Michael Addition Coating Composition With Hardness Improvers
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Solution Overview
Problem
The Michael Addition curing system in industrial applications suffers from lower film hardness compared to traditional polyurethane curing systems, despite its advantages such as long pot-life, low VOC emissions, and excellent appearance.
Innovation Solution
Incorporating a hardness improver, such as silica or urea formaldehyde resin, with specific particle sizes and pH values, into the Michael Addition curable composition, particularly for epoxy resin-based reactive donors and acceptors, to enhance coating hardness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-generated harmful factors
If a Michael Addition curing system is used instead of traditional polyurethane curing, then VOC emissions are reduced and pot-life is extended, but film hardness decreases significantly
Solution Approach 1:
The patent combines Michael Addition curable resins with specific hardness improvers (silica, urea formaldehyde resin, or carboxymethyl cellulose) to create a composite coating system. This composite approach maintains the environmental benefits of Michael Addition curing while compensating for the hardness deficiency through synergistic material combination.
Solution Approach 2:
The patent modifies the coating system by introducing hardness improvers with specific physical and chemical parameters: silica or urea formaldehyde resin with particle sizes of 3-50 microns and pH ≥ 6.5, or carboxymethyl cellulose with degree of substitution 0.7-0.9 and viscosity 200-1000 mPa·s. These parameter specifications optimize the balance between cure chemistry and final film properties.
2Strength
If hardness improver is added to Michael Addition curable composition, then coating hardness increases by two or more pencil hardness levels, but the complexity of the formulation increases
Solution Approach 1:
The patent introduces hardness improvers with specific localized properties (particle size 3-50 microns, pH ≥ 6.5 for silica/urea formaldehyde; degree of substitution 0.7-0.9 for carboxymethyl cellulose) to address the hardness deficiency at specific points in the coating system without requiring complete reformulation of the entire composition.
3Strength
If silica or urea formaldehyde resin is used as hardness improver with particle size 3-50 microns and pH ≥ 6.5, then coating hardness is significantly enhanced, but the risk of aggregation and poor dispersion increases
Solution Approach 1:
The patent uses pH control (≥6.5 for silica and urea formaldehyde resin) and specific particle size ranges (3-50 microns) as intermediary parameters to optimize the interaction between hardness improvers and the Michael Addition curable resin system. These controlled parameters act as mediators that prevent aggregation while maintaining hardness enhancement, ensuring stable dispersion throughout the coating composition.
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 coating exhibits increased hardness, reaching two or more pencil hardness levels, while maintaining the benefits of the Michael Addition system, including long pot-life and low VOC emissions.
Implementation Method 1
C) at least one catalyst for catalyzing the Michael Addition crosslinking reaction between the at least one reactive donor and the at least one reactive acceptor
Data Source
AI summary
The present disclosure relates to a Michael Addition curable composition, coating composition containing the same and coated article made therefrom. In particular, the Michael Addition curable composition, comprises A) at least one reactive donor capable of providing two or more nucleophilic carbanions; B) at least one reactive acceptor comprising two or more carbon-carbon double bonds; C) at least one catalyst for catalyzing the Michael Addition crosslinking reaction between the reactive donor and the reactive acceptor; and D) at least one hardness improver, wherein the at least one reactive donor has a backbone based on an epoxy resin; and wherein the at least one hardness modifier is one or more selected from silica and urea formaldehyde resin, and the at least one hardness modifier has a particle size in micrometers and the at least one hardness modifier has a pH value of 6.5 or higher.