Latent Base Catalyst System for Crosslinkable Coatings
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
High solids crosslinkable compositions face challenges in achieving a balance between rapid curing and long pot life, especially at low to moderate temperatures, due to limitations in existing latent base catalysts which often result in short pot life and inadequate drying behavior.
Innovation Solution
A crosslinkable composition using a combination of a first carbonate salt as a latent base catalyst and a second carbonate salt as a potlife extender, which decomposes to release a strong base for curing while maintaining a stable viscosity, allowing for longer application times and fast drying without yellowing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a strong base catalyst is used to achieve rapid curing, then the curing reaction speed is improved, but the pot life becomes short due to premature crosslinking
Solution Approach 1:
The patent applies parameter changes by using a blocked catalyst system where the catalyst activity is modulated through chemical blocking. The catalyst precursor is converted to an active strong base catalyst through decomposition or reaction with water, allowing control over the timing and rate of crosslinking. This enables rapid curing when needed while maintaining stability during storage and application.
Solution Approach 2:
The patent employs preliminary action by pre-blocking the catalyst in an inactive form (catalyst precursor) that is stable during storage and application. The blocking agent is removed or decomposed under curing conditions, activating the catalyst at the desired time. This preliminary blocking state extends pot life while ensuring rapid curing activity is available when the coating is applied.
2Object-affected harmful factors
If high solids content is used to reduce VOC levels, then environmental compliance is improved, but the balance between rapid drying and long pot life becomes difficult to achieve
Solution Approach 1:
The patent uses parameter changes by implementing a blocked catalyst system that allows high solids content formulations to maintain both long pot life and rapid drying capability. The catalyst activity is controlled through the blocking mechanism, enabling the system to remain stable at high solids content during storage and application, then rapidly cure when applied, achieving the desired balance without compromising environmental compliance.
3Productivity
If more catalyst is added to accelerate curing, then the drying rate is improved, but the pot life is shortened
Solution Approach 1:
The patent applies parameter changes by using a blocked catalyst system where the effective catalyst concentration is controlled through the blocking mechanism rather than simply adding more catalyst. The blocking agent prevents premature activation, allowing higher catalyst loadings to be used without shortening pot life. When cured, the blocked catalyst decomposes to provide high levels of active catalyst for rapid drying, thus improving productivity without sacrificing pot life.
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 solution provides a good balance of extended pot life and rapid curing, even at low temperatures, with the ability to use higher catalyst amounts without shortening pot life, and prevents yellowing under stoving conditions, making it suitable for various coating applications.
Implementation Method 1
A crosslinkable composition using a combination of a first carbonate salt as a latent base catalyst and a second carbonate salt as a potlife extender, which decomposes to release a strong base for curing
Implementation Method 2
A composition crosslinkable by Real Michael Addition (RMA) reaction comprises a component with at least 2 activated unsaturated groups and a component with at least 2 acidic protons C—H in activated methylene or methine groups, that can react and crosslink to each other in the presence of a strong base catalyst
Data Source
AI summary
A crosslinkable composition including at least one crosslinkable component that is crosslinkable under the action of a base catalyst, a first carbonate salt according to a first formula as latent base crosslinking catalyst, and a second carbonate salt according to a second formula as potlife extender, wherein the second carbonate is present in an amount of at least 5 mole % and preferably at most 500 mole % relative to the molar amount of the first carbonate. Further disclosed are catalyst compositions composed of the first and second carbonate salts, to the use of the catalyst composition as base catalyst system in crosslinkable compositions and the crosslinkable compositions, in particular coating compositions comprising the catalyst composition.