complexity
Core Design Contradiction:
Illumination intensityVSDevice complexity

Solution Approach 1:

The patent specifies precise particle size parameters (D90 values of 30-54 μm and 55-80 μm) for glass flake pigments. These standardized parameter ranges allow for consistent quality control and simplified manufacturing processes while achieving superior luster and sparkle effects.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the glass flake pigment population into two distinct size groups (30-54 μm and 55-80 μm) with a gap between them. This segmentation creates optimal light reflection properties while using commercially available standardized particle size distributions, simplifying the manufacturing process.

Inventive Principle:
Principle #1Segmentation

4Illumination intensity

If multiple coating layers are applied sequentially, then the aesthetic quality and protection improve, but the production time increases

Engineering Contradiction:
Improveaesthetic qualityVSAvoidproduction time
Core Design Contradiction:
Illumination intensityVSProductivity

Solution Approach 1:

The patent merges the sparkling effect function into a dedicated sparkling coat layer that is jointly cured with surrounding coating layers. This consolidation achieves aesthetic quality enhancement while reducing the number of separate curing cycles, thereby improving productivity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent applies the sparkling coat layer containing optimized glass flake pigments as a preliminary layer before final clearcoat application. This preliminary action ensures sparkle effect is established early, and subsequent layers provide protection without requiring additional sparkle-enhancing steps.

Inventive Principle:
Principle #10Preliminary action

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 process produces multilayer coatings with outstanding sparkle and luster, along with improved adhesion to the substrate and intercoat adhesion, suitable for use in the automotive industry without modifying existing application methods, and capable of enhancing color tone variants.

Implementation Method 1

applying a composition (Z2) directly to the basecoat layer (BL2a) or the uppermost basecoat layer (BL2-z) or the clearcoat layer (C1) to form a coating layer (L3)

Methodology Applied
Scientific EffectDeposition: Deposition (physical)

Implementation Method 2

joint curing of all applied layers

Methodology Applied
Scientific EffectCuring: Chemical Bonding

Data Source

PatentUS12569879B2Process for producing a multilayer coating comprising a sparkling coat layer and multilayer coating obtained from said process
Publication Date: 2026.03.10 BASF COATINGS GMBH

AI summary

Described herein is a process for producing a multilayer coating (MC) on a substrate (S), the process including producing at least one basecoat layer, optionally at least one clearcoat layer, at least one layer including a mixture of glass flakes and at least one further clearcoat layer and jointly curing all applied layers. Also described herein is a multilayer coating obtained by the described process.