2K Epoxy Resin Composition for Catalyst-Free Ambient Cure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Epoxy resin compositions suffer from issues such as diminished fracture resistance, low thermal stability, poor flexibility, and hydrophobicity, with fast-curing blended systems causing phase separation and bubbling or bubbling in the cured composition, and the lack of adequate leveling in certain coatings, adhesives or sealants, and the inability to effectively address the physical properties of the cured product.
Innovation Solution
A two-component (2K) composition comprising a first component of epoxy resins and at least one elastomer modified epoxy resin, characterized by comprising a curative which consists of at least one compound possessing at least two epoxide reactive groups per molecule, said composition is characterized in that it is free of catalysts, wherein said composition is characterized in that the molar ratio of epoxide reactive groups provided in said curative to epoxide groups is from 0.90:1 to 1.2:1, preferably from 0.9:1 to 1.1:1, and the absence of catalysts, allowing for a dual cure mechanism under ambient conditions, resulting in a highly cross-linked system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If siloxane is incorporated into epoxy resin compositions through physical blending, then the negative properties of cured epoxy resin systems are mitigated, but the viscosity of the system increases and phase separation and bleeding of the siloxane component occur
Solution Approach 1:
The patent changes the chemical parameters of the siloxane component by introducing reactive functional groups (epoxide-reactive groups such as alkoxy, hydroxyl, carboxyl, or amine groups). This transforms the siloxane from a physically blended modifier to a chemically reactive component that forms covalent bonds with the epoxy resin, thereby maintaining composition stability while preserving the desired mechanical properties.
Solution Approach 2:
The patent creates a composite material system where siloxane oligomers with epoxide-reactive groups are chemically integrated into the epoxy resin matrix. This composite approach allows the siloxane to become part of the cross-linked network structure, preventing phase separation while maintaining the beneficial effects on fracture resistance and impact strength.
2Productivity
If blended systems are cured under catalysis, then the cure rate is fast, but adequate leveling in coatings and breathing of the material are limited, causing bubbling or buckling
Solution Approach 1:
The patent extracts the catalyst from the curing system, eliminating the need for catalytic acceleration. The curing process proceeds through direct chemical reaction between the epoxide groups and epoxide-reactive groups without catalyst intervention, thereby avoiding the harmful effects of fast catalyzed curing while still achieving complete cure.
Solution Approach 2:
The siloxane oligomers with epoxide-reactive groups serve as self-curing agents that react directly with the epoxy resin without requiring external catalysts. The system is self-sufficient, using the inherent reactivity of the functional groups to drive the curing process at a controlled rate that allows proper leveling and moisture escape.
3Productivity
If catalyzed reactions are used to cure blended systems, then the cure is fast, but gelation of the curing composition occurs which restricts molecular motion and retards proper development of physical properties
Solution Approach 1:
The patent removes the catalyst from the system to prevent premature gelation. The uncatalyzed reaction between epoxide groups and epoxide-reactive groups proceeds at a controlled rate that allows molecular motion to continue during curing, enabling proper development of physical properties without gelation restrictions.
4Reliability
If critical control of macromonomer blending ratio and resin to hardener ratio is implemented, then gelation is obviated, but the formulation complexity increases
Solution Approach 1:
The patent changes the chemical nature of the hardener from a traditional amine or anhydride to siloxane oligomers with epoxide-reactive groups. This parameter change allows for a simplified formulation where the siloxane oligomer itself serves as both the modifier and the curing agent, eliminating the need for separate hardener components and complex ratio 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 composition cures effectively under ambient conditions without catalysts, providing a stable and complete cure without compromising the physical properties of the cured product, achieving abrasion and corrosion resistance.
Implementation Method 1
the reaction of the two components of said composition provides a cured product exhibiting abrasion and corrosion resistance
Implementation Method 2
resulting in a highly cross-linked system
Implementation Method 3
allowing for a dual cure mechanism under ambient conditions, resulting in a highly cross-linked system
Data Source
AI summary
The present invention is directed to a two component (2K) composition comprising:(A) a first component comprising:a) at least one epoxy resin different from said resin b); and,b) at least one elastomer modified epoxy resin;(B) a second component comprising:c) a curative which consists of at least one compound possessing at least two epoxide reactive groups per molecule, said curative being characterized by comprising at least one alkoxy-containing aminofunctional silicone resin,wherein said composition is characterized in that it is free of catalysts.