Self-Stratifying Thermosetting Effect Coating Powder Composition

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Solution Overview

Problem

Existing effect coating powders often suffer from insufficient weatherability, durability, and optical appearance, particularly due to poorly separated coating layer interfaces and the need for multiple application and curing steps.

Innovation Solution

A self-stratifying multi-component thermosetting effect coating powder composition is developed, comprising a hydroxyl-functional polyester resin and a hydroxyl-functional acrylic resin, with a coloring agent in one component and effect pigments in the other, allowing for distinct layers to form upon curing without the need for multiple application steps.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If multiple coating layers are applied successively to achieve distinct functional layers, then the functional properties and optical appearance are improved, but the time consumption and energy usage increase due to multiple application and curing steps

Engineering Contradiction:
Improvefunctional propertiesVSAvoidtime consumption
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent combines multiple coating compositions into a single multicomponent powder mixture that self-stratifies during curing to form distinct functional layers. The primer composition, basecoat composition, and topcoat composition are merged in one application step, eliminating the need for successive coating applications while still achieving the functional benefits of multiple layers through differential migration and phase separation during the curing process.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If multiple coating layers are applied successively to achieve distinct functional layers, then the functional properties and optical appearance are improved, but the energy consumption increases due to multiple curing steps

Engineering Contradiction:
Improvefunctional propertiesVSAvoidenergy consumption
Core Design Contradiction:
ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The patent merges multiple curing operations into a single curing step by combining all coating compositions in one powder mixture. The multicomponent powder is applied once and then cured in a single energy treatment process, during which the compositions self-stratify to form distinct layers. This eliminates the need for multiple separate curing steps, significantly reducing energy consumption while maintaining the functional properties of each layer.

Inventive Principle:
Principle #5Merging (Combining)

3Illumination intensity

If effect pigments are increased to achieve pronounced optical effects, then the visual appearance is improved, but the weatherability and durability deteriorate

Engineering Contradiction:
Improveoptical effectsVSAvoidweatherability
Core Design Contradiction:
Illumination intensityVSReliability

Solution Approach 1:

The patent applies the local quality principle by creating distinct spatial zones with different compositions and effect pigment concentrations. The topcoat composition, which migrates to the surface layer, contains effect pigments for optical effects, while the primer and basecoat compositions provide protective and adhesive functions. This localized distribution allows pronounced optical effects at the surface without compromising the weatherability and durability provided by the other layers.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses composite materials by combining multiple coating compositions with different functions in a single multilayer structure. The topcoat layer acts as a protective barrier that contains effect pigments for optical effects, while the underlying primer and basecoat layers provide adhesion, corrosion protection, and color. This composite structure allows the effect pigments to deliver optical effects without being directly exposed to environmental degradation.

Inventive Principle:
Principle #40Composite materials

4Device complexity

If a single coating composition is applied to simplify the coating process, then the process complexity is reduced, but the functional properties and optical appearance deteriorate due to poorly separated coating layer interfaces

Engineering Contradiction:
Improveprocess complexityVSAvoidfunctional properties
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent employs self-service by designing a multicomponent powder mixture that automatically self-stratifies into distinct functional layers during the curing process without requiring external intervention or complex processing equipment. The different compositions migrate and separate based on their inherent properties (solubility parameters, reactivity, molecular weight), forming well-defined interfaces and distinct layers that provide the desired functional properties and optical appearance.

Inventive Principle:
Principle #25Self-service

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 resulting effect powder coatings exhibit improved balance between flexibility and strength, superior durability and weatherability, excellent color and effect retention, and enhanced gloss and shine retention, achieving pronounced optical effects with reduced effect pigment content.

Implementation Method 1

Coating powders are applied to a substrate, typically by means of an electrostatic process, such as an electrostatic spraying process

Methodology Applied
Scientific EffectElectrostatic deposition: Electrostatic Deposition

Implementation Method 2

the applied coating powder is treated with energy (such as heat) to form a powder coating onto the substrate. This energy treatment process is typically referred to as 'curing'

Methodology Applied
Scientific EffectThermal curing: Heating

Implementation Method 3

self-stratification. When applying a self-stratifying coating powder composition onto a substrate, separate layers with a different composition are formed upon cure

Methodology Applied
Scientific EffectSelf-stratification: Density Gradient

Data Source

PatentEP4538332A1Self-stratifying multicomponent thermosetting effect coating powder composition
Publication Date: 2025.04.16 TIGERWERK LACK & FARBENFAB
  • EP4538332A1 patent drawingFigure 1~2
  • EP4538332A1 patent drawingFigure 3~4
  • EP4538332A1 patent drawingFigure 5~6

AI summary

The present invention relates to a self-stratifying multi-component thermosetting effect coating powder composition, comprising component 1, which comprises a hydroxyl-functional polyester resin (A) and a crosslinker (C1), and component 2, which comprises a hydroxyl-functional acrylic resin (B) and a crosslinker (C2), wherein components 1 and 2 are each present in a multitude of discrete particles, the crosslinkers (C1) and (C2) are selected from the group of isocyanates, component 1 further comprises a coloring agent and component 2 further comprises effect pigments. The invention further relates to a process for producing a multi-component thermosetting effect coating powder composition, to an effect powder coating obtained by using the effect coating powder composition, and to a substrate being at least partially coated with the effect powder coating.