Low-Viscosity Allophanate Binders via Phenoxide Catalysis
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Solution Overview
Problem
The preparation of low-viscosity radiation-curing allophanates with activated double bonds at temperatures below 100°C is not adequately disclosed in existing technologies, leading to potential polymerization issues during the purification process of polyisocyanates.
Innovation Solution
A process involving the reaction of uretdiones with alcohols containing activated double bonds, using phenoxide salts as catalysts, to produce binders with allophanate groups capable of polymerizing with ethylenically unsaturated compounds upon actinic radiation exposure, while maintaining low viscosities and minimizing thermal initiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If polyisocyanates are purified by distillation at temperatures up to 135°C to reduce residue isocyanate content, then isocyanate purity is improved, but premature polymerization of activated double bonds occurs due to thermal initiation
Solution Approach 1:
The patent changes the temperature parameter from conventional distillation temperatures (up to 135°C) to reduced temperatures (below 100°C, preferably 60-90°C) by using alternative purification methods such as extraction with water-soluble compounds, thereby preventing thermal initiation of polymerization while still achieving sufficient isocyanate purity
Solution Approach 2:
The patent introduces water-soluble compounds (extractants) as intermediary substances to remove residue isocyanates from the polyisocyanate mixture through extraction, replacing the direct thermal distillation method that causes premature polymerization
2Quantity of substance
If conventional distillation methods are used to purify polyisocyanates, then isocyanate content is reduced, but the process complexity and energy consumption increase due to high temperature requirements
Solution Approach 1:
The patent changes the temperature parameter from conventional distillation temperatures (up to 135°C) to reduced temperatures (below 100°C, preferably 60-90°C) by using alternative purification methods such as extraction with water-soluble compounds, thereby preventing thermal initiation of polymerization while still achieving sufficient isocyanate purity
Solution Approach 2:
The patent replaces the mechanical/thermal distillation system with a chemical extraction system using water-soluble compounds, eliminating the need for high-temperature heating and associated energy consumption
3Stability of the object's composition
If high temperatures (≥120°C) are used for ring opening of uretdiones with alcohols, then allophanate formation is improved, but radiation-curing monomers cannot be prepared due to excessive temperature
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperatures (≥120°C) to reduced temperatures (below 100°C, preferably 60-90°C) by using alternative purification methods such as extraction with water-soluble compounds, thereby preventing thermal initiation of polymerization while still achieving sufficient isocyanate purity
Solution Approach 2:
The patent introduces water-soluble compounds (extractants) as intermediary substances to remove residue isocyanates from the polyisocyanate mixture through extraction, replacing the direct thermal distillation method that causes premature polymerization
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
This method effectively produces binders with viscosities of ≤100,000 mPas at 23°C, achieving targeted allophanate formation without premature polymerization, suitable for use in coating compositions and other applications.
Implementation Method 1
The reaction of uretdiones with alcohols containing activated double bonds, using phenoxide salts as catalysts, to produce binders with allophanate groups
Implementation Method 2
groups capable of participating in a polymerization reaction with ethylenically unsaturated compounds on exposure to actinic radiation
Data Source
AI summary
A process for preparing binders containing allophanate groups which contain, at the oxygen atom of the allophanate group that is bonded via two single bonds, organic radicals with activated groups capable of participating in a polymerization reaction with ethylenically unsaturated compounds on exposure to actinic radiation; the process includes reacting A) one or more compounds containing uretdione groups with B) one or more OH-functional compounds which contain groups capable of participating in a polymerization reaction with ethylenically unsaturated compounds on exposure to actinic radiation, and C) optionally further NCO-reactive compounds, and D) in the presence of one or more compounds containing phenoxide groups, as catalysts. The binders can be used in preparing coatings, coating materials, coating compositions, adhesives, printing inks, casting resins, dental compounds, sizes, photoresists, stereolithography systems, resins for composite materials and sealants.