Waterborne Epoxy Silane Oligomer Synthesis via Controlled Hydrolysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Monomeric epoxy silanes in water-based systems face challenges due to sensitivity to hydrolysis and condensation, difficulty in controlling epoxy functionality stability, and the release of volatile organic compounds (VOCs), making it hard to create water-soluble, corrosion-resistant coatings with superior adhesion and weathering properties.
Innovation Solution
A process involving the reaction of glycidoxy silane and/or cycloaliphatic epoxy silane with less than 1.5 equivalents of water in the presence of a catalyst, with continuous water feeding, to produce a waterborne epoxy silane oligomer that is pre-solubilized in an acidic aqueous solution with optional ingredients like surfactants and pH adjusting agents, enhancing water solubility and stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If monomeric epoxy silanes are used in water-based systems, then the coating can be applied, but the system suffers from sensitivity to hydrolysis and condensation, difficulty in controlling epoxy functionality stability, and release of VOCs
Solution Approach 1:
The patent segments the monomeric epoxy silane into oligomeric structures with controlled molecular weights (average 2-10 repeating units). This segmentation reduces the sensitivity to hydrolysis and condensation while maintaining epoxy functionality stability, as the oligomeric structure provides better steric protection and controlled reactivity compared to monomeric species.
Solution Approach 2:
The patent creates composite oligomeric structures combining silane units with epoxy functionalities in a controlled architecture. The oligomeric nature with specific molecular weight ranges (achieved through controlled condensation) provides a composite structure that simultaneously delivers water solubility, hydrolysis resistance, and epoxy stability, eliminating the VOC issues associated with monomeric alkoxy groups.
2Ease of operation
If pre-hydrolyzed and pre-condensed silane oligomers are used, then film formation and dispersion properties improve, but high molecular weight oligomers condense further to form structures that are difficult to make water-soluble
Solution Approach 1:
The patent precisely controls the molecular weight parameter of the oligomers by limiting the condensation degree to average 2-10 repeating units. This parameter control maintains water solubility while achieving adequate film formation. The controlled molecular weight prevents excessive condensation that would lead to water-insoluble networks, thus balancing film formation capabilities with water solubility requirements.
3Productivity
If high molecular weight oligomers are used, then curing rates increase, but the oligomers condense further to form structures that are difficult to make water-soluble
Solution Approach 1:
The patent optimizes the molecular weight parameter by controlling the oligomer structure to have average 2-10 repeating units. This controlled parameter range achieves sufficient curing rates (faster than monomers) while preventing excessive molecular weight that would compromise water solubility. The balanced oligomeric structure provides adequate reactivity for fast curing without forming water-insoluble networks.
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 waterborne epoxy silane oligomer exhibits good water solubility, improved stability, and reduced VOC emissions, enabling the creation of coatings with enhanced corrosion resistance, adhesion, and weathering performance suitable for various substrates.
Implementation Method 1
reacting glycidoxy silane and/or cycloaliphatic epoxy silane with less than 1.5 equivalents of water in the presence of a catalyst
Implementation Method 2
pre-hydrolyzed and pre-condensed silanes can be an oligomeric structure that has specific features like controlled molecular weight
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A process for producing an epoxy silane oligomer including a reaction glycidoxy silane and/or cycloaliphatic epoxy silane having 2 or 3 alkoxy groups and, optionally, a copolymerizable silane other than glycidoxy and cycloaliphatic epoxy silane, with less than 1.5 equivalents of water in the presence of a catalyst, wherein said water is continuously fed during the reaction.