Cyclic Carbonate Bonding Agent for Moisture-Sensitive Adhesion
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Solution Overview
Problem
Two-component polyurethane bonding systems based on NCO-terminated compounds face issues with moisture sensitivity and toxicity from monomeric isocyanates, leading to quality loss and contamination risks, especially in packaging and food industries.
Innovation Solution
A bonding agent system comprising a compound with at least two cyclic carbonate groups and a compound with (—NHR—) atom groupings, where the NCO group content is less than 0.1 wt.%, providing good adhesion and sealing properties without the drawbacks of traditional systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If NCO-terminated compounds are used as curing agents in polyurethane bonding systems, then good adhesion and bonding performance are achieved, but moisture sensitivity and toxicity from monomeric isocyanates occur
Solution Approach 1:
The patent removes the harmful NCO groups from the curing agent composition by using alternative curing mechanisms. Instead of relying on isocyanate groups that cause moisture sensitivity and toxicity, the invention employs polyols with hydroxyl groups that react with isocyanate-containing substrates through a different chemical pathway, thereby extracting the harmful element while preserving bonding functionality.
Solution Approach 2:
The patent changes the chemical parameters of the curing agent by substituting NCO-terminated compounds with polyols having specific hydroxyl group content (5-50 mg KOH/g). This parameter change transforms the curing mechanism from NCO-based to hydroxyl-based reaction, eliminating the harmful properties associated with monomeric isocyanates while maintaining adhesion performance.
2Reliability
If monomeric diisocyanates are used in the curing component, then curing performance is improved, but toxic migration into packaging materials and products occurs
Solution Approach 1:
The patent introduces polyols as intermediary substances that mediate the curing process. These polyols react with isocyanate groups in the substrate to form urethane linkages, serving as a buffer that prevents direct migration of monomeric diisocyanates into packaging materials. The polyol acts as a intermediary reaction layer that maintains curing performance while blocking harmful migration pathways.
Solution Approach 2:
The patent creates a composite curing system combining polyols with specific hydroxyl content and isocyanate-containing substrates. This composite approach forms a multi-component bonding system where the polyol matrix incorporates and stabilizes the isocyanate reaction products, preventing their migration while maintaining the curing function through the combined chemical system.
3Ease of operation
If residual moisture is present in polyol components, then ease of operation is improved, but unwanted bubbles form in the adhesive film
Solution Approach 1:
The patent converts the harmful effect of residual moisture into a beneficial feature by using polyols with controlled hydroxyl group content (5-50 mg KOH/g). This controlled moisture content actually improves ease of operation and mixing while the specific polyol composition prevents bubble formation. The invention transforms the problematic moisture issue into an advantageous property through precise compositional control.
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 system offers excellent adhesion to various materials, reduces the risk of contamination, and eliminates the need for costly protective measures, while maintaining product quality and safety.
Implementation Method 1
a compound with at least two cyclic carbonate groups... and a compound with at least two (—NHR—)-atom groupings
Data Source
AI summary
A bonding agent system is provided that contains at least components (A) and (B), where (A) is at least one compound with at least two cyclic carbonate groups and (B) is at least one compound with at least two primary and/or secondary amine groups. The bonding agent system is particularly suitable for use as a two-component adhesive or sealant and has very good adhesion to various substrates.